Over Heating CRD?!

onthehunt · **Posted:** Sun Aug 17, 2008 9:44 pm

Since your egr is stuck open and you are experiencing over-heating maybe you should block it off or fix it. They add a considerable heat-load to your cooling system. Also consider not taking the aluminum head crd to 250 on a semi-regular basis.

KeighJeigh · **Posted:** Mon Aug 18, 2008 1:55 pm

onthehunt wrote:

Since your egr is stuck open and you are experiencing over-heating maybe you should block it off or fix it. They add a considerable heat-load to your cooling system. Also consider not taking the aluminum head crd to 250 on a semi-regular basis.

I just ordered a new EGR this morning. ($150 from Halls) I will install it before I install the SEGR. That way, if there are any problems, at least I know I'll have a working EGR that won't throw codes.
Believe me, I certainly do not want to take this thing up to 250 deg - from what I've read, that is way too hot. Every day I have the AC on and it is hot outside, it gets near that temp by the time I get to the top of my driveway; not a good thing.

New T-stat and sending unit on the way too as well as a Mr. Saikou CCV can. Once it's running I'll take it in and see if the stealer will replace the screeching alternator pulley. Hopefully, after all this, I can break a record and get passed the 3 month marker with nothing going wrong.

chrispitude · **Posted:** Mon Aug 18, 2008 9:59 pm

Best of luck, Chris. Please take pictures of your EGR install in case any of us are also forced to walk that path...

- Chris

KeighJeigh · **Posted:** Sat Aug 23, 2008 7:23 pm

POS still overheats. Exactly the same problem.

fastRob · **Posted:** Sat Aug 23, 2008 11:21 pm

KeighJeigh wrote:

POS still overheats. Exactly the same problem.

I read over this thread twice to see if I understood what you are going through.
You are tough. I admire tenacity. We all do.
Have you pulled the intercooler and looked inside? Is the exhaust flowing freely? Any airway restrictions?
I am thinking of secondary problems that might cause heat restrictions. Like bad ignition timing could in a gasser, Patooie!!
Is there anything that when on the incline of your driveway could rotate to block the flow of your coolant? Assuming overheating happens on inclines.
Thank you for the thermostat pictures.
We are in this together, you are not alone, even if you are, you know what I mean?

KeighJeigh · **Posted:** Fri Aug 29, 2008 9:42 pm

fastRob wrote:

KeighJeigh wrote:

POS still overheats. Exactly the same problem.

I read over this thread twice to see if I understood what you are going through.
You are tough. I admire tenacity. We all do.
Have you pulled the intercooler and looked inside? Is the exhaust flowing freely? Any airway restrictions?
I am thinking of secondary problems that might cause heat restrictions. Like bad ignition timing could in a gasser, Patooie!!
Is there anything that when on the incline of your driveway could rotate to block the flow of your coolant? Assuming overheating happens on inclines.
Thank you for the thermostat pictures.
We are in this together, you are not alone, even if you are, you know what I mean?

Thanks for the kind words. There's tenacity, and then there's not knowing the appropriate time to give up.

I actually had the pleasure of meeting one of our forum members who lives nearby. He offered to bring his 05 up the driveway for direct comparison to my 05 and my wife's 06 - which does not overheat. What we found was that our 05s had a fraction of the air blowing through their radiators than the 06 did. His 05 has had a couple of overheating issues as well but he doesn't stress it daily as I do climbing my driveway each day - that is why I can recreate the problem on a warm day with the AC on.

So, the problem appears to be the viscous fan clutch as that is what engages the mechanical fan depending upon temperature. Apparently there was a batch of 05 CRDs that had defective fan clutches. Some people have theorized that the reason some 05s get better MPGs is that the fan is not engaged as much so it doesn't rob as much horsepower. It would also make sense that dealers and others would rarely notice it because most people don't drive in the same conditions as I do: A slow drive up a steep series of hills followed by a very steep 7 minute crawl at 15 MPH. (I've never had a problem if driving over 25 MPH because the fan plays less of a role in cooling - even in really hot weather.) But, that is my driveway so the jeep sees those conditions daily.

I will remove the old clutch and compare next to the new clutch - perhaps run some comparison experiments on their kick-in temperature before I install. I'm fairly confident this the problem.

KeighJeigh · **Posted:** Fri Aug 29, 2008 9:44 pm

fastRob wrote:

KeighJeigh wrote:

POS still overheats. Exactly the same problem.

