Ah, I see. When I put mine back together I was able to source everything but the shroud. So been running it without ever since with no probs. But I don't tow (have a Cummins for that) or drive in the desert or mountains either.

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2005 Liberty CRD, with 135,XXX miles. Rockers, exhaust valves, Provent, EGR block & butterfly delete & V6 air box at 100K

1998 XJ 4.0L, stock with 130,XXX miles

First Jeep: 1962 Willys CJ-3B

I am pretty sure I'd be fine during the winter here without the mechanical fan, but come June it'll be 100F+ for weeks on end, and cars need all the cooling they can get, especially if the world gets back to normal and I get to "enjoy" a trafficky commute in that weather!

Mishimoto bombed out for me - disappointing customer service this time around.

That cut-to-fit Summit option is still on the table. The one downside there is that the "universal" market is largely limited to 16" fans, and that seems like an under-utilization of a 20+" square radiator. So I've started looking at OE options, where bigger fans exist.

The JK Wrangler has a pretty kickass 19.xx" fan. The shroud is quite a bit larger than the KJ's radiator, but I think the critical dimensions are actually workable And is solvable with a little trimming. Unfortunately, it's a $300 experiment to run. Kinda like the idea of sticking with legit Mopar OE, though. #68143894AB

The fan for a V8 GM Alphas (ATS-V, Camaro) is also about the right size. And also a $300 experiment. GM #84100128

I may go hit up the local Jeep & Cadillac dismantlers and see if they have parts from a wrecked car I can measure. I figure either of these fans are more than capable of keeping a relatively low-output engine cool under the worst circumstances, so even though they're pricey I'm liking this direction.

So, this radiator fan project is either coming together, or falling apart. I'm trying to source a JK or Alpha radiator fan to test fit... not having much luck locally, next stop is probably the internet.

But I learned both of these fans expect PWM control... which isn't great, but ultimately isn't surprising. After poking around, though, I think I've found a relatively inexpensive solution that *also* obviates the need for a dedicated sensor:

https://ls1tech.com/forums/forced-induc ... s-diy.html

To make this work, I'd just need to verify the factory ECT sensor is NTC (it almost certainly is!) and then find its beta.

I've been dying to have a legitimate reason to learn something about Arduino but I can never seem to force myself to learn something that doesn't have an immediate, practical application. Maybe this is that practical application that helps me get my feet wet.

I've been having a leak out the back of my motor. Did a pressure test when cold it was fine no leak. After it warms up I have oil and cool leaking out the back. When I have time I'm goimg to pull mine out and do a total engine rebuild.

Sent from my SM-G960U1 using Tapatalk

I made the unfortunate realization that every thing left to be installed on the Jeep is part of a jigsaw puzzle that starts with the cooling core, so basically I'm at a standstill until I sort out the fan. *Still* haven't gotten a reply from ffdynamics, so I'm definitely not interested in pursuing that option. DIY it is. Well, DIY with some help from people smarter than I am, anyway.

First step - find a fan that fits. I *plowed* through aftermarket fans on other cars and never achieved anything approaching factory reliability, so the key for me is finding a fan from some other car that fits. TBH, I didn't look that hard. I had some good options, couldn't find any other them locally, and ended up calling a friend at the local Saab-Volvo-BMW dismantler and he let me look through what they had. Choice? Fan from an F30 (2011-2019) 3-series.



This is a pretty gigantic, 600w fan. It used in 3.0l twin turbo sixes, so I think it will be fine keeping a piddly little diesel cool. The shroud should require very minimal modification to fit perfectly. Both a pro and a con, this is a brushless, PWM-controlled fan assembly. Pro because it's brushless (more efficient) and PWM (potentially quieter, less electrical strain) and Con because it's more work to make it work properly. My end goal is to intercept the temperature from the existing coolant temp sensor and control the fan using that data. Assuming I can make that work, I think this is a hell of a solution.

Have you looked at this company? They build custom sizes...
https://powercoolsystems.com/custom-racing-radiators/

_________________
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

So if you do intercept the temp sensor will you let it run a tad warmer as they say it needs to do or did you upgrade to the aftermarket higher temp thermostat already?

