my 2 cents:

Unless you're towing, or dealing with extreme whether, these CRD's run just fine without a fan.

My OEM clutch was doing virtually nothing, and I never noticed an issue until I slapped a 24' travel trailer behind her and pulled up a mountain pass.


In terms of Electric vs Mechanical fan.......

I'm sure in most cases, an electric fan would be considered "good enough" (especially considering these CRD's work will without a fan) but let's not kid ourselves here.....

How many amps are our alternators? 60? 100? even if they're 100 amps, 100 x 13 is 1300 watts. 1300 watts is like 1.5 HP.

So even if you had a fan using up your ENTIRE alternator's output, it would only be the equivalent of like 1.2 HP of air flow. (electric fans are far from 100% efficient too)

In reality, those fans run off.... 10 amps? 15 amps? 15 x 13 = 195 watts?

When those fan clutches are working properly, and when they "lockup" and when your turning 3000+ RPM up a big hill, there is one hell of a lot more mechanical draw off the engine then 195 watts.... it's probably more like 3-7 HP, which with all the efficiency losses would be the electrical equivalent of like 3000-10000 watts of electrical power needed to match that.


Just consider the SOUND the mechanical fan can make, and factor in the size of those fan blades.

An electric fan with the same size blades wouldn't make nearly as much noise.


And before someone starts talking about CFM.....

These fans are not "free flowing"....

A household box fan can move a decent amount of air with not that much electrical power, true...
But in the case of a vehicle, you need to suck that air through the ultra-restrictive (relative to free flowing) radiator and AC condenser.

So maybe a household box fan could move 5000 CFM off 130 watts, but a situation like this is more like a household vacuum...

A household vacuum takes like 1200 watts to move like 100 CFM of air....


The energy required to pull air through a the openings of the ac condenser and the radiator would be somewhere between a household box fan and a household vacuum..

And it would not be a linear curve, meaning each additional CFM would take more HP.

So, my 2 cents, if you don't plan on towing in hot weather up big hills, then sure, go with an electric fan, but understand that it will never be able to match the real world cooling power of a proper, working mechanical fan.

Our alternator is 130 amps.

A 12v automotive fan motor in good condition will pull about 15 amps at startup, then about 8-10 amps when running at a steady speed.

Because I ran into a few situations when driving at slow speed and high load (steep hill climb) and AC-off (=electric fan off) and saw coolant temps go waaay high, I made a simple modification to the fan control circuit.
My electric fan is now on at LOW speed at all times while the engine is running and I have a toggle switch to turn it up to HIGH speed when needed.
However, 100F summer afternoon + slow moving traffic + AC-on = high coolant temps, even with the fan at high speed.
Turning the AC-off helps bring temps back down.

Also, I'm thinking about putting vent louvers in the hood. Maybe that will help the hot air escape the engine bay.

_________________
U.S. Army Retired

Have you considered the OEM fan with a hayden clutch? It's pretty bomb-proof, and cheap.


All the people trying to sell you electric fans will talk about parasitic losses, etc, but the reality is, if the fan clutch is working properly, there is very little energy lost to a mechanical fan.

And if the idea is to move air via mechanical energy....

Crankshaft ---> belt --> pulley --> clutch ---> fan

is one hell of a lot more efficient than

Crankshaft --->belt-->pulley-->alternator-->electrical system--->electric motor--->fan

Even the best alternators are only like 60% efficient, so right off the bat, you're losing at least 40% of your energy, not to mention the efficiency of the electric motor in the fan....

You've already got mechanical energy just sitting there, why convert it to electrical and back again? And on top of that, limit the amount of energy that you can convert to cooling by the size of the electric motor / fan vs the fan clutch / fan.


Commercial Tractor / Trailers are a great example, those things are built to last and tow massive loads..All while trying to achieve the best possible efficiency....
they use mechanical fans for a reason.

In fact, in most automotive applications where a mechanical fan is possible, and the GVW of the vehicle is high, they use them.