I read over this thread twice to see if I understood what you are going through.
You are tough. I admire tenacity. We all do.
Have you pulled the intercooler and looked inside? Is the exhaust flowing freely? Any airway restrictions?
I am thinking of secondary problems that might cause heat restrictions. Like bad ignition timing could in a gasser, Patooie!!
Is there anything that when on the incline of your driveway could rotate to block the flow of your coolant? Assuming overheating happens on inclines.
Thank you for the thermostat pictures.
We are in this together, you are not alone, even if you are, you know what I mean?

Thanks for the kind words. There's tenacity, and then there's not knowing the appropriate time to give up.

I actually had the pleasure of meeting one of our forum members who lives nearby. He offered to bring his 05 up the driveway for direct comparison to my 05 and my wife's 06 - which does not overheat. What we found was that our 05s had a fraction of the air blowing through their radiators than the 06 did. His 05 has had a couple of overheating issues as well but he doesn't stress it daily as I do climbing my driveway each day - that is why I can recreate the problem on a warm day with the AC on.

So, the problem appears to be the viscous fan clutch as that is what engages the mechanical fan depending upon temperature. Apparently there was a batch of 05 CRDs that had defective fan clutches. Some people have theorized that the reason some 05s get better MPGs is that the fan is not engaged as much so it doesn't rob as much horsepower. It would also make sense that dealers and others would rarely notice it because most people don't drive in the same conditions as I do: A slow drive up a steep series of hills followed by a very steep 7 minute crawl at 15 MPH. (I've never had a problem if driving over 25 MPH because the fan plays less of a role in cooling - even in really hot weather.) But, that is my driveway so the jeep sees those conditions daily.

I will remove the old clutch and compare next to the new clutch - perhaps run some comparison experiments on their kick-in temperature before I install. I'm fairly confident this the problem.
(But that will have to wait until I get over whatever nasty flu I picked up on Thursday evening....just in time for the long weekend....I just went for a trail bike ride with my wife and almost didn't make it back.)

DOC4444 · **Posted:** Fri Aug 29, 2008 11:37 pm

KJ,

Have you carefully compared the '05 and '06 fans themselves to see if the '06 has steeper blade angles and/or if the '05 blades are less rigid and may flatten out more than the '06 when engaged?

(My '05 fan clutch passes all the tests, but overheating towing in hot weather has been an issue.) Really looking forward to hearing what you find when you replace your clutch. Hope you get well soon.

Best Wishes,

DOC

Joe Romas · **Posted:** Sat Aug 30, 2008 7:53 am

What will be of interest to me and possibly others is any adverse changes in his fuel consumption from the added load of a working fan

BlackLibertyCRD · **Posted:** Sat Aug 30, 2008 9:43 am

I know I had my gauge go up to 3/4 going up a Mountain pass heading west at Ryegrass, WA
It was 98+ degrees and slow moving because of a truck fire (he didn't make it to the top) on the side of the road.

I don't know if the fan clutch kicked in but it cooled very quickly once I reach the top so I kept going. I was pulling 3,000 lbs v-nose trailer at the time. I do remember to shut off a/c to reduce the load when I noticed the gauge going up. The pass has signs up to tell drivers to do that.

Other times I had no problem with the same trailer loaded and a/c on since highway speed is kept up.

KeighJeigh · **Posted:** Sat Aug 30, 2008 6:48 pm

BlackLibertyCRD wrote:

I know I had my gauge go up to 3/4 going up a Mountain pass heading west at Ryegrass, WA
It was 98+ degrees and slow moving because of a truck fire (he didn't make it to the top) on the side of the road.
I don't know if the fan clutch kicked in but it cooled very quickly once I reach the top so I kept going. I was pulling 3,000 lbs v-nose trailer at the time. I do remember to shut off a/c to reduce the load when I noticed the gauge going up. The pass has signs up to tell drivers to do that.
Other times I had no problem with the same trailer loaded and a/c on since highway speed is kept up.

Ah yes, the famous Ryegrass Summit climb! The cause of many a seized engine and burned up VW buses. 10 steep miles of pedal to the metal - and mostly straight so people towing can go as fast as their engines will allow....which on that grade is not always very fast. Perfect place to test a vehicle for all sorts of things including cooling issues.

If your gauge was at 3/4 the fan should have been fully on....but you might have been going fast enough that it didn't really make much difference.

Still, I find it amazing that any car made in the past 30 years should need the AC turned off while climbing a steep grade in hot weather. Required engine cooling in varying conditions is a rather basic design parameter. My diesel F350 4x4 dually overloaded with an 11ft Fox camper pulling a trailer has NEVER overheated no matter how I have abused it. In fact, I have never seen the gauge budge off of center.

