Overheating Software TSB - "Top $ for your CRD"

BKH · **Posted:** Sat Aug 18, 2007 12:56 pm

I had an interesting dealer experience this week. I had to post it, as it's so funny how times have changed with our CRDs and gas prices. I went to the dealer to have the TSB done for the temp gauge indicating engine overheating. It always happened when I would leave Denver and head up I-70 into the mountains for some Jeeping.

I picked up the CRD later that day and, to my surprise, the sales manager was waiting for me. He said, "You know, we'll give you top dollar for your diesel if you'd like to get into a new Jeep." Well, unless you can give me a Wrangler Unlimited Rubicon on an even trade, I don't think I'm parting with it anytime soon!

I found this really funny. A year ago, they'd look at me like I owned the "sensored word stepchild" of the Jeep brand. While service people sometimes still have that mentality, it was really interesting to see the sales folks scrambling to get a hold of my CRD. I talked to my friend who sold the Jeep to me (he's at another dealer who has a hideous service department, but great sales department). He told me that they've been told to grab any CRD they can if someone has an interest in trading one in on another vehicle. He said they've had two CRDs traded in over the last month. Both were sold within a week - and one even sold despite the fact that the fuel system warranty had been "flagged" (not canceled, just a warning put in the system) because the previous owner loaned it to a friend who filled it up with unleaded.

My how times change!

robert46123 · **Posted:** Mon Aug 20, 2007 8:48 am

What are the specifics on that TSB? For the first time ever I noticed my temp gauge creeping towards the red last week when towing in 100+ degree tempatures. It was the first time I ever noticed it going past it's normal position. TIA.

BKH · **Posted:** Mon Aug 20, 2007 11:15 am

That's what happened to me, but rather than towing, I had 3 other people and my German Shepherd in the CRD and we were going up I-70 into the mountains - a series of very steep climbs. All of a sudden, I noticed I was one "notch" from red on the temp gauge. My gut said to slow down a bit and turn off the a/c - but it was still in the 90s, which wasn't too fun inside the car. Within a minute, the gauge started going down. In two years of making that drive, this had never happened. Why now?

There's a TSB (sorry, don't have the #) about this exact problem. It's a software re-flash for the temperature gauge. I ran up the mountain this weekend - 90+ degrees, full a/c. No problems. It didn't take long to do this. My question, which they couldn't answer, was "why now?" Things have been great for two years. Why did this happen all of a sudden? Maybe someone on the board knows.

BTW, I think there's a thread on here about this TSB. That thread might have the TSB #.

danoid · **Posted:** Mon Aug 20, 2007 11:42 am

The TSB doesn't change the coolant temperature. It only tells the gauge to lie more and stay right in the middle.

chadhargis · **Posted:** Mon Aug 20, 2007 1:26 pm

I had the temp gauge get angry at me on Saturday. Towing up a hill, I got a warning chime and noticed the gauge was way over to the right. I looked at my scan gauge, and it read 210 degrees. That's hotter than normal, which runs about 180-190 degrees, but not anything dangerous.

BKH · **Posted:** Mon Aug 20, 2007 4:37 pm

If the TSB is tricking the gauge into lying about the true temp, then how do we know when the engine is really getting into trouble? Why had this never happened in two years of making the same drive in hot weather, but now just decided to go crazy? Am I really overheating now and don't know it because the gauge is lying?

danoid · **Posted:** Mon Aug 20, 2007 8:13 pm

Pre-TSB the gauge is still anything but linear. 160°-200° is about the midline for me. By 210° it's at 3/4, 220° 7/8. Around 237-240° you'll get a chime and power reduction. It's almost impossible to overheat the engine. If you keep pushing it, it will pull power (use less fuel) and create less heat until things cool off again.

I've hit the chime three times in 43k miles. Doing doughnuts, trailering in the mountains, and a slow speed switchback up a mountain that I was hurrying up. It's no big deal. Just let the engine idle to cool things off - do not shut it off right away. That cooks turbo bearings.

Post-TSB just keeps the gauge in the middle longer and probably pegs to the right over a smaller temperature range.

kjfishman · **Posted:** Mon Aug 20, 2007 8:22 pm

BKH wrote:

I had an interesting dealer experience this week. I had to post it, as it's so funny how times have changed with our CRDs and gas prices. I went to the dealer to have the TSB done for the temp gauge indicating engine overheating. It always happened when I would leave Denver and head up I-70 into the mountains for some Jeeping.

I picked up the CRD later that day and, to my surprise, the sales manager was waiting for me. He said, "You know, we'll give you top dollar for your diesel if you'd like to get into a new Jeep." Well, unless you can give me a Wrangler Unlimited Rubicon on an even trade, I don't think I'm parting with it anytime soon!

I found this really funny. A year ago, they'd look at me like I owned the "@$#% stepchild" of the Jeep brand. While service people sometimes still have that mentality, it was really interesting to see the sales folks scrambling to get a hold of my CRD. I talked to my friend who sold the Jeep to me (he's at another dealer who has a hideous service department, but great sales department). He told me that they've been told to grab any CRD they can if someone has an interest in trading one in on another vehicle. He said they've had two CRDs traded in over the last month. Both were sold within a week - and one even sold despite the fact that the fuel system warranty had been "flagged" (not canceled, just a warning put in the system) because the previous owner loaned it to a friend who filled it up with unleaded.

My how times change!

What dealer is it I will deliver it from Missouri for the right price.

