I've a 2005 CRD, and had noticed a certain overheating while towing a travel trailer with 60 square feet of frontal area, and 5,000 pounds GVW on hot days, while going up hill. Had it hit "H" and bong at me once, although it didn't seem to be all that hot when I threw open the hood.

Anyway, took it to the dealer, and they told me that there was a TSB, the guage was incorrectly calibrated, and they fixed that. Seemed reasonable to me, since, as I said, the engine didn't seem all that hot, really, and after all, it was only 85 ambient that day.

So anyway, I just finished towing that trailer 7,000+ miles across the country and back, and wanted to let everybody know what I discovered.

We took the northern route west across Rt 2, just south of the Canadian border. Climbing the mountains near Pittsburgh on our way north, with an ambient around 95, it got hot, and to keep it from hitting "H" I had to turn off the AC, slow to around 35 mph (scary in that traffic), and turn on the heater full blast. Not good. Had the power, could have gone much faster/safer, but I did manage to keep it from hitting "H" and bonging. Wasn't too worried about the rest of the westward trip, since I didn't anticipate much more in the way of 90+ weather, and indeed, didn't encounter any, although the engine did run warm at 75 degrees, 55 mph, with a 30 mph headwind across Montana.

Anticipating worse taking the southern route around Death Valley and across the rockies, where 100+ is to be expected, I decided to get something done about it while I was in Oregon. Dealer there determined that not only was the fan clutch not engaging soon enough, but the thermostat wasn't opening completely.

Now I had heard the fan clutch engage only a couple times on the trip, usually just about the time the guage edged right up near "H." New fan clutch caused it to engage when the guage was one click hotter than the 3/4 mark. Beyond that, dragging the trailer over the rockies, skirting Death Valley, with temps near 110 and sticking as close to traffic as needed at 60 to 65 mph, with the AC going full blast, the guage never again got above the second click above 3/4.

But I do have to tell you that the thermostat took the record high price for a thermostat for me. Previous holder was a 1969 BMW I used to own, and the reason the t'stat was so expensive is because it was a 2 stage unit that included a housing and water connections for both hot and cold to mix to regulate the water pump's INTAKE water temp. Turns out the Libby uses the same system, thus $160 for the thermostat. But it was worth every penny in that 110 degree heat.

I wanted to thank folks here for suggesting to me that I should have heard the fan clutch kick in. And for the suggestions about how to get it to stay in 4th gear instead of bouncing between 3rd and 5th all the time on the trip west.

Sounds like you ran upon a good dealer, glad they got your problem fixed.

Dave

If you were going 65 then I assume you were probably in 5th. Did you tow mostly in 5th on the flats? I tend to tow my 3,000 lb trailer in 4th @ 60 MPH, even accross flatlands. No problem even with th AC on and 104 to 110 outside (CA central valley) The only time I got concerned about heat was going up the Grapevine 104 outside, I turned off the AC, went up in 3rd (OD off) and even put the heater on a bit to keep the gague from getting too close to H. After discussions on this site and with Green Diesel I am less concerned about these heat issues although I will always be careful towing up really steep grades, it just makes sense to slow down and increase cooling for those few minutes of the trip on serious grades. Now if I were running near hot on the flat I would definitely start increasing cooling by getting additional coolers and anything I need to do.
The other thing that I am concerned about is the transmission overheating. I have never had the trans overheating light come on (H\has anyone?) so maybe I am OK there.

Glad your trip worked out well. I do not remember ever hearing the fan clutch come on but I assume it has. Is there a test I can do in my driveway to tell if it is working correctly? What led you to suspect the thermostat? A friend has changed his but on other vehicles if they lock open I just run cooler (locking closed is an obvious overheat, but you don't need Death Valley for that).

x2 yakers, runs cooler, use less fuel, I had a thread on this.

