Installed new thermostat today

LibertyCRD · **Posted:** Sat Jun 26, 2010 1:08 pm

Just thought I'd confirm a few details that have already been discussed about the thermostat.

First of all, there are FOUR (4) bolts that physically hold the t-stat onto the engine. Three go through into the block, and the fourth mounts the t-stat to the bracket on the top.

In my opinion, the easiest thing to do is to start disconnecting all the hoses from the t-stat and move them out of the way, then I disconnected the CAC hose from the CAC side and folded it behind the turbo to get it out of the way. I removed the air box and the turbo inlet hose to make more space. I carefully stuffed a shop towel into the turbo to prevent any debris or coolant from getting into it. I did not waste time partially draining the coolant. Whether you drain it or not, you're going to have coolant pouring out when you pop the hoses off, so it's a waste of time to drain the radiator down some first. You won't lose all that much coolant.

Once all the hoses are out of the way and everything is disconnected from the t-stat...you can unscrew the temp. sensor from the back of the t-stat. This takes a 3/4 open end wrench. Then remove the 4 bolts holding the t-stat onto the engine. This takes a 10mm socket and long extensions. The t-stat will then easily pop off with light force.

The old gasket is tough to get off. I found that a razor blade was the easiest thing to use. My razor fits into a pop-out knife kind of thing...so it was safer to grip the body of the knife and use the razor blade to peel the old gasket off. I then spent about 15 minutes scraping the old gasket material off. Get as much of it off as you can. Try not to let any of the old gasket fall into the engine.

Then I put a small amount of black silicone onto the new gasket to hold it onto the back of the new t-stat, and bolted the new t-stat onto the engine. The rest is attaching all your hoses where they belong, reinstalling the turbo hose after you pull the show towel out and make sure NONE of it was left inside the turbo, reinstalling the airbox, and topping off the coolant.

I bought a gallon of Zerex G-05 at NAPA for $12 to top the coolant off with, and of course you top it off at the reservoir on this Jeep, not at the radiator itself. Total job took almost 2 hours. Just make sure you remember where all your hoses hook up before you start pulling them off. There are 5 connections to the t-stat altogether I think.

After I get to drive it some, I'll report back on my findings with the temperature the Jeep runs at now.

fastRob · **Posted:** Sat Jun 26, 2010 1:20 pm

Did you get the hot European 192* or the stock 182* thermostat?
How much did it cost?
Where did you get it?

LibertyCRD · **Posted:** Sat Jun 26, 2010 2:53 pm

I didn't know there was such thing as a Euro t-stat. I ordered the part number listed in the timing belt parts list sticky. $94 from moparpartsamerica.com

LibertyCRD · **Posted:** Sun Jun 27, 2010 2:37 pm

Well I drove it this morning and the engine heated up faster...needle on the gauge went straight to just before the half-way mark and stayed there all day. It's obviously running better now.

Will start monitoring to see if there is any change in MPG from this point..

bugnout · **Posted:** Sun Jun 27, 2010 9:11 pm

Good timing. I'm getting ready to change mine out.

LibertyCRD · **Posted:** Sun Jun 27, 2010 9:22 pm

For those who haven't removed the stock air box: There are two sensors to unplug. Then once you get the top lid of the airbox off, and remove the filter, the bottom section of the air box just pulls upward. There are 3 rubber grommets that hold it in place (similar to the engine cover). It might take some force...but if you pull it'll just pop off. Having the air box out of the way completely made the job much easier.

A mistake I made: I had the t-stat loose and removed from the engine before unscrewing the temp. sensor. I should have unscrewed the sensor before removing the t-stat. I ended up having to place the old t-stat in a vise to hold it solid while I unscrewed the temp sensor.

When I finished the job, I took a garden hose and washed down all the underhood parts that had coolant splashed on them during the replacement. Cleaning up all the coolant by spraying it with a hose is a good idea.

jeepdan · **Posted:** Mon Jun 28, 2010 12:26 am

Thanks for taking the time to post your work, that is good timing for me as well. I received my new thermostat last week. Since my jeep is hitting five years old I'm going to change the coolant when I replace thermostat in a week or two. I had anticipated doing everything this fall with a timing belt service, but I think I will wait until next year for that as I only have 82,000 miles on the CRD at this time. I purchased the orange Mopar coolant.

Big Montana · **Posted:** Mon Jun 28, 2010 5:29 pm

I like this post. Can we add the part number for the gasket and the thermo and move it to the tech section? This could help many people. I need to order mine from moparpartsamerica, but I didn't have the part number for the gasket. Does the gasket come in the box? I thought I read a post that said you had to order it.

