Thermostat housing leak

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eradicator006

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In September I changed out the radiator on my 2005 Liberty w/ 3.7. When I did the radiator, I removed the thermostat to help in draining the block. I changed out the rad and put on the old thermostat with the old o-ring. No leaks at all.

I haven't driven my jeep much since then. 3 days ago I started driving it because we got dumped on with snow. It's also been quite cold; -36'C (no wind) when I started her up today. This morning I noticed the heat from the heater (gauge didn't fluctuate) was fluctuating. I checked the coolant and it was low and it was leaking from the thermostat housing. So, appear to have a thermostat leak.

Think a new o-ring and thermostat will fix this? In september, I thought I could get away with reusing the original o-ring because it looked fine. Maybe I was wrong on thinking it could be reused.

FYI: In September I did break off the lower thermostat housing bolt. I had to put in a longer bolt and put a nut on it. I can't see this causing an issue but I thought I better mention it.
 

eradicator006

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Ok I phoned the dealer and they said there isn't a thermostat gasket listed and that it probably comes with the thermostat itself. Does that sound correct? I thought the gasket was separate.
 

HoosierJeeper

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I'd just replace the T stat. Or just try retorquing the bolts, the cold might have shrunk things a bit and all you need is to tighten them.
 

JasonJ

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Permatex makes a sealant for thermostat and water pump housings, can be used with a gasket or alone.

I use this stuff on every job. Where there is a paper gasket, it helps hold it in place, and seals around bolt holes; where there is no gasket, it creates a nice thin sealing layer. Might be something to think about.

Should be able to find it at local parts stores.

https://www.amazon.com/Permatex-22071-Thermostat-Silicone-Gasket/dp/B0007TQW60
 

eradicator006

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Picked up the new thermostat and is has a gasket on it already. Looking at the gasket it looks like it's a crush style gasket. I'm guessing this is all I need. When I took apart the thermostat housing before there was only this big o-ring around the thermostat. There was also no sign of rtv.

Here is something intersting; The new thermostat came in a sealed mopar bag and stamped on the thermostat itself is 'motorad'. I've heard bad things about motorad thermostats.
 

JasonJ

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Picked up the new thermostat and is has a gasket on it already. Looking at the gasket it looks like it's a crush style gasket. I'm guessing this is all I need. When I took apart the thermostat housing before there was only this big o-ring around the thermostat. There was also no sign of rtv.

Here is something intersting; The new thermostat came in a sealed mopar bag and stamped on the thermostat itself is 'motorad'. I've heard bad things about motorad thermostats.

Crush gaskets are nice, seal well and last a long time.

I'm fairly certain MotorRad has been the OEM for MOPAR t-stats for at least a few years now, if not longer. As long as it has the bleed hole/jiggle valve, you're fine. I think MotorRad makes those in Israel too.
 

eradicator006

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Crush gaskets are nice, seal well and last a long time.

I'm fairly certain MotorRad has been the OEM for MOPAR t-stats for at least a few years now, if not longer. As long as it has the bleed hole/jiggle valve, you're fine. I think MotorRad makes those in Israel too.

Ok cool. I should be good then. It has the jiggle valve.

The crush gasket on this thermostat is similar to what is used on the water pump. I learned the hard way with the water pump that it's a one time use gasket. Looks like the same applies to the thermostat.
 

uss2defiant

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just for future reference. your local autoparts store will have the gasket.
I know autozone has a felpro gasket.
 

LibertyTC

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I would tho recommend just buying a new complete Mopar Thermostat. Part #6817 4083 AA
Here is an install diagram. Rubber mounted outside ring is the gasket.
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eradicator006

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I would tho recommend just buying a new complete Mopar Thermostat. Part #6817 4083 AA
Here is an install diagram. Rubber mounted outside ring is the gasket.

That's the part # of the one I bought from the dealer. $35 from the dealer. $40 for a lesser quality one from canadian tire. Never thought I'd see the day when something is cheaper at the dealer.

I just took a look in the service manual I have for the 2005 and it says 115 inch pounds for the bolt tourque. I see lots of threads on the internet where it says 20 ft lbs. Which is it? 20 seems too high to me because the bolts are very small and easy to break. I broke the bottom one off trying to take it off with a nut driver.
 

JasonJ

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That's the part # of the one I bought from the dealer. $35 from the dealer. $40 for a lesser quality one from canadian tire. Never thought I'd see the day when something is cheaper at the dealer.

I just took a look in the service manual I have for the 2005 and it says 115 inch pounds for the bolt tourque. I see lots of threads on the internet where it says 20 ft lbs. Which is it? 20 seems too high to me because the bolts are very small and easy to break. I broke the bottom one off trying to take it off with a nut driver.

The in. lbs measurement seems more appropriate for those size bolts, that works out to 9.5ft lbs. The 2003 SM I have states 115 inch pounds for those bolts as well. About double that for the 2.4l though!
 

tjkj2002

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That's the part # of the one I bought from the dealer. $35 from the dealer. $40 for a lesser quality one from canadian tire. Never thought I'd see the day when something is cheaper at the dealer.

I see it all the time and it can vary from place to place.

Bought a brand new PS pump for my KJ,came with the reservoir mounted and the pulley mounted for $140,all the parts houses wanted $160 for a remaned pump without reservoir and pulley.

Also had the same thing for spark plugs,ignition coils,cooling fan relay,blower resistor,all engine sensors,exhaust manifolds,belt,and much more.
 

eradicator006

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Does anybody know the size of bolt used for the thermostat housing? I want to get a new bolt for the top one. I don't want to break it when putting it back on. The bottom one already broke like nothing. The head twisted right off when I first removed the thermostat.

I'm thinking it's around m6xsomething.

EDIT: Never mind, found it. M8X1.25X24.00 I'll put it here for reference in case someone else needs it.
 
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eradicator006

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No more leaks. New thermostat is in. It was actually the hose that was leaking and not the thermostat housing. I put 2 new stainless steel worm style clamps on the thermostat housing side of the lower hose. That should work until I can get an OEM style clamp.
 

Kal-El

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Grrrrr....woke up this morning and found my T-stat housing is leaking. Gonna try to re-torque first.
 

LibertyTC

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That may work but why not just replace it all at once, including thermostat & a new lower rad hose?
As you can see I have a " Spring" project ahead..
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(Cheers)
 

Kal-El

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That may work but why not just replace it all at once, including thermostat & a new lower rad hose?
As you can see I have a " Spring" project ahead..
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(Cheers)

That's my plan, including the new housing. Just wanted to see if I could keep it from making a mess before I started the project. Got a gift certificate from Amazon so I'll probably get the parts from there.

BTW...does the shroud and fan have to come out for this job?
 

LibertyTC

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I just have the electric fan not the HD cooling package.
As luck may have it, based on placement of the factory clamps, they are still accessible without having to remove the shroud.
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I like the Mopar hose clamps over ring gear types & will have to order them soon.
Apparently there are 2 different sized factory clamps for the lower rad hose.
Remote access hose clamp pliers, are handy for this job.
 

Kal-El

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Mine just has the electric fan and shroud. Looks like the job would be lots easier with it out.
 
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