Edit: Here is the link

http://www.lostjeeps.com/forum/phpBB3/vie ... ht=#484204

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Certified Services Auto & Truck Repair

I don't know how the dealer determined the t'stat wasn't opening fully, but I do know that the fan clutch can be heard inside the vehicle. You don't want it engaging unless it is needed, as it loudly pulls a LOT of air through the radiator, and no doubt will kill your mileage if it was on too often. I heard it kick in (when it wasn't working right) once climbing a mountain just as I glanced down and the needle hit "H." I was doing probably 55 mph at the time, and there was no doubt what had happened. The other time I heard it we were going only about 10 miles an hour, climbing this driveway. It was really, really steep, and probably about 100 degrees, but the slow speed no doubt contributed by not putting air through the radiator. It was really loud when it kicked in, again just as the needle hit "H".

After the repair, I heard it several times on the highway. Again, there was no doubt that that was what the extra noise was, and the needle stopped climbing, and began to drop again, even in 100+ temps.

It should be noted that I never had the needle budge off the half-way mark regardless of the ambient temp in the 4 years I've owned this Jeep -- unless I was towing. I expected it to run hot while dragging that heavy parachute around. Which it had plenty of power to do, btw. I'm just glad we got the cooling system working correctly for that task.

naturist,

Many of us here would really appreciate it if you would contact the dealer service manager and ask what procedure they used to determine the thermostat was not fully opening.

Thanks in advance,

DOC

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2005 KJ CRD Ltd Detroit TrueTrac Bilsteins G2 GDE "HOT" ECU GDE TCM "Tow Tune" "euro" TC SEGR Weeks Elbow New HG at 130K ARPs Clean CAT aFe Filter Magnaflow Exhaust EHM Cumminos In-Tank Lift Pump Hayden Fan Clutch Nylon Fan VH Enabled with GDE lower shutoff point Recalibrated Temp Gauge Tekonsha Prodigy Sears P-1 ZDDP

It's easy. They did a credit check on naturist when he walked into the service department, and determined that his credit card bill was too small. They figured that he looked intelligent enough to realize that there are no such thing as "muffler bearings" or "over-bolsters", so knew that they would have to tell him that an actual part on the vehicle needed replacing. Since the Jeep was there for overheating a light bulb came on in the writer's head and the tech and service writer got together into a huddle and decided to split the $160.00 50/50. If poor naturist had paid attention to the replies in his first thread on the overheating issue, his wallet would be $160 fatter.

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Manure green 2005 CRD sport4x4, GDE Hot tune, Cat Gut, OE skids, Draw tight hitch, Duramax lift pump, 160K on multiple varieties of fuel, XM radio, Escort live with Redline, fog light mod, GPS, Icom IC7000 all band radio call sign KC9QPF, Grabber AT2s on Soft 8s, FIA grill blanket.

ROFL!

I did read the first thread, and spent a LOT of time on the drive out (at least 2500 miles worth) messing around at speeds between 55 and 60 and found that I could get it to stay in 4th if I set cruise on 57 (indicated) mph, and then made it shift into 3rd by taking the OD off, then turning OD back on and it would stop on the way up in 4th. And still it tended to get too hot. I was not looking forward to having to do that across the desert and over the rockies.

For what it is worth, back in my BMW days, I had occasion to replace those fancy thermostats on a couple cars. And I had long chats with the guys in the service department at the dealer. I did ALL my own work in those days, including rebuilding two BMW engines, one of 'em being hot-rodded with Weber carbs and high compression pistons and blueprinted. And I know that BMW thermostats did a two stage opening process, and could fail such as to only open partially. My recollection was that they would sometimes remove the t'stat, and drop it in a bucket of hot antifreeze to watch it open or fail to open. I doubt they did THAT with this one, but it is also possible that they did soak me for the t'stat. Between you and me, I am just glad that somewhere between the parts that got replaced, the problem got solved. I was, after all, 3,000 plus miles from home at that point.

Oh, and for what it is worth, they had to ship the new t'stat to LA for my daughter's mechanic to wrench in, so they only got to split the profit on sale of the t'stat, and I'll bet they had to split THAT with the dealer. That'd make it 3 ways on what, maybe $45?