LibertyCRD · **Posted:** Mon Jun 28, 2010 6:37 pm

Here is what I ordered:

5142601AA - Thermostat - $93.49
5066806AA - Thermostat gasket - $1.76

My thermostat did not have a gasket in the box. The prices will fluctuate some over time too.

Today, my EVIC is showing 28 MPG. It had been settling in around 26.5 MPG before the t-stat change on my normal driving routine. (My EVIC is not accurate, but it gives me a somewhat decent idea of how I'm doing). I'll have concrete numbers to share later...

TJ2 · **Posted:** Tue Jun 29, 2010 12:03 am

Nice write up. Thanks for the pointers. My t-stat is stuck open and I've noticed an fuel economy improvement from about 21 to 25 mpg since the weather warmed up. So, I'll be replacing mine long before fall temps start to drop.

There's a note in the FSM regarding the 2.4 and 3.7 liter gasser t-stats. It says that sludge build-up is a danger when running with a bad t-stat (or none at all). My concern is that, unknown to me, the stat was bad when I bought the Jeep. I'm wondering how long the PO had driven it like that?

bugnout · **Posted:** Wed Jun 30, 2010 10:06 pm

Just changed mine out. Took the longest to clean the old gasket off the block. Used a shop vac to clean up all the bits of gasket.

Agree completely, draining in advance is a waste of time, Your going to dump a half gallon on the floor, just disconnect the hoses and clean up when your done.

LibertyCRD · **Posted:** Thu Jul 01, 2010 10:55 am

So far, my MPGs seem to be up about .5 or so. I'm at half tank...and I've got 210 miles or so. Not much improvement...but it should be a bigger improvement come Winter.

CRD Joe · **Posted:** Fri Jul 02, 2010 9:57 pm

Please explain the motivation behind this. My truck is at 60,000 miles. When should a tstat be changed out do you guys think?

tjkj2002 · **Posted:** Fri Jul 02, 2010 11:09 pm

CRD Joe wrote:

Please explain the motivation behind this. My truck is at 60,000 miles. When should a tstat be changed out do you guys think?

You should replace the t-stat and all hoses when you change the coolant,so every 2-3 years.

Your pushing it on any coolant going over 3 years,even the "long life" stuff.

bugnout · **Posted:** Fri Jul 02, 2010 11:42 pm

CRD Joe wrote:

Please explain the motivation behind this. My truck is at 60,000 miles. When should a tstat be changed out do you guys think?

I was going to change it when I did the timing belt at 100k, but I have another 10k to go. My stat has been opening at 163 degrees for the last 5 months. Noticeably lower fuel economy when my engine never warms up.

So if yours is working fine, change it the next time you do a coolant flush, timing belt change or some other maintenance where it would be convenient.

dgeist · **Posted:** Tue Jul 06, 2010 9:33 am

tjkj2002 wrote:

CRD Joe wrote:

Please explain the motivation behind this. My truck is at 60,000 miles. When should a tstat be changed out do you guys think?

You should replace the t-stat and all hoses when you change the coolant,so every 2-3 years.

Your pushing it on any coolant going over 3 years,even the "long life" stuff.

Oi... I know yours is a voice of reason and experience, TJ, but I'm not sure I would ever endeavor to change ALL the coolant hoses on a CRD unless the engine happened to be pulled at the time. With the way they are priced, that would run about $16k for parts alone

I know the main lines aren't bad to do and would really be the ones that would cause the biggest issues if burst, but has anyone gone to the effort to actually replace all the accessory coolant feeder lines and what was the damage?

Dan

LibertyCRD · **Posted:** Tue Jul 06, 2010 10:55 am

There are at least a half-dozen different coolant lines under the hood on the CRD. There is no way I would replace all of them just for the heck of it. Factory replacements for all those would probably cost an arm and leg. You might be able to just use standard heater hose and bend some of them enough to make them work OK....which would be cheaper. But with almost 86K on the clock now, I noticed no cracking or deterioration whatsoever on any of my hoses...so "if it ain't broke don't fix it" applies here.

Hydraulic Jack · **Posted:** Tue Jul 06, 2010 1:37 pm

Has anyone found any direct replacement silicone coolant hoses for our CRD's? HJ

Hydraulic Jack · **Posted:** Wed Nov 23, 2011 9:04 pm

Nobody makes silicone radiator hoses for our trucks? HJ

Joe Romas · **Posted:** Thu Nov 24, 2011 3:32 pm

Hydraulic Jack wrote:

Nobody makes silicone radiator hoses for our trucks? HJ

I've owned close to 20 total light diesel vehicles and some had very high miles.
I've found since diesel engines run cooler the rubber hoses just don't fail! When I replace the radiator I replace all the hoses too.
It seems the hoses have gotten better over the years and the plastic ended radiators are now the weak point. It does not seem to matter what brand vehicle it is.

Installed new thermostat today

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