And another thing to consider:

GVW vs frontal area.

These liberties have very high GVW's (relative to other vehicles the same size, like say a ford escape)

Go look at a 1 tonn pickup. Massive front grill, massive radiators, massive airflow.

We're trying to cool an engine dealing with high weight loads with this tiny little front grill. It's going to take a lot of air flow through a very restrictive opening to keep it cool.

Hood louvers probably will help some. But I believe if you put a 11 blade fan and HD Hayden fan clutch on the motor it will solve your slow speed + AC-on = high coolant temps problem. I can tell you we have had some 100+ degree days here in the past few weeks and I got stuck in some stop and go traffic on I 285 for about an hour and my temperature never moved past the halfway mark on the gauge with AC on full blast.

I also thought the electric fan is supposed to cut on if the engine coolant temperature rises above a certain point even with the AC system off? Thought I read that somewhere?
Was yours not doing that which necessitated the wiring change and toggle switch?

_________________
Supporting Vendor and Moderator of LOST
05 Jeep Liberty CRD Limited
Ironman Springs/Bilstein/Shocks
Yeti StgIV Hot Tune
Week's BatteryTray
No FCV/EGR
Samcos/ProVent
SunCoast/Transgo
Carter Intank-pmp
2mic.Sec.Fuel Filter
Flowmaster/NO CAT
V6Airbox/noVH
GM11 Bld.fan/HDClutch
IronrockArms/wwdieselMount
98 Dodge Cummins 24 Valve

[/quote]Our alternator is 130 amps.

A 12v automotive fan motor in good condition will pull about 15 amps at startup, then about 8-10 amps when running at a steady speed.

Because I ran into a few situations when driving at slow speed and high load (steep hill climb) and AC-off (=electric fan off) and saw coolant temps go waaay high, I made a simple modification to the fan control circuit.
My electric fan is now on at LOW speed at all times while the engine is running and I have a toggle switch to turn it up to HIGH speed when needed.
However, 100F summer afternoon + slow moving traffic + AC-on = high coolant temps, even with the fan at high speed.
Turning the AC-off helps bring temps back down.

Also, I'm thinking about putting vent louvers in the hood. Maybe that will help the hot air escape the engine bay.[/quote]


flash7210:

How much is it going to cost you to put vent louvers in the hood of your CRD? Perhaps you should be communicating with bshooter.... here is his posting on page 31 of my thread "ADD YOUR NAME HERE IF YOU WANT A NEW DESIGN THERMOSTAT"...

"I haven't been involved too much on LOST Lately... I do love this site for Information. I also posted all my info about the SFA Transformation of my daily driver a 2006 CRD to an all out Off-Road Jeep. "The Gremlin". She is running 513 gears, 241or T-case, GDE tuned Engine and Transmission, Completely Home made Cold air intake, Griffin Radiator with F&F Dynamics E fan, Larger intercooler with home made piping, 14" ORI Struts, Tom Woods drive shafts, Reid Knuckles, RCV's up front and Chrome Molly rear shafts in the rear, Lower Triangulated 4-link front Suspension and Upper Triangulated 4-link rear Suspension, all sitting on 12" MRW 40 Bolt Extreme Bead-locks with 39.5x16.5/17 Pitball Rockers.. I am telling you this because, This Jeep is Extreme and this 2.8 TD is worked very hard.. I did have some higher Engine Temp's when driving down the road @ 60 mph. Maybe you can see why.. Lol...After Installing The H.D.S Model 001 Thermostat My Engine with the 203* Thermostat Runs EXACTLY @ 203* ALL THE TIME. Once she reaches the 203* she runs that way ALL DAY LONG even with all this extra weight and strain on the running gear... My F&F Dynamic E fan is set as Close to coming on at 203* It dose not come on, I have to turn it on a couple times a day just so make sure its working correctly, and it is.... The Design and Machine Work put into the making of the H.D.S Model 001 Thermostat is Greatly Appreciated by someone like my self who has great investments in Jeep. Comparing the Stock Thermostat side by side with the H.D.S Model 001 is By Far "THE BEST IMPROVEMENT YOU CAN GET" for maintaining Consistent Engine Temperature on our CRD's. I highly Recommend this Thermostat for The CRD Liberty even for a build like mine... I guarantee I put more stress on my engine then you do..."

