mine is failing too so when it gets cold for right now i just throw something really thick over my grill and it will heat up reather fast even in the 30's but i was just about to order a oem unless some one recamends somthing better.... and for those of u overheating do u have a addtional trans cooler it will help when going up step grades and pulling stuff, my jeep would randomly over heat and did some tests and could not find any thing rong. so i talked to my jeep master tech friend and he said jeep radiators some time just dont cool right so i took a chance a bought a 300 doller oem one and shure enuf it fix that and put on a transcooler and fan clutch and i have not seen it go over half since i have done that and i took her up the mountins and beat on her really good and the needle did not move at all!!!

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05 crd, old man emu, jeepin by al upper control arms, spider track wheel spacers, bf mud terrain t/a, full 3'' with a magnaflow exhaust,rocky road super sliders,skid row gas tank cover,surco roof rack with hella 500 lights,front hooks,b&m trans cooler!

Yes that is a guy on here machining new thermostats so that the it can be easily replaced without replacing housing and all. Here is the post http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=50940 i am getting ready to ship my old one to him as we speak to have it done. Because in all honesty i dont want to have to pay that +100 to have it replaced again.

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My CRD Build Thread
Soon to Come:more lights

My questions are:

1. Does my failed thermostat keep my CRD engine running cooler?

2. Does the new OEM thermostat increase engine temperature?

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2006 Liberty Limited CRD, Deep Beryl Green, Yeti tune, Arp studs, new cams, rockers, lifters, TB. "Green Monster"
2005 Liberty Sport CRD, Deep Beryl Green, GDE Hot Tune, ARP studs. "Rocket"
1982 Fiat 124 Spider Convertible. "Fiona"

Yeah, a bit bogged down, only have shipped 2 units out so far and have 2 more almost ready to ship. Winter weather is hard since my lathe is in the garage and hates cold starts. The capacitor type motor in the cold draws ALOT of current and has to restart several several times before it spools up. This causes the circuit breaker on the house to go several times. I really need a dedicated shop area...hopefully I can build on soon. The high for the day in Colorado springs a few days ago was 9ºF and the garage has been stayin pretty cold and uncomfortable to work in. Takes alot to heat the 2 car garage also

Mine failed and was at about 150ºF, probably the only reason it was this hot is the VH was running the whole time...also killing fuel economy by the way. A stock unit opening temp is only 176ºF and it still sits low on the needle. Even the 192ºF modified unit I make sits just barely touching the top mark slightly to the left side at a 192ºF opening temp.

I appreciate you donating to the cause, I hope to get this project spun up to a faster turn out rate soon, especially by this summer...maybe even spring late winter/spring If I get a little shop area built to work in.

Here's the pic (thanks GDE) that shows actual gauge temps for reference. The drawn in orange line is where mine sat when it had failed on my CRD.




- Mark

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

1) The failed unit will run your engine temp around 150ish (if failed open - as far as I know no ones has failed closed as of yet), even if completely open since the VH will turn on around that temp like it would only do doing a warm up cycle (GDE - forgive me, I dont remember the exact temp you told me once ). So yes, it is running cooler than designed to run, it also causes the VH to run nearly constantly, and decreases economy.

2) The new OEM thermostat is the same temp as the original temp and opens at 176ºF (unless there is a new designed one from them I don't know about?) so it will run as hot as the original when new and about 25º hotter than a failed one - this allows better efficiency/economy.

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

I read about members who have hastily run to replace their failed thermostats with new ones hoping to gain cabin heat & MPG and being disappointed when little changed.

Past posts about cracked heads and failed head gaskets due to high engine temps, convinces me that keeping the old thermostat in its place will be saving me money and a possible headache.

If in fact my failed open thermostat does keep the engine cooler then it is beneficial and I am happy with it, because keeping this little engine running is my main concern.

So unless a failed open thermostat will do damage to my engine, I will be keeping it as it is.

My Viscous heater and butt warmer work well and are enough heat in the cabin while I wait 10 or so minutes for the engine coolant to warm the heater core.

A remote engine starter may be a better way to spend our dollars if we want to find a heated cabin waiting for us when we go out driving in cold weather.

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2006 Liberty Limited CRD, Deep Beryl Green, Yeti tune, Arp studs, new cams, rockers, lifters, TB. "Green Monster"
2005 Liberty Sport CRD, Deep Beryl Green, GDE Hot Tune, ARP studs. "Rocket"
1982 Fiat 124 Spider Convertible. "Fiona"

Honestly when my thermostat failed it failed open and my fuel mileage acttually dropped like a rock. I went from around 22 to 19 in town on the highway it didn't change much but it did finally get all the way up to operating temp. Yes it won't hurt to leave the failed thermo in it but your gas mileage will never be the same while it is cold outside.

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My CRD Build Thread
Soon to Come:more lights

I have some other thoughts....

My economy also dropped...mainly noticeable on highway mpg more than city.

Running cold means running rich and a drop in economy (I know you dont mind a tiny bit of economy loss if engine longevity is better...if it is better). More soot is produced aslo (more is also dumped back into the engine).
More soot in the CRD intake would be my biggest concearn...its bad for everything, turbo, sensors, EGR, etc. I would also be concearned of the VH longevity, but I don't think anyone's has failed. You shouldn't ever have to worry about overheating w/ a 176º thermostat. Running 176ºF IS already runing cold. Keith at GDE even said we should be running around 200ºF on our engine...granted that is an opinion, but other diesels run those temps also so I think it to be a good one. The only issue with overheating with a 176º F thermostat is other parts of the cooling system like the fan clutch failing. MANY CRDS have bad ones and don't know it untill the go to climb a hill and get hot. The reason for this is the CRD's cooling system is very efficient.

Since I haven't heard of the VH having any longevity issues the only real concearn is the possible soot especially with it going through the turbo and also potentially killing an EGR valve. Sensors can usually be cleaned. I think the EGR can be usually unless so much built up that it caused some sort of mechanical failure in the valve. The turbo...now that is a bit of $$. Not sure if soot on the blades can cause extra bearing wear with a difference of weight if not distributed on them evenly or not, but I wouldn't chance it myself. The CRD was designed to run 176, other diesels run 200ish, going colder just doesn;t seem like a good idea. Even on conventional gas engines w/colder tstats cause additional cylinder wall wear w/fuel condensing on the cylinder walls. This is why modern engines are now running even hotter temps (my 07 charger is a 205)...reduces engine wear and is more eficient also.

Sorry about rambling...just some things to think about.

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