_________________
2005 Liberty CRD, with 135,XXX miles. Rockers, exhaust valves, Provent, EGR block & butterfly delete & V6 air box at 100K

1998 XJ 4.0L, stock with 130,XXX miles

First Jeep: 1962 Willys CJ-3B

I did look at a couple custom radiator options, even considered petitioning the CRD crowd here for an order of 20 so that Champion would build something. In the end, I decided the cooling capability of the stock system really wasn't in question, I'm really just trying to fix an annoyance (difficult access) and maybe earn a few extra mpgs by not powering a mechanical fan all the time. I think the BMW fan will go great with the stock radiator, so mission accomplished.

I'm not too worried about the running temps - it's a new stock thermostat. It's pretty warm here most of the time, so cars running cold aren't generally a problem.

I am not certain about what *peak* temp should be, though, so that's a real point for discussion. I'll be reading water temp directly so that should be a bit more accurate than how the clutch works. Generally speaking you want an engine to stay in a pretty narrow range of operation to reduce thermal stresses; IIRC a common rule is the fan should come on 10-15F above the thermostat. I'm not sure where the Jeep should be... 195F? 205F? I don't want to cool unnecessarily, but I also don't want to put the head/gasket at risk with constant heating/cooling cycles.

A nice thing about this PWM control is that I should have multiple fan speeds at my disposal, not unlike how the stock clutch works! I' thinking I should probably have a "never hotter than" temp for max speed and work backwards from there. Anyone have a WAG for what that temp should be?

A preemptive ability would be good. So when the temp starts to rise quick the fan comes on to stop it going too high. In process control we call it derivative action.
I would probably want max fan on by 205F on the way up & fan off or low speed at 200F on the way down. You are monitoring the hot coolant temp not the return cool temp.
When you are getting hot, there is a lag between the engine temp getting very hot in places & the coolant temp. The oil temp also would be a good indicator of how much heat is being generated.

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Australian KJ CRD 2006

There are electric fan controllers offered by companies like Flex-A-Lite and FFDynamics than can set the fan turn-on temperature and the fan turn-off temperature. You can achieve steadier engine temperatures with the correct settings.

You can also achieve the temperatures you want with a thermostat assembly that offers more than one opening temperature for the thermostat valve inside of it. This is one of the reasons why I chose the Hemi thermostat valve for the HDS Model 001 as the Hemi thermostat valve is offered in 180, 190, and 203 degree opening temperatures.

There is also something else to consider... A larger gateway - essentially, a larger thermostat valve - typically has a longer stroke to work with and therefore controls temperatures more precisely. A larger valve than O.E. has a larger capacity to flow coolant because they were designed for larger cooling systems to control heat on larger displacement engines that create more heat. A larger valve than O.E. specifications therefore would reach a fully stroked open position considerably less often even under very heavy demand situations, like towing in hot weather.

This is another reason why the Hemi engine thermostat valve was chosen for the Model 001.... it is perhaps the largest thermostat valve in the automotive industry. It's increased capacity to flow coolant makes it the best choice for CRD engines that have been modified to produce more power and/or when the engine is being used in extreme driving conditions.

I have a customer in the Florida panhandle who converted his Liberty CRD to be a dedicated rock crawler and mud bogger. When he installed his Model 001 and also installed a digital engine temperature readout, he reported back to me that he achieved rock steady 203 degree engine temperatures no matter how hard he worked his CRD engine.

The Model 001 also offers threaded accessory ports right where they need to be to install temperature sending units to run accurate engine temperature gauges and electric fan controllers.

Appreciate that, but all the pieces are sorted at this point - I'm just not sure what "good temperatures" for the engine are. I obviously don't want to bake anything, but I also don't want the fan running unnecessarily. It will be controlled with PWM, so it will "phase in" rather than jumping from off to full blast. What I need to discover is a temperature at which the fan starts up at low speed, and then a maximum temperature which causes the fan to ramp up to full speed. Based on the stock thermostat temperature, I'm thinking 195-205 is that range. That should keep thermal stresses low, but also allow the fan to remain idle most of that time. The fan will be controlled by the factory ECT sensor, so I don't need to worry about additional sensors or switches.

