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| 2005 CRD Temperature not consistent http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=71672 |
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| Author: | clehmann [ Sun Sep 16, 2012 8:23 pm ] |
| Post subject: | 2005 CRD Temperature not consistent |
Hi to all. This is my first post as I just picked up my KJ a few weeks ago. It's running great and I love it, but I'm being careful since it does have 115k miles on it and you never know what you're going to get (dealer used car, not a private sale). Anyway, I'm noticing that the temp does not always run to running temp (straight up) when I driving. Sometimes it's up, but often I look down and it's hovering about a quarter of the way up (on the cool side). Now I do recognize that this is much better than the hot side, but being a diesel I'd like it to stay at temp. I took it for a spin today and noticed something - the temp holds solid at high noon when it's under load (climbing a pretty decent hill at speed) and when I coast down a similar hill or drive under a light load/flat the temp creeps back down to 1/4 temp. Now when I first noticed this and did my research the obvious answer is a stuck open tstat. After this drive I'm even more convinced that its the tstat. However, last week I dropped the Jeep off at the local dealership and asked them to replace the tstat. They spent the morning on it and called me to tell me that the tstat was fine (they didn't replace it) and they thought there was an electrical issue. Hmmmm.... Seems odd to me. Anyway I picked up the Jeep and did the test drive as above and clearly I'm back to the tstat. The guy also muttered that "they don't see many of these diesels" and that they would need some time to look it over - doesn't inspire confidence. So I'm writing this post to query the experts - Tstat? Electrical issue? What's your vote? Anybody seen something like this that wasn't the tstat? Thanks in advance. Chad 2005 Jeep Liberty Limited CRD - 115k |
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| Author: | QCCRD [ Sun Sep 16, 2012 9:01 pm ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
My understanding is that the failure mode on these is to open up and it's very common. Mine right now is acting similar. I will likely be installing an inline Tstat since it will accept a common part rather than the expensive oem unit. Still some research to do on my options. |
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| Author: | CATCRD [ Sun Sep 16, 2012 10:54 pm ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
Welcome to the boards. It's very common for these thermostats to fail in as little as 50k mi and start opening too early, leading to the exact symptoms you describe. A new OEM one is $100+ but any competent mechanic at your shop should be able to replace it. There's nothing tricky. Other solutions have been devised, such as an in-hose thermostat from another vehicle placed in our radiator hose right at the outlet of the factory thermostat. The failed unit stays in place and the new one acts to control temperature in its place. There are plusses and minuses, but it's cheap: ~$15 and 10 minutes to put in. viewtopic.php?f=5&t=63587 |
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| Author: | Big Montana [ Sun Sep 16, 2012 10:57 pm ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
How did they test the thermostat? Did they take the whole thing out? It's a solid housing that bolts to the side of the engine. I replaced mine a few years ago for doing almost the same thing, and it fixed the problem. I picked it up for a lot less than a dealer would charge at moparpartsamerica.com I'm not sure how this could be an electrical problem. My concern for you is that the temp goes up and down during driving conditions. When mine failed open it never moved from a quarter of the way up. Could you have a head gasket problem? |
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| Author: | dirtmover [ Mon Sep 17, 2012 6:11 am ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
This sounds like your thermostat. The degree of yoyoing you see depends on ambient temperature and how far open the stat is stuck. Expect to lose about 10% fuel economy while it is in this state. |
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| Author: | clehmann [ Mon Sep 17, 2012 8:20 am ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
Thanks for the feedback guys. Sounds like the tstat is the consensus. I'll definitely look into the inline option. From what I'm hearing these things are way more fragile than they should be. And I would agree on the electrical - not sure what it would be! Pretty simple cooling system. The only way I can think that they "tested" the tstat was to take it for a drive and see how the temp did. Which after my testing, as long as they kept on the pedal and didn't really go that far, the temp could well have stayed where they expected. They didn't pull anything apart, so I'm not sure how else they could have tested it. My last car was a 98 Subaru Outback with 215k and I had the head gaskets fail on it around 180k. On that engine, it was similarly predictable, but the symptom was always overheating. I cringe to think of going through head gaskets again, but we'll see in the end. I'm getting 27-28mpg on the highway and 22-24mpg in town, so I'm generally happy, but I would agree that running at temp should help things even a bit more. ...those stats are from the trip computer, and I don't really have enough data to know if I trust it at all, but it's a reference if nothing else. I plan to email my local non-dealer mechanic this week and see what his thoughts are as well. |
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| Author: | dirtmover [ Mon Sep 17, 2012 9:56 am ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
