Brilliant and simple thermostat gasket

[JeepWJ19]

I know the title is weird but after the morning I had it is rather funny.

Dad's WJ 4.0 had MIL light come on. His AC Delco thermostat was junk after only two years and the Jeep wasn't getting up to full operating temperature. Good father and son time.

We have Amazon prime so decided to order genuine MOPAR parts (thermostat and gasket).

Everything is smooth and easy as it should at disassembly. Putting it back was a little more difficult but we got it. Turn the Jeep on and coolant was leaking really badly. Hmmm maybe the gasket wasn't seated properly. Take everything back off, triple check mating surfaces we good to go, put everything back together ANNNNNNND leaking again!

Dad and I just assumed it was the gasket and pressed for time we just went to the local Federated Auto Parts store. Got a measly thermostat gasket for a whopping $1.07.

We get home and sure enough the MOPAR gasket ripped at the under side of the bottom bolt. We had a tough time trying to fiddle with the gasket and making sure it was properly lined up with the bolts etc etc.

We go to open this cheap thermostat gasket and behold! It ACTUALLY had a sticky adhesive like a sticker that mated to the housing! Absolutely brilliant and I wanted to give the guy/gal who thought of that a HUGE HIGH FIVE.

Assembly was then a breeze and we turn the Jeep on and no coolant leak.

Could not be happier. Best $1.07 I've spent.

Also check out this thermostat: (sorry if this picture is rotated, doing this from my phone)



I've never seen that bronze looking tab before. I can't describe it but playing with it, it goes in and out. Don't know if it's like a check valve or pressure relief thing. Any thoughts? Never seen a thermostat with that before.

 

[bdcardinal]

It is a jiggle valve. It helps bleed the system.

 

[Kira]

It assures there's no pressure difference between both sides of the thermostat.

The stat reacts to temperature only therewith.

 

[Chris142]

I hate that sticky stuff. It causes leaks too.

 

[OTCW]

Just an FYI, the jiggle valve should be at the 12 o'clock position in horizontal installations.

 

[JeepWJ19]

Originally Posted By: bdcardinal
It is a jiggle valve. It helps bleed the system.

thanks, did not know that


Originally Posted By: Chris142
I hate that sticky stuff. It causes leaks too.

Time will tell, I guess


Originally Posted By: OTCW
Just an FYI, the jiggle valve should be at the 12 o'clock position in horizontal installations.

I already assumed the jiggle valve should have been at the 12 o'clock position, but thank you!

 

[HangFire]

It probably won't surprise you to know there is a product called Gasket Tack that is designed to keep gaskets in place during assembly.
https://www.amazon.com/Loctite-39158-Hi-Tack-Gasket-Dressing/dp/B000ESIM9O
https://www.amazon.com/Dynatex-49358-Adhesive-Pungent-Solvent/dp/B009XE7VDS

 

[bdcardinal]

If you buy a t-stat that does not have the valve and you are having trouble bleeding it, you can pry it open and stick a Tylenol or asprin tablet in there. It will hold the t-stat open and dissolve on its own. And no I have not tested as to what type of pill works best at aiding cooling, just trying to fend off the assumed next BITOG question.

 

[HangFire]

Originally Posted By: bdcardinal
If you buy a t-stat that does not have the valve and you are having trouble bleeding it, you can pry it open and stick a Tylenol or asprin tablet in there. It will hold the t-stat open and dissolve on its own. And no I have not tested as to what type of pill works best at aiding cooling, just trying to fend off the assumed next BITOG question.


Or just drill a hole in it with the smallest drill bit you have.

 

[bdcardinal]

Originally Posted By: HangFire
Originally Posted By: bdcardinal
If you buy a t-stat that does not have the valve and you are having trouble bleeding it, you can pry it open and stick a Tylenol or asprin tablet in there. It will hold the t-stat open and dissolve on its own. And no I have not tested as to what type of pill works best at aiding cooling, just trying to fend off the assumed next BITOG question.


Or just drill a hole in it with the smallest drill bit you have.


That works too. At least for me I always had a bottle of Tylenol or Excedrin in my toolbox and that was faster than setting up a drill.

 

[Garak]

How about an O-ring like the Europeans use? North America's fascination with paper gaskets in thermostats is like what, 25 years out of date?

 

[bullwinkle]

Originally Posted By: Garak
How about an O-ring like the Europeans use? North America's fascination with paper gaskets in thermostats is like what, 25 years out of date?
If it only had a groove... (newer US engines use O-rings, unlike the 4.0's ancient '60s technoology).

 

[redbone3]

What is it with Mopar thermostats. I had two Neons and the thermostats literally broke on both of them. In 55 years of driving those were the only thermostat failures I have experienced.

 

[JeepWJ19]

Originally Posted By: HangFire
It probably won't surprise you to know there is a product called Gasket Tack that is designed to keep gaskets in place during assembly.
https://www.amazon.com/Loctite-39158-Hi-Tack-Gasket-Dressing/dp/B000ESIM9O
https://www.amazon.com/Dynatex-49358-Adhesive-Pungent-Solvent/dp/B009XE7VDS


It actually did surprise me. Thanks for that though. Tis why I love BITOG.

 

[JeepWJ19]

Originally Posted By: redbone3
What is it with Mopar thermostats. I had two Neons and the thermostats literally broke on both of them. In 55 years of driving those were the only thermostat failures I have experienced.


Sorry you had trouble with MOPAR thermostats.

The one that I got was branded MotorRad or MotoRad. Can't remember the name.

But the thermostat I replaced was an ACDelco

 

[Yah-Tah-Hey]

My 04 Camry V6 thermostat uses an O ring type gaskets that fits