GaCRD05 · **Posted:** Tue Aug 21, 2007 10:40 am

I've had similar problems with mine. It was over 100 degrees here in Atlanta and sitting in traffic not moving, mine hit about the 3/4 on the temp gauge. It gave me quite a scare, but never over heated. Glad to hear I'm not the only one having these issues. This forum is proving priceless.

nursecosmo · **Posted:** Tue Aug 21, 2007 9:23 pm

Pick up one of those temp gauge radiator caps from autozone and you can tell foe sure.

o8k · **Posted:** Wed Aug 22, 2007 1:17 am

mine is always hot, breaks 1/2 way point on almost every offroad trip i do out her in the AZ summer weather. but a cool day here is 105F my engine temp (via Scan Gauge) is always over 200F. and when crawling up a mountain dirt road w/ it being 105 out, ac blasting, and only doing 10mph, my CRD regularly sees 220F, so off goes the AC and sometimes on goes the heater for a bit and it quickly fades to 195F ish....

I had a brain storm on this and wanted to run it by everyone here. Anyone here heard of "Coolant Cavitation"?

A little known phenomina in some diesel engines where the coolant walls bubble from the heat and vibration of the diesel combustion cycle. The little bubbles cause a few things to happen:

1) bubbles prevent proper heat transfer for the coolant to do its job
2) bubbles actualy corrode and destroy the coolant paths erroding into the combustion area of the engine (engine basicly hosed at that point)

Some diesel manufacturers like FORD for the power joke, eh hem, sorry power stroke, have an addative that helps prevent the cavitation from damaging the engine and robbing cooling capacity. Ive heard diesels like cummins do not have this issue due to the proprietary design of the motor.

Just wondering if our little itallian job suffers from this cavitation issue, it would explain the overheating in situations where it would seem unlikely or inapropriate for overheating to occur. But i have no idea if this is a risk to the 2.8L CRD

ANY thoughts?

o8k

onthehunt · **Posted:** Wed Aug 22, 2007 8:25 pm

Liner cavitation only applies to engines that are wet-sleeved. Cummins b or isb series engines are parent bore engines and do not have wet-sleeves hence they have no cavitation. The crd engine is wet-sleeved and I do not know if the coolant contains sca's(an additive to prevent cavitation). Coolant has really changed in the last 5 years so it could have the new extended life coolant in it. Called "hoat" which really made sca's obsolete. No need to replenish them or moniter them .Just change the coolant on schedule. I will take some test strips home tonight and check the coolant. This was brought up a while back but I don't think it was ever really answered. Your cavitation theory is a little off also. Cavitation is caused by the up/down movement of the piston in the liner which causes the liner to deflect a tiny bit in the bore. When it deflects it creates an air bubble that compresses and pops when the liner comes back. This happens extemely fast and under high pressure. It creates errosion on the liner wall and can eventually poke through. It is not a good thing but your engine isn't toast if this happens. Just install a new liner( not a small job!) I don't think it has anything to do with the crd overheating in your case.

seferis · **Posted:** Sun Aug 26, 2007 5:09 pm

I had the same problem last week upgoing a steep mountain with 4 people in and the A/C on at 86 degrees outside temperature . At the top of the mountain the needle indicator reached the red line. and then when going down it returned to normal (middle).
I was annoyed and was about to go for service to the dealer when i read this post.
I hope that it is only a tsb problem.

onthehunt · **Posted:** Wed Aug 29, 2007 7:28 pm

Just tested the coolant. It has 1.6ppm of sca in it. Right where it's supposed to be.

jinstall · **Posted:** Thu Aug 30, 2007 5:54 am

I drive between 100-121 mph and it never goes past 1/2

seferis · **Posted:** Thu Aug 30, 2007 9:14 am

jinstall wrote:

I drive between 100-121 mph and it never goes past 1/2

this happens ascending steep hills and not on even horizontal roads

retmil46 · **Posted:** Thu Aug 30, 2007 11:02 am

danoid wrote:

Pre-TSB the gauge is still anything but linear. 160°-200° is about the midline for me. By 210° it's at 3/4, 220° 7/8. Around 237-240° you'll get a chime and power reduction. It's almost impossible to overheat the engine. If you keep pushing it, it will pull power (use less fuel) and create less heat until things cool off again.

I've hit the chime three times in 43k miles. Doing doughnuts, trailering in the mountains, and a slow speed switchback up a mountain that I was hurrying up. It's no big deal. Just let the engine idle to cool things off - do not shut it off right away. That cooks turbo bearings.

Post-TSB just keeps the gauge in the middle longer and probably pegs to the right over a smaller temperature range.

Agreed. One owner related to me privately that after having this TSB done, he watched coolant temp go from 180 to 210 and back down to 190 on his scan tool, and the needle on his coolant temp gauge never budged from dead center.

MB switched over to the same HOAT type antifreeze (Mopar 5/100, Motorcraft Premium Gold, Zerex G-05) back in the early 80's. It's what they spec on the '87 300D I have. Also, they still spec doing a cooling system flush and coolant changeout every two years, despite using HOAT coolant. And if I order a replacement surge tank for it, the new surge tank comes from the factory with an SCA additive pouch already in the tank.

If it's been a couple years or more, and the vehicle has seen some high heat situations, couldn't hurt anything to go ahead and do a cooling system flush and eliminate any potential problems.

Overheating Software TSB - "Top $ for your CRD"

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