The flow characteristics of the cooling system fan - either electric or mechanical - are a factor in determining the overall efficiency and capacity of any engine's cooling system. However, in the case of the CRD, it is by no means the most important factor... the engine thermostat assembly is.

I keep trying to tell members here on LOSTJEEPS.com that the problem with the O.E. thermostat assembly is not only the fact that it opens up too soon at 80 degrees Celsius or 176 degrees Fahrenheit, but that the thermostat housing itself is too restrictive for good coolant flow when the engine is being worked hard or driving in extremely hot conditions. My partner, myself and the engineers I consulted when designing the Hot Diesel Solutions Model 001 determined that the only safe thing to do if we were to significantly increase operating temperatures of the CRD engine was to increase coolant flow... this meant we had to have a completely new housing and cap appropriately sized for the larger Hemi thermostat valve we intended to use... simply stuffing a Hemi thermostat in the O.E. housing and welding on adaptor rings will not get the increased coolant flow we were looking for. This is the main reason why the Model 001 is so expensive to manufacture... we determined that the O.E. housing was useless for our purposes and had to go with a new design.

bshooter lives in Florida - one of the states in the U.S. with the HOTTEST climate, and he is putting his Liberty CRD through driving conditions that almost nobody else encounters with a driveline that really works his engine hard. He is using an ELECTRIC fan, which does not pull as much CFM as the O.E. mechanical fan, and therefore his cooling system's capacity for cooling is reduced in this factor.

Despite all of this, he is running the HOTTEST thermostat valve available with my design, which is 27 degrees hotter than the O.E. valve, and yet he is not overheating. The ONLY reason he can get away with all of the extreme equipment he has installed and all of the stress he puts his engine through without overheating is the fact that the H.D.S. Model 001 flows more coolant than the O.E. assembly.

Yes.
With the AC off, the electric fan will come on when coolant temps get above 205.
But that is too high a temp for getting things cooled down while you are climbing the hill.

_________________
U.S. Army Retired

Water can hold a crap-ton of thermal energy.

What are your engineering numbers for the stock system?

How many LPM or GPM does the stock system move through the radiator with the stock T-stat wide open?


Those numbers can provide you with a maximum temperature delta and you can go from there.

IE: 200,000 BTU of thermal energy can heat ~11 GPM of water by 35 degrees F.

So if our engines make 200,000 BTU of heat (I pulled that number out of my booty for the record, just trying to make an example)
And our water pumps move 11 GPM of water (again, number out of my booty)
Then our radiators would theoretically be something in the neighborhood of 35 degrees F less than the engine. (amusing a steady state of engine heat, where BTU's generated by the engine is equal to BTU's cooled by the rad / fan)


So if you're trying to cool an engine at 190 degrees F, your radiator would only be at 155 degrees F. And your radiator would be interfacing with air presumably at something like 100 degrees F (assuming hot 100 degree day for poops and giggles)


So what you're saying is that the water flow through the engine is so restrictive that the radiator can't operate efficiently because it can't generate a large enough thermal delta over the air going through it.

Interesting.


For the record, I believe 11 GPM can easily pass through a 1/2 water pipe, our rad hoses are much greater than that.

it looks like a typical diesel engine makes 2,500 BTU's per hour of brake horsepower

our engines are 160 HP, so that's 400,000 BTU's

Huh, that makes my math pretty easy given my previous numbers...

to keep a 35 degree delta between the engine and the radiator (again, assuming steady state heat in / heat out), you would need 22 GPM of water flow.

Obviously the lower the delta, the more effective/efficient the radiator will be....