I wonder if it would be possible to add some auxiliary cooling capacity for these mules? Perhaps another really small radiator in front of the battery box. It could be plumbed into the main radiator and have it's own small electric fan that would cut in and begin to cool at a preset temp.

KeighJeigh · **Posted:** Sat Aug 30, 2008 6:50 pm

warp2diesel · **Posted:** Sat Aug 30, 2008 7:22 pm

Summit has all kinds of radiators that have thicker cores that will work.
Good radiator shops can put a thicker core between the two tanks and it will drop right in. I checked the tanks on my 06 and there is room for another row of tubes.
Try the Fan Fix GMCTD recommended first.

KeighJeigh · **Posted:** Sun Aug 31, 2008 5:57 pm

I was reading about hood louvers in another section of the forum as a way to help cool the interior of the engine compartment. Anyone have experience with them? Do they work?
A drawback for me is that I don't yet have a garage and it rains a lot here so I could potentially have water trickling onto the engine. That wouldn't be a big deal but in winter, the day's slushy rains often freeze at night....hmmmm. Maybe once I get a garage?
Louvers:
http://www.raceace.com/

Another hood product I saw was someone who adapted a Mustang hood scoop to the Libby hood which actually looked stylish since it is low profile.

ATXKJ · **Posted:** Sun Aug 31, 2008 6:17 pm

To test that - pull the foam strip off the back of the hood/firewall seal - it'll help air vent from under the hood
however it'll blow the hot air into your cabin air intake.

warp2diesel · **Posted:** Sun Aug 31, 2008 9:40 pm

drag. This will drop your MPG unless you want to open the louvers only when they are needed.
Perhaps this could be off set by putting an aerodynamic tail (not a vertical rudder) onto the spare tire. You could either go with the Knife tail like the Boeing 777 or MD DC9 or go with the tear drop tail like the Boeing 757, 767 and all of Airbus fleet. If you go with the tear drop tail, you could place the exit point for the exhaust where the plains vent the APU :idea:

I have seen some ORT pulling trailers with a very dull version of the Knife Tail to reduce aerodynamic drag.

retmil46 · **Posted:** Mon Sep 01, 2008 10:41 am

warp2diesel wrote:

drag. This will drop your MPG unless you want to open the louvers only when they are needed.
Perhaps this could be off set by putting an aerodynamic tail (not a vertical rudder) onto the spare tire. You could either go with the Knife tail like the Boeing 777 or MD DC9 or go with the tear drop tail like the Boeing 757, 767 and all of Airbus fleet. If you go with the tear drop tail, you could place the exit point for the exhaust where the plains vent the APU :idea:

I have seen some ORT pulling trailers with a very dull version of the Knife Tail to reduce aerodynamic drag.

You could also give Darby's Airtabs a try. Haven't had the chance to get any definitive results as far as MPG, but they do make the beast more stable in crosswinds and that rear window stays remarkably clean compared to what it was before.

KeighJeigh · **Posted:** Mon Sep 01, 2008 1:32 pm

warp2diesel wrote:

drag. This will drop your MPG unless you want to open the louvers only when they are needed.
Perhaps this could be off set by putting an aerodynamic tail (not a vertical rudder) onto the spare tire. You could either go with the Knife tail like the Boeing 777 or MD DC9 or go with the tear drop tail like the Boeing 757, 767 and all of Airbus fleet. If you go with the tear drop tail, you could place the exit point for the exhaust where the plains vent the APU :idea:

I have seen some ORT pulling trailers with a very dull version of the Knife Tail to reduce aerodynamic drag.

I believe this is one of our member's rigs - which the louver company is using in their add. How can these add more drag than the windshield wipers or lights or rack or brush guard or hood bra? They are only 1/4" high.

ATXKJ · **Posted:** Mon Sep 01, 2008 4:02 pm

that's tjkj2002 - you might pm him to ask about mileage - but his is terrible anyway - with the lift, mud tires, armor - I think he as running 13's in town (gasser)

personally I don't think exit vents will impact mileage - however the grill openings will - Darby & several other folks have blocked off grill openings during the winter. I wouldn't try that until you can drive up the driveway without overheating

KeighJeigh · **Posted:** Mon Sep 01, 2008 7:46 pm

The fan clutch is in. Now I'm just waiting for another warm day to test it.

Over Heating CRD?!

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