Hello all,

I was wondering if someone could give me the low down on the thermostat issue that seems to be popping up more lately? I did a search in the forum and found topics that touched on the idea (enough to where I think I know what's going on), but wanted to address it directly. Here's what I've got:

1. No abnormal engine issues, codes, etc.
2. Thermostat is consistently at 1/4 of the temp gauge, even after 20-30 minutes+ of driving. Lows at night and when I leave in the morning are averaging between 20-35 degrees.
3. If you guys seem to think it's bad, what needs to be done or how involved/costly is the fix?

Thanks!

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Josh

2012 Jeep Liberty Latitude Edition 4x4 - Brilliant Black, RRO Rockfather II OME lift, 245/70/17 Duratracs

*sold*
2005 CRD Limited 4x4 -Inferno Red- Selec-Trac
SEGR, Grabber AT2's, 2.5" Daystar

read this and see if it helps you

viewtopic.php?f=5&t=50940

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2005 CRD Limited
SEGR
WEEKS Kit (removed EGR, FCV),
Gen 2 Fuel Head
GDE Eco Tune
ARP studs
Etechno (7v) Glow Plugs
F37
Kap 193 thermostat
Carter Lift Pump (Modified wiring harness)
Fumoto (CRD-108)
Bypass oil filter (2 micron)
Samco
Provent
Sears P-1 Battery
Secondary 2 micron fuel filter

To spare me from reading every post in the 28 page topic, it sounds like I need a new one. My next question is, has Chrysler released a TSB on this and have they re-engineered the thermostats to correct whatever problem they were having, or is the custom-made thermostat the only way to go right now?

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Josh

2012 Jeep Liberty Latitude Edition 4x4 - Brilliant Black, RRO Rockfather II OME lift, 245/70/17 Duratracs

*sold*
2005 CRD Limited 4x4 -Inferno Red- Selec-Trac
SEGR, Grabber AT2's, 2.5" Daystar

You do need one...we have all studied it in detail.

DC has not issued a TSB on it.

DC has not made a modified unit.

Either keep buying new ones or join the rest of us to get a modified unit. The trick with the modified unit is that you can then replace the actual thermostat yourself in the future without having to buy a new thermostat housing/unit...

VM did not do us any favors but hey, they are Italian and why go simple when complex will work...

_________________
2005 CRD Limited
SEGR
WEEKS Kit (removed EGR, FCV),
Gen 2 Fuel Head
GDE Eco Tune
ARP studs
Etechno (7v) Glow Plugs
F37
Kap 193 thermostat
Carter Lift Pump (Modified wiring harness)
Fumoto (CRD-108)
Bypass oil filter (2 micron)
Samco
Provent
Sears P-1 Battery
Secondary 2 micron fuel filter

Happy to chime in on this one. I'm the author of the above listed thread and designer of the modified unit.

I have specifically tracked down why the units fail around 50k miles to the spring inside the unit that supports the thermostat getting weak over time. When the spring that pushes against the piston in the opposite direction begins to get weak, the thermostats start opening earlier and earlier. This causes the engines to run cold and the thermostat needs to be replaced. Additionally to this, the factory thermostat has a 176º F opening temperature which has been said to be too cold for optimal fuel economy and engine life. I would recommend changing your thermostat as soon as possible to get your operating temperature up. This will also help fuel economy. What codes do you have from the check engine light you mentioned? there may be other issues. I never threw a check engine light for my OEM thermostat, but it may not have been as bad as yours (your spring may be weaker than mine was).

I would also recommend checking your codes and posting them on the forum to make sure there is not another issue.

Keith (<--Great guy and very trusted and knowledgeable that knows a wealth of knowledge about this engine) that owns GDE (a major tuning company for the CRD's) recommended a engine operating temperature of 195- 200º F if it was possible. The modified units I make allow for a 192º thermostat which is as close as available to the 195-200º F for a thermostat that could be fit into the factory unit when modified.

I would ultimately recommend the modified unit, but there is a waiting list (posted on the first page, first post of the thread). PM myself if you want to get on the waiting list. I'm not trying to market my design here, I am already backlogged with a lot of orders, I just know it is a good option. The factory thermostat is also a great option and should still return great economy numbers and get you back to stock temperature which is better for your jeep than running as cold as you are right now and it will probably last another 50k miles. If you are planning on keeping the jeep for no more than 50k more miles the a factory unit is probably the best option for you.