I have dual Westach gauges in my Cummins and monitor engine oil temp in addition to coolant and tranny.

_________________
2005 Liberty CRD, with 135,XXX miles. Rockers, exhaust valves, Provent, EGR block & butterfly delete & V6 air box at 100K

1998 XJ 4.0L, stock with 130,XXX miles

First Jeep: 1962 Willys CJ-3B

Yeah, the placement of the factory ECT sensor is a little unfortunate in that sense, since it monitors outlet temp rather than at the point of heat generation, but I suppose if it's adequate to control fuel it's probably fine for the fan. Not that it's apples to apples, but I have three sensors on my XR4Ti and can switch between them at the gauge - there can be a 10-15F variance from the center of the head to the thermostat housing just a few inches away, and that delta peaks *right* after boost maxes out (25psi) and stays wide for a few seconds. Eventually heat levels out and everything is just hot.

205 was the number that stuck in my head, so if it sticks in yours too it's good enough place to start. I'll set up up for 195F on/205F max to start and see where that gets me. My hope is that a big fan running at <100% will keep the engine at ~200F without having to resort to high speed frequently.

What would be interesting would be to know the actual metal temperature of the head in several locations since normally metal temperature will always be higher than the coolant temperature cooling it. Oil temperature is important, but it won't tell you much about the cylinder head status, it is more important for the bottom end of the engine where all the bearing loading takes place.
If I remember correctly, the HDS thermostat comes with a 195 or 203 deg. F thermostat unless ordered differently, so 210 would be a good temperature point to start fan cooling.

_________________
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

I'd be interest to know where a CRD normally spends most of its time... Moderate ambient temps at moderate speeds with moderate load. That would probably be a good indicator of where the fan should be set... That temp plus 10-15F. Do you know offhand when the stock electric fans kicks in? I'm sure it's in the FSM... I just never entirely trust that.

Not in the FSM, I looked. God what I would give for a detailed logic control diagram for these vehicles, it could tell us all that we ever needed to know in a lot of areas....

_________________
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

The HEMI engine thermostats that fit in the HDS Model 001 are manufactured in the following temperatures... 203, 190, 180, and now even 160 degrees Fahrenheit. Virtually all of the Model 001 assemblies I ship out are already fitted with the hottest valve available... the 203 degree valve.

TURBO-DIESEL-FREAK - have you observed how the electric fan behaves when coupled with your 203F thermostat? Have you monitored OBD2 ECT data during normal operation?

The modified BMW fan fit marvelously:



There are hooks at the top which I preserved so it could slip over the radiator core (as designed):



I made a bracket to bolt to the bottom of the core and support the fan using its pegs:



It's quite solid in this way, but I do need to devise something to hold in place... as is, I'm sure a big bump would knock it loose. But this is an excellent start - whatever is left is minor details.

It looks right at home in the engine bay, and leaves nice clearance for dealing with the accessory belt .... tbh, this was my big motivation in solving this "problem" now... I just didn't want to wrestle with the viscous fan on reassembly!



IMO you really can't tell it wasn't meant to be here unless you look carefully.

I did go ahead and power it up using a cheapo signal generator I bought for testing a Saab fuel injection system....



With a 12v, 100Hz signal, the generator can control the fan's speed from very slow to full blast. If no signal is present, but power is, the fan "defaults" to full speed. I reused the BMW harness, which includes a mighty 70A relay, so at least on a temporary basis I can use a simple toggle switch to turn the relay on or off and make the fan run at full speed. That's good enough to at least start the engine... so it's back to reassembly tomorrow. The last detail is just some wiring to hook up a controller so the fan can work automatically instead of via toggle switch.

I still use the O.E. mechanical fan & clutch.

The LOSTJEEPS Members I would communicate with regarding this issue are Mountainman and PZKW108; I think both of them have electric fan set ups on their CRDs with the Model 001 thermostat assemblies they have purchased from me.