Now.... how to figure out the water flow through our system, I wonder.... what did you guys come up with?

It looks like performance small block pumps are like 40-50 GPM (advertised, I bet the truth by the time they go through a T-stat less)

But still.... makes my 22 GPM number out of my booty seem.... plausible...

What numbers did you guys come up with?

About $80 if I do all the work myself.

_________________
U.S. Army Retired

Sorry, crd260, but you are incorrect for a number of reasons:

Automotive manufacturers have been incorporating to electric cooling fans for years now because it has been determined that an electric cooling fan is more efficient and saves fuel over using a mechanical fan alone or with the old style heat activated clutch. They have been forced by government legislation over the years to increase fuel efficiency of the vehicles they sell, and have access to multi-million dollar research facilities to determine what can be done to achieve this. Auto manufacturers being profit driven, are always going to develop those technologies that achieve their goals as cheaply as possible. Developing reliable electric cooling fan technology was therefore one of the things they developed first; even before fuel injection, (with a few notable exceptions, of course).

Heat activated mechanical fan clutches have been around for generations now; they are definitely old-school and not a good design. They are ALWAYS partially engaged and therefore are putting a parasitic drag on the engine even when they are not needed. For this reason alone a mechanical fan with a heat activated clutch is not as efficient as an electric fan, even considering the losses in efficiency powering an alternator to produce electricity to run the electric cooling fan, (and I am not convinced by your estimation in losses of efficiency).

When you speak of commercial vehicles with mechanical cooling fans, you are in almost all cases speaking about a mechanical fan that is engaged by an electro-mechanical or pneumatic clutches. These clutches are light-years ahead of the old heat activated mechanical clutches used in the automotive and light-duty truck industry, because they completely disengage when not needed and are much more robustly built to withstand commercial use. An electro or pneumatic fan clutch CAN save you on fuel and loss of power when not in use, but they require a very strong fan that can withstand being instantly engaged. If you can even find an electro or pneumatic fan clutch to fir the Liberty CRD application, you can’t use the same fan blades or you would risk sending one or more of those blades through your hood after being bolted onto one of these clutches for a while.

The electro or pneumatic clutch solutions is the best for any vehicle application where heavy-duty towing is required, and is the ultimate answer to anyone wanting the best airflow through the radiator while still having minimal parasitic fuel and power losses to the engine. I have already looked into this solution, and NOBODY is making anything close to small enough for passenger vehicle applications, and to develop one is astronomically expensive.

Horton products does still make a clutch for the original 12 valve 5.9L Cummins engine on the Dodge heavy-duty pickups, but it is around $1000.00 USD for one of them. You also have the additional expense of having to get a special wiring harness and fan assembly made up by a shop in Texas, (I forgot the name). You are looking at an expense of at least $1500.00 USD total to get this technology installed in a 20 year old Dodge pickup truck.... ouch!!

Given the fact that bshooter is running a very radically modified Liberty CRD - with a 203 degree Hemi thermostat valve in a H.D.S. Model 001 - off-road in hot weather with a FF Dynamics electric cooling fan and is NOT overheating, I would definitely say that the electric cooling fan solution with his Model 001 is probably going to be fine for mass-hole's application. It could be that his Hayden fan clutch is failing, or there may be some other issue causing the overheat conditions.

The even heavier weight of bshooter's CRD with all of his off-road equipment and with the relatively small front grill openings should also tell you that GVW vs. frontal area is not a factor in the case of the Liberty CRD. He is simply not overheating, no matter how hard he is playing with it off road in hot weather at low speeds.

Another member on LOSTJEEPS.com who is really into using electric cooling fans has mentioned to me that there is an O.E. electric cooling fan application known as the "Hot Rodder's Secret" that fits quite nicely in the Liberty CRD. That application is apparently for the 90's era Ford Taurus SHO sedans and the Crown Victoria Police Interceptors. Apparently these fans are single electric fan assemblies that pull around 5000 CFM, and are quite inexpensive to purchase. If this is true, it would appear that we have the solution we are looking for in a heavy-duty electric cooling fan that can closely match what the O.E. mechanical fan pulls in CFM, but still has all of the efficiencies of being electric. However, I am unsure of what kind of electrical current a fan like that will require to run it.