If you are fairly handy with a set of tools, you can change your factory thermostat unit yourself to save on the mechanic cost and just buy the OEM unit itself. It has 4 smaller coolant hoses going to it and one large upper radiator hose and a sending unit that all have to be disconnected/removed and 3 bolts to the lower thermostat to block gasket, the gasket needs to be scraped and replaced and one upper bolt on the thermostat housing. Its price is about $100 plus shipping from a website like moparonlineparts.com (wholesale) and closer to $150 from a Jeep dealership at regular retail price.

My unit is $145 and has a 192º F replaceable thermostat inside (included in the price). The replacement thermostat is available at any Autozone or similar chain parts store and is only $9.99 plus tax. to replace the thermostat in my modified unit it is only 2 bolts to remove a water outlet, remove reusable rubber gaskets, replace $10 thermostat, bolt back together. Also since the modified unit is not completely removed you do not lose as much coolant so changing is less of a hassle. If you plan on keeping your CRD for over 50k more miles it is, in my opinion, worth it to upgrade to the modified unit.

Good luck and I hope you get your CRD running up to operating temp soon - they like to be warm

- Mark

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Previous-05 CRD KJ;Current-2010 Taurus SHO Twin Turbo (450HP), 2014 Subaru Forester Turbo (stock)

i'm at 90k on the original...

_________________
"Never mind the maneuvers, go straight at "em," Lord Horatio Nelson

2005 Jeep Liberty CRD

148k before my thermostat went. Going to replace it with a factory one since it did last so long. Only reason im going for a factory replacement is because im impatient and dont want 14mpg while waiting for the upgraded version

_________________
06 CRD limited
Frankenlift, JBA 1/4 top plate, 3 clevis rings, 3 stacked iso's
JBA UCA and quick disconnects
Procomp rockkrawlr 16x8 4.25bs with 265-70-65 General Grabber AT2's
Mopar full skid plates, JCR stage 3 Rock Rails
Kenwood HU, 6.5 pioneer marine grade door speakers, JL stealthbox kenwood amp
GDE HOT tune
Soon to come
RL Rock monitor bumper

_____

And please allow me to give Kapalczynski a ton of credit (all the credit actually) for all his hard work and dedication. I answered your question quickly but Kapalczynski is doing the yomens work for the CRD community to make this CRD challenge manageable.

_________________
2005 CRD Limited
SEGR
WEEKS Kit (removed EGR, FCV),
Gen 2 Fuel Head
GDE Eco Tune
ARP studs
Etechno (7v) Glow Plugs
F37
Kap 193 thermostat
Carter Lift Pump (Modified wiring harness)
Fumoto (CRD-108)
Bypass oil filter (2 micron)
Samco
Provent
Sears P-1 Battery
Secondary 2 micron fuel filter

I saw that a guy over on the GDE forum tried one of these:
http://cdn.apdapd1.com/images/product/medium/FIMG/MEZ/MEZ-WN0071.jpg

from here: http://www.autopartsdealer.com/meziere_inline_thermostat_assemblies-p355150-g.html

Seems like it might be worth a try for $57 while Mark gets caught up, no?

We have to replace the radiator hose anyways, right?

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2006 CRD GDE ECO/HOT Tunes and TCM swap and HD Mopar Torque Converter, EHM
2003 Jetta TDI 155K all stock
1957 International V8 Diesel

2nd on Kapalczynski, the guy has is sprockets in gear. Things he's done on a CRD and the new one, the Commander for his relative, are just amazingly thought out. I'd really like to spend a weekend working with him on some of this stuff.

Mark has been opening a lot of old and a few new thermostats recently and he finds that (mostly) the springs go weak in the bad units, allowing the 'stat to open easier.

If the bad unit top valve opens too soon the lower valve closes early also. If you restrict the flow at the top with one of these devices you may cause a bottle neck. There is still some bypassed to the heater core if you are running heat in the cabin. I am sure you are at this time of year.

That said , I think that this would work. I don't know if any damage could be caused by pump restriction (over-pressure). Probably keeping the truck at operating temperature is the best thing to do anyway.

Thanks Squeeto... good food for thought.

If you know for a fact that the stat is sticking open, then the bypass should be partially closed. The danger may be in situations where the inline stat closed causing the pump to dead head and possibly cavitate.

On second thought, I will patiently wait for Marks excellent work to arrive...

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2006 CRD GDE ECO/HOT Tunes and TCM swap and HD Mopar Torque Converter, EHM
2003 Jetta TDI 155K all stock
1957 International V8 Diesel

I did my thermostat yesterday, took about 2 hours. It was harder than I thought but I havent wrenched in a few years.

