Tried to keep track of a number of things on a trip this last weekend from Denver to Moab.

Speedometer error - at highway speeds, the speedometer reads about 3 mph high, all the work area radar displays agreed.
Odometer error - about 1.5%. On a long stretch, I lost 1 mile in 75 actually traveled.

Toyo Open Country tires size 225/75/16, 40 psi.

Fuel mileage basically sucked. I partly attribute this to the large car top carrier and 75mph. Got about 23mpg there without the ORM, once there I disconnected the MAF and got 25 mpg on the way back. I will have to do the next trip without the carrier to see how that affects things.

I had one issue and maybe you with CRD experience can help: Hauling out of Denver up to Genesee, 70F, OD active up the hill, the temperature gauge rose to 3/4 before I backed off. Cut off AC and dropped to 50 mph cooled it back off. Took it easy up the hills the rest of the way and had no more temperature issues. But once there, I was camping up on Sand Flats road, and the short but steep uphill stretch and the temperature shot up again. I'm thinking it was partly due to the low rpm and low airflow through the radiator as the AC was off and the temperature was only about 60F. On the way back, on the long stretches of uphill, I simply turned off the OD and had ZERO issues, even flying up Vail pass and the Eisenhower tunnel approach at 65.

I am not sure my vehicle has a cooling issue or not. It seems like the pusher fan is slow to turn on -- when it does come on the temperature drops back to normal. There are also a lot of small rocks imbedded in the AC condensor and maybe the airflow is not what it should. Has anyone heard of the CRD thermostat momentarily sticking? Just another thought I had. I am quite concerned with this. The vehicle I replaced with the CRD was a Subaru that had a thermostat stick shut, and the overheating destroyed the engine. Also Mercedes had head cracking issues in their first run with aluminum headed diesels, if they even slightly overheated, they would start drinking copious amounts of coolant and pressurize the radiator.

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'05 Liberty CRD B100, SEGR - SOLD

'01 Beetle TDi B100, EGR delete
'83 Mercedes 240D B100, no EGR

--- SEGR Builder ---

No comment? Sorry, didn't do the hot tub...this time...

I've heard the ECM controls the temperature gauge, anyone had issues with its accuracy? If the gauge is accurate and the temperature went to the 3/4 mark, can this have caused any damage? The 3year/36k warranty is running out and if I have an issue, I want to get it worked.

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'05 Liberty CRD B100, SEGR - SOLD

'01 Beetle TDi B100, EGR delete
'83 Mercedes 240D B100, no EGR

--- SEGR Builder ---

I have seen the temp climb, ussually when towing or when the air flow is disrupted like when following a truck too closely Backing off and/or disengaging overdrive seems to make it drop back to normal.

Definitely don't want it to overheat. I keep a close eye on it. I have a scanguage and have noticed that my CRD's temp gauge doesn't always track the temp as reported by the scanguage. I think I trust the scanguage more than the dash.

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2005 CRD "Ol' Blue"
Red Ryder carbine-action, two hundred shot range model air rifle with a compass in the stock and this thing which tells time.
My build page- RL Komodo Rear and TJM Front Bumper, armored, lifted, JBA Steel D30, 4.10s and ARB air lockers.

Did you do the TSB for this. It has worked for some, not for others but it is worth a shot.

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2005 Black CRD Sport
All J CRD Frankenlift with 500 fronts, Boulderbars, and Superskid
Kilby Gas Skid
Yukon Rear Axles
265/75 16 TrXus M/T's and Bridgestone Revo's
Fumoto Valve
Aero Turbine 2525
Rock Lizard Komodo Bumper
Sundance Custom's Front Bumper

What's the TSB?

It makes sense to me that dropping out of O/D will help cool, because the higher RPM will not require as much boost, reducing the heat in the intercooler, which helps the radiator cool. I wonder why, with all the sophistication of the ECM, it cannot recognize this and drop out the O/D if the temperature setpoint rises. I fortunately noticed the needle rise before it was too late, unlike my poor Subaru last year. The needle buried itself into the stop -- it had never had a cooling problem up that point and it was all over in 5 minutes.

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'05 Liberty CRD B100, SEGR - SOLD

'01 Beetle TDi B100, EGR delete
'83 Mercedes 240D B100, no EGR

--- SEGR Builder ---

I don't think it was a published TSB just one of those for the service writer to check given a specific list of customer complaints. Sometimes the sensor is reporting higher than actual temp. Some who have an alternate way to read the coolant temperature have found it to be OK. May be worse on '05's.

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Dave

'06 CRD Limited, Lt. Khaki, MOPAR Slush Mats/Skids, DrawTite Front Hitch, Mag Lite, Yakima Bars, Thule Bike Rack, Fumoto, ORM, 245/70 Revo 2

Wish list: Lift, Boulder Bars, Something Bigger in the Front and Back, More Lights

There is also that tranny. Disabling OD might have had the lock up on, while without it you may have been fluid coupled. Having the lockup on significantly reduces heat load on the tranny. That darned tranny heat exchanger is up front next to the radiator and everything else. While air blowing into it helps, you can bet it loads the whole engine bay down with the heat it radiates when it sheds the tranny heat.

You might want to check the fan clutch. They are mechanical clutches that regulate the air speed, sometimes they go out and some CRD's had a bad batch of them to begin with. If that fan is not rotating at the right speed-- you will overheat more.

I bought in March 05 and by May I began to experience overheating along with a bunch of other CRD owners. Long grades caused overheating consistently as spring temperatures rose above 80. The first "cure" was the thermastatically controlled fan clutch. There were a bunch of bad ones in the early 05's. My dealer verified it was faulty and replaced it under warranty.

I questioned whether that was really the problem, since I was overheating at high speed, and, indeed, it had no impact on my problem. However, this could be your problem when you experience overheating at slow speed offroad.

Ultimately, the fix was recalibration of the gauge. A lot of owners had it performed.

Since then my guage will only occasionally rise above normal, and then only a little, under the most extreme heat and/or grade conditions. Pulled a trailer across I-80 in 100 degrees and only slight problem approaching 70mph. Bring the RPM back down to 2000 at about 65mph still in OD: no problem. In hot conditions and when pulling a trailer i experience a rise in temp on the I70 stretch headed toward Genessee. But temp goes down to normal in seconds if I reduce RPM to 2000.

Be aware if you take it in and they hook up to it YOU WILL get F37 if you don't already have it alomg with upgraded ECM and BCM flashes. Avoid it if you can. Once hooked up online STAR takes over and the local techs have no control. At least that's what I'm told.

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Atlantic Blue 06 CRD Limited (his)
Joined by a 2000 XJ Classic (hers)