I have to agree that an electric fan is going to be better than a mechanical fan in many cases. Sure, mechanical fans will push more air overall, but only at peak engine RPM. My particular overheating issue(I started this thread) is occurring at 2000rpms while climbing I-80 at 70mph. If I am only spinning my stock fan at 2000 rpm's, and it apparently moves 5000 CFM at 4000 rpm, then that means I am only moving ~2500 CFM. An electric fan like the FFD3600 can move 3600 CFM regardless of the engine RPM so basically anywhere below 3000 rpms it will be working as well or better than the mechanical fan. Since most us are not driving around all day above 3000 rpm's I dont see how the mechanical fan would be superior except in the most extreme situations.

Plus, my F150 ecoboost has electric fans and does just fine. That thing weighs 6500 lbs and has a GCWR of 17100 lbs and doesnt need a mechanical fan.

_________________
2006 CRD - GTB2056 turbo by Dieselguy86, Eco Trans Tune, Lift Pump, Week's, HDS Tstat, Racor Filter, ARP's, OME 790's+Top Plate, JBA 2.5", JBA UCA, Moab's+265/75R16, ARB Bull Bar, 4.10's, TrueTracs

That actually is not bad at all... can you make it look good? I was under the impression that cutting louvers was a difficult thing to do.

However, please correct me if I am wrong, but have you already performed the following on your CRD cooling system in order to rectify its various faults? If I have missed anything please list all of your upgrades....

1) Installed an in-line thermostat into the upper radiator hose.... the "195 degree thermostat" your signature describes.

2) Gutted the O.E. thermostat assembly to remove the offending O.E. thermostat valve, and then JB welded the housing back together.

I can only assume you did #2 to avoid the potential hazard that can occur when an in-line thermostat valve is installed on a CRD engine that has the O.E. housing intact. If the O.E. main thermostat valve controlling coolant flow circuit to the radiator fails open, the cooling circuit bypass valve fails closed by default. If an in-line thermostat valve is installed in the upper radiator hose in conjunction with an O.E. thermostat assembly where the bypass valve inside has failed closed, you have little or no coolant circulating in the engine's water jackets during warm-up because there is no coolant flow through either the main radiator circuit OR the bypass circuit. The result of that scenario is an engine that forms hot spots around the exhaust ports of the engine, with the potential result being that the cylinder head warps or cracks and head gasket failures.

A) The relationship between the Fan's RPM and it's airflow, especially given the restriction of the radiator and the AC condenser is NOT linear.
B) The relationship between your engine rpms and your fan rpms is not linear. Even at "Full Lockup" the fan clutch still "slips". So at 4000 RPM it will be slipping a lot more than at 2000 rpms.

So basically, if your stock fan is rated for 5000 CFM (At 4000 RPM as you say it is), then it's going to be more like 80% of that at 2000 rpms.... which is 3200 CFM....

Not to mention....

How much HP and torque are you making?

The GDE hot tune, at 2,000 rpms, the most you could be making would be like 360? 380? ft lbs?

HP = Torque @ rpm / 5252

so at 2000 RPM at 380 ft lbs is 145 HP.....


So if you had a GDE hot tune, and even if it took maximum engine torque to hold you at 2,000 rpms.... you only have to worry about cooling 145HP worth of heat.. at the VERY MOST...

And with 70 MPH worth of airflow over the radiator, I can't imagine you needing much additional "fan power" to keep your engine cool.


not to mention



Your running your engine 30F hotter than stock?

That would make your stock radiator and fan even MORE efficient....

That means there is a greater possible difference in temperature, and your radiator and fan can cool away even more BTU's given the same air flow.