Things I found that really helped; take the airbox out completely, it pops right out after disconnecting top, sensors, etc..., loosen the air tube where it goes into the turbo and rotate it to get to the rear bolts on the thermostat. Scrapping the gasket off is a little difficult due to the angle so be patient.

After refilling with Zerex coolant, I gave it a test run. Before I changed it, the jeep would take 15 minutes to warm up and needle was never over 1/3 mark; cabin heat was okay at best.

Now it warms up in less than 5 minutes, cabin heat is very good and I'm sure my VM is off at that point. I bet my milage goes to where it should be now.

Good luck, but do it! I had to wait almost a month after getting the thermostat.

Paul

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05 CRD Sport 2 1/2" RR lift, EHM, ORM, Predator II module
99 Ford F350 6" Superlift, V10!, 38.5x15" TSLs, 4.56s.....

I am trying to think through this problem. If I install an inline thermostat in the upper radiator hose as close to the engine as possible, the only flow I will block is through the radiator. The cabin heater is still circulating and the viscous heater is still functioning. So even with the radiator completely blocked, the coolant is still circulating around the engine and heaters. If this is true, an inline thermostat should work fine if after opening it does not block or resist flow to the radiator. If my understanding of this is incorrect, we need additional information that we cannot get from the shop manual.

If we use a standard thermostat used in other larger diesel engines, then flow resistance should not be an issue. Just make sure the heating element of the thermostat is installed toward the engine.

I've been thinking the same way as you. I have mine ordered but the only tstat that I could get through them was a 180. This will be better than what I have now (a nonworking tstat) but I hope it will be enough. I've heard of people drilling a hole in the tstat to allow more coolant to pass through to keep pressure down. This seems like a good idea in our applications however it will take longer for the tstat to warm up and open since a very small amount of coolant will be allowed to circulate while cold. One dumb question, the water flow comes up out of the existing tstat and down through the radiator, right?

TennesseeCRD, You are correct, the water pump sucks coolant from the lower radiator hose, engine and heater returns and pushes the coolant through the thermostat to the upper radiator hose and then down through the radiator. If you put the thermostat in backwards (with the spring/Sensor facing away from the engine) then the inline thermostat will not work correctly. If the thermostat is installed as close to the engine as possible and with the sensor facing the engine, it should open when the coolant circulating through the engine reaches the thermostats temperature setting.

We should think ourselves lucky that we even have a thermostat. Seeing some of the other design choices they made on this vehicle I'm surprised they didn't go for some hair brained over complex system like putting a clutch on the coolant pump. What better way to guarantee catastrophic engine damage when the part fails.

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Share your ideas freely at https://www.facebook.com/groups/libertydiesels/

Well I did the inline tstat housing. I did buy a 195 degree tstat to go in it from NAPA. 2 days and about 75 miles or so and no ill effects yet. I see now why VM did the viscous heater. Even at idle with the new tstat (and my viscous disabled) it won't heat up past a couple of knotches. However 4 or 5 minutes into driving (even at slow rpm's , my 1 lane county road is 1 mile and 5 minutes long) and the guage is straight up 12 o'clock (or maybe a 1/4 hair under). I could drive all day before and it wouldn't even reach the quarter mark. I did drill a very small hole in the tstat disc. I erred on the side of caution with this thinking that it may help relieve any excess pressure and also allow heated coolant to pass by the tstat easier in a case of an air lock at the top of the cycle that would otherwise prevent warm coolant from circulating to the new tstat. After the install I'm not sure this was necessary. We were in alot of stop and go traffic last night and the temp stayed right up there where it should. Pros to the install is that it seems to be working like a tsat should, and it took all of 15 minutes to do. Cons so far is that the inline unit is very noticable when you open the hood, you have to cut your rad hose and get it right (I didn't want to cut mine too short with the first cut so I actually had to cut it twice more before I got it to the right legnth). I'll keep you guys posted if anything bad comes of this, but so far so good.

Thanks for the information TennesseeCRD we will be looking forward to your future updates on the in-line thermostat installation. Just to be complete do you remember what size drill bit you used to vent the thermostat? Also, what diameter housing did you use? Did you use a larger housing with reducers, or just the same size as the upper radiator hose?

The housing that I purchaced has a one and a half inch inlet/outlet. That was the only size offered that I could find, however it turned out to fit our upper hose perfectly. I butted it up as close to the factory tstat outlet as I could. It is actually touching. As for the drill bit, it was the smallest in my collection. I know that doesn't help haha. It isn't stamped and I don't have a micrometer. The only way I can relate it to you is, it is about the size of the head of a screw that you would use in your eyeglasses. .