clehmann wrote: The only way I can think that they "tested" the tstat was to take it for a drive and see how the temp did. Which after my testing, as long as they kept on the pedal and didn't really go that far, the temp could well have stayed where they expected. They didn't pull anything apart, so I'm not sure how else they could have tested it. This is probably exactly what they did. The problem is that according to the book anything that's not in the red is "normal". Your dealer probably drove it until it reached the thermostat temperature and gave it the OK. clehmann wrote: I'm getting 27-28mpg on the highway and 22-24mpg in town, so I'm generally happy, but I would agree that running at temp should help things even a bit more. ...those stats are from the trip computer, and I don't really have enough data to know if I trust it at all, but it's a reference if nothing else. Your trip computer is high. Do a search and you'll find more details but I seem to recall as much as 5-6mpg! |
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| Author: | papaindigo [ Mon Sep 17, 2012 10:44 am ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
PRIORITY question at 115k do you have proof positive that the required (at 100k miles) timing belt change was done? If not your absolute #1 thing on the to do list is the TB job, very expensive to let that slide. Comments on temp - obvious general one is welcome aboard and read Sir Sam's NOOB guide: 1. the typical failure mode for the OEM tstat is open or opening early which diverts too much coolant directly to the radiator where it cools, as it should, but prevents the coolant from reaching operating temp (176 F+). If your tstat has failed fully open the temp gauge will never reach the correct operating position of slightly left of dead vertical. If your tstat has failed opening early (as mine did) you can reach full operating temp (see gauge position) on hot days or under load (towing, grade, or AC running) and drop back when the load is removed. NOTE the KJ CRD tstat operates "backwards" IIRC such that what we call open on a normal tstat would be closed and on a normal tstat would result in engine overheating. If I was to bet your dealer had no clue how the CRD tstat operates and when the engine did not overheat they decided the tstat had not failed, like a normal one, closed and they were clearly without a doubt too lazy/stupid to bother to hook up the appropriate scanner to pull the actual temp and compare it to what it should be. 2. the only electrical problems that could relate would be a) a bad temp sending unit in the tstat head (easy test is an IR thermostat reading directly off the top of the tstat housing, b) a bad temp gauge (easy test run the FSM gauge check test); or 3) a bad signal to the temp gauge thru IIRC the Body Control Module or possibly the ECU (easy check same as in "a"). 3. FYI there are some 05s that came from the factory with the temp gauge calibrated for a gas engine (see GDE discussion at http://www.greendieselengineering.com/f ... st/19.page) but that causes the temp gauge to read high not low. 4. While I have participated in the inline tstat discussion and originally suggested the bypass hole addition to prevent temp spikes I elected not to run that mode and am running a replacement OEM tstat in an abundance of caution. 5. Your reported mpg is consistent or a bit high with a stock CRD that does not have a GDE tune which generally will up the mpg 10-20% plus do other good things for your engine. That said your speedometer, odometer, and EVIC mpg readings are poorly, at best, related. Any 1, 2 or all 3 may be off and off in different directions or som or all may be reasonably accurate; reality varies between vehicles. Best check is a run of 25-50 miles on a reasonably level and straight road using a GPS unit to check actual mileage and speed. Once you know actual GPS miles vs odometer miles you can figure an mpg correction factor for hand calculations and compare that with what your EVIC says. |
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| Author: | flash7210 [ Wed Sep 19, 2012 10:23 am ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
I did the Meziere inline thermostat mod when I did my T belt in july. Chose a 195 F t-stat and drilled two small holes in it for bypass. I even left the stock fan and clutch off. So far it all works well with no changes in performance. The real test will come in the winter when engine temp would barely come above 1/4 on the gauge. |
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| Author: | TJ2 [ Wed Sep 19, 2012 1:30 pm ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
Chehmann, Your thermostat is bad (as already stated). It may well be that the fan clutch is also. Your location is important. The majority of members here live in flat lands and it's not uncommon to read about fans being removed for all driving situations. NOBODY drives the mountains without a functioning fan during the summer months. For all the 'interesting' design details in the VM diesel, the heating/cooling system is pretty straightforward. A functioning thermostat will keep it warm enough; a functioning fan will prevent overheating. |
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| Author: | clehmann [ Tue Oct 02, 2012 5:24 pm ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
Hi all, Just wanted to close this one out. I took it to my local mechanic, explained the problem, agreed that it was the tstat, he replaced it and the temp has been rock solid ever since. Thanks for the quick and thorough feedback. I'm sure it won't be the last time I ask for your input and hopefully I can start helping some others along the way. Next up will have to be timing belt and 100k components - mechanic took a peek and he doesn't think it's been done and I'm just over 118k now. Cheers, Chad |
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| Author: | ATXKJ [ Tue Oct 02, 2012 9:11 pm ] |
| Post subject: | Re: 2005 CRD Temperature not consistent |
well that's good advice - but he wasn't really looking at the timing belt - you can't even see it - without doing 80% of the work to replace it... as Papa said if you don't have proof that it was changed - it needs to be changed soon there have been failures at just over the 100K range + even if it's not mileage - it is age, it's 7 years old they will skip teeth and they will break. |
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