In my experience, it's when you're pulling a lot of weight up big hills at like 40 MPH at like 3200 rpms for sustained periods of time that lack of fan flow starts to become an issue with these CRD's.....


That's when you find out if your stock fan clutch it working or not, etc.....






That's what they rate it for, yes, but will it do that in a restrictive environment like the front end of a liberty?




It's true, a lot of the newer vehicles, including trucks have switched to electric fans, But that F150 also has way more frontal area, and 2 electric fans.

Makes a big difference.

And they also run hotter thermostats from the factory, which makes their cooling systems more efficient given the same rad size / frontal area / fan CFM.

I believe it's 176 vs 188....

which may not seem like much, but it's the difference vs the ambient air...

so if it's 110 degrees out, the 188 degree ford gets 78 degrees of delta between the engine, the radiator and the ambient air
but if it's 110 degrees out, the 176 degree liberty only get 66 degrees of delta between the engine, the radiator and the ambient air

That means that all things being equal, the fords cooling system is 18% more efficient at dumping engine heat into the ambient air (with those numbers anyway )







No, the fan clutch has no idea what temperature the water inside of the engine is, all it knows is how hot the air is inside that fan shroud.

As the air inside the fan shroud gets hotter, it "locks up" more, that's it.

The fact that the coolant entering the radiator is hotter will make no difference, because there will be less coolant traveling through the radiator.

(the reason your engine is 30 degrees hotter is because your thermostat will be more restrictive causing less water to flow, that's how thermostats work, they reach a temperature / flow equilibrium)


Think of it this way.

You got a bathtub and an electric water heating element.

If you stick the electric heating element in the bathtub, the bathtub heats to 80 degrees.

in an hour it's 80 degrees, in 5 hours it's 80 degrees.

The bath water is dissipating the heat at the same rate the electric heating element is heating it.

Now instead of putting that heating element directly in the bath water, you instead put it in a pot of water that you pull out of the bathtub.

let's say that every 1 minute you empty the pot into the bath tub, mix the water around, re fill the pot and stick the heating element back in.


If you wait 1 minute, maybe the water in the pot gets to 90 degrees before you switch it out.
if you wait 2 minutes, maybe the water in the pot gets to 120 degrees before you switch it out.


Either way, the bath water isn't going to get anywhere above the original 80 degrees that you got by sticking the heating element directly in the bath water. (because you are still using the exact same amount of source heat energy to heat the water)


You may be putting in 1 pots worth of water at higher and higher temperatures, but you will be doing it less and less often.


In fact, as you let the pot get hotter and hotter, the bath with actually get colder and colder because of all the heat lost by the pot itself.

If your engine is 30F hotter, the air cooling effect of the engine itself will dissipate even more BTUs...



Sooo, I don't know what to tell you.

I would put a temp sensor in your lower rad hose and see what's actually going on before I made any decisions.

if your engine temp is like 220, and your lower rad hose is like 150 or less, then I would say you have a water flow issue....

But if your engine temp is like 220 and your lower rad hose is like 190 or higher, then I would say you have a fan CFM issue
(but I can't imagine how @ 2000 rpms @ 70 mph)

This is exactly the problem mass-hole is having.
He's climbing a mountain at 70mph in 5th gear, 2000 rpm.
Its been a hot summer and he's got the AC-on.
Its a high load but still probably not at max torque.
The cooling system cant keep up with the load and heat generated.
2000 rpm should provide enough coolant flow.
And 70 mph provides enough airflow with or without any fan.

So, why is his engine getting too hot?
a. the high altitude and lower air density
b. aditional heat created by the AC condensor and intercooler which are both in front of the radiator
c. high engine load trying to climb the mountain at 70mph

Possible solutions:
a. install a radiator with more surface area to transfer away more heat, or install a fan that can pull more air through the radiator stack
b. turn off the AC
c. slow down

Another possible solution is to install a cooler thermostat. This would provide a bit more headroom for the rise in temperature so that a he crests the top of the hill the temp is only at 215 instead of 220. (or whatever it actually is)
He could also experiment by running no thermostat at all. I've done it.
What I found was that if all the conditions are right it doesn't matter what temp thermostat you are using, coolant temps can still get up to 220 or above.
All you are really left with is either:
a. increase airflow through the stack
b. reduce heat load within the stack



I put a temp sensor on my cylinder head. Its not the best setup, just pressed against the side of the head.
Here is what I have found:
Fully warmed up at idle, the cylinder head temp sensor is within 2-5 deg cooler than coolant temp.
Driving at 70mph (2000rpm), head temp is 15-20 deg cooler than coolant temps. This was on flat highway, light engine load.
At lower rpms and speeds head temp is 5-10 cooler than coolant temps. Again, flat roads and light load.
Naturally, under high acceleration and high load, the head temp goes up a little. But quickly comes back down once I'm at a steady speed.

This tells me that the coolant is doing a good job of transferring heat away from the cylinder head. At higher rpm there is greater coolant flow and better heat transfer. At lower rpm there is less coolant flow and less heat transfer.

_________________
U.S. Army Retired

That will tell you what temperature your cylinder head is, but it won't tell you how each portion of your cooling system is working.

What does the cooling system do? It gets rid of excessive engine heat. (and keeps the engine at a consistent temperature)

How does the cooling system do it? By transferring the heat from the engine to the ambient air.

What are the steps involved in transferring the engine heat to the ambient air?


1. Transferring the heat from the Engine to the Radiator.
2. Transferring the heat from the Radiator to the ambient air.

Those are 2 basically independent systems, but the efficiency of one effects the efficiency of the other.

If you know the engine temperature, and you know the ambient air temperature, then knowing the lower rad hose temperature specifically will allow you to do the math and determine the efficiency of both system 1 and system 2.

Then you can figure out which system needs improvement.

So if your numbers are like:

Engine 220
Ambient Air 110
Lower Rad hose 190

Your radiator is off by 80 degrees and your cooling system is off by 30 degrees. I would say that your limiting factor with those numbers is by far the radiator to ambient air. Install a better fan!

But if your numbers are like

Engine 220
Ambient air 110
Lower Rad hose 160

Your radiator is off by 50 degrees, but your coolant flow system is off by a whopping 60 degrees. Something is wrong with your coolant flow system. Water pump? T-stat? Coolant flow restriction through rad?

Remember, it's a hell of a lot easier to move heat with water than it is with air, so I would expect a much smaller difference between the lower rad hose and the engine than with the lower rad hose and the ambient air (assuming these numbers are specifically from the moment he is having the over-heating issue @ 70 MPH)

My point was, it doesn't seem to be a coolant flow problem.

And based on the numbers Geordi got with his temp gun, looks like it could be an airflow problem.
Another possibility is that some of the tubes in the lower part of the radiator are clogged. This would reduce the effective size of the radiator.
One thing I don't like about the CRD radiator is that the outlet on the passenger side is not at the bottom. Its almost halfway up. So when solids fall out of suspension, they settle at the bottom and don't get flushed through.

_________________
U.S. Army Retired

Well apparently 145 HP is too much for the cooling system at 6500', at least with a bad fan clutch/no fan. Again, how much time do you really spend above 3000 rpm, or even 2500. This jeep makes all but a few HP by 2800 RPM's anyways so unless you need the space to downshift to a lower gear for towing, the remaining 1200rpms doesnt buy you much. Plus, at 2000 rpms the water pump is not moving as much, so per rotation of the water pump you are burning just as much fuel as you would be at 4000 rpm making 200 hp. The only difference is your torque as fallen off because of the piston speed.

In my case, since I dont need every single HP the engine produces, a downshift may benefit me as I would get the extra flow from the water pump but burn less fuel per piston stoke to make the HP I need(more RPM, less torque). If youre towing and do need every HP, then you will likely be in the same boat as I am at 2000 rpm.



The thermostat temperature really doesnt matter other than to possibly delay the inevitable. As you have said(i think), heat in must equal heat out so the coolant is going to stabilize at whatever temperature it needs too to have a big enough delta T against the incoming cooling air, regardless of what temp the tstat opens. If you had the same jeep as mine but with a 176F T-stat, it would still heat up to 210+ to shed the heat. A cooler tstat will only delay the inevitable by a minute or so but I am talking about climibng 3000 ft in 12 miles and despite the high specific heat of water, it really doesnt take that long to heat it up in the engine. I see a degree every few seconds under load.



This could be true, but I do know that I didnt have issues with the hot tune in New Hampshire towing my buddies 5000 lb wakeboat. My fan has not worked since I bought the jeep 3 years ago. I believe my issue is related to air density at altitude and the fact that I have removed all limiters in my tune. So I am basically trying to cool the 145HP with 20% less mass flow than at sea level. I understand that one answer is to dial the tune back, which I will until I get a solution worked out, but ultimately I will have a new turbo running more boost and more fuel and will just have the same issue so I should just solve the issue now.



I dont know what the stock fan is truely rated for when its in the engine bay. I believe GDE was the one who stated somewhere around 5000 CFM but I dont know if thats at 0 in/h2O or what. It could be a total apples to orange comparison. I assume 5000 is at 0 static pressure though.




I guess you are right but at least part of the air flow going trhough the radiator will have to be hotter because it is interacting with 203F coolant. Maybe the overall heat exchange is the same because the delta T across the radiator is now larger due to the higher inlet temps and lower flow rates, but some part of the radiator is going to have to remain hotter than before and airflow stays the same.

I was never looking for an answer to my cooling issues. I started this thread simply to ask if the increase in coolant temp was causing peoples Hayden clutched to engage too soon so I wasnt driving around with the fan roaring away. I understand why I am having issues, I am pushing my jeep harder than most at higher elevation than most. For all I know a fan wont make a difference regardless of mechanical or electric. I did buy the hayden clutch anyways to try and hold me over until I can figure out a better solution. Plus, ambient temperatures are starting to drop and by september will probably be low enough that this wont even be an issue.

Like I said, ultimately this jeep is going to get pushed even farther than it currently is so I am going to have to do something. Part of my upgrades will be a bigger and/or better CAC, but I am thinking one that doesnt block the entire radiator flow path could be a good thing as it will allow a greater delta T and possibly more air flow on at least part of the radiator. An electric fan would allow me to remove the A/C fan and give me ALOT of space in front of the radiator and condenser for a nice, thick CAC core.

_________________
2006 CRD - GTB2056 turbo by Dieselguy86, Eco Trans Tune, Lift Pump, Week's, HDS Tstat, Racor Filter, ARP's, OME 790's+Top Plate, JBA 2.5", JBA UCA, Moab's+265/75R16, ARB Bull Bar, 4.10's, TrueTracs

flash7210:

Are you ignoring this posted response?

You are overheating your engine in some circumstances, and I am trying to discover what you have done with your cooling system to see if that is part of the problem... please respond.

Never truely overheated.
Just got hotter than I like. 225 max.
Only happened like 3 times in the last 2 years.

_________________
U.S. Army Retired

I got the Hayden installed yesterday and had a decently warm 88F day today. I did a few pulls up some grades and the new clutch did make a big difference. Even with the A/C at full blast I could only get the temp gauge a hair past dead center at full load and 5th gear locked. Just for giggles, I hit O/D off to get the RPM's up and fan spinning faster and the gauge plummeted back to 203F.

_________________
2006 CRD - GTB2056 turbo by Dieselguy86, Eco Trans Tune, Lift Pump, Week's, HDS Tstat, Racor Filter, ARP's, OME 790's+Top Plate, JBA 2.5", JBA UCA, Moab's+265/75R16, ARB Bull Bar, 4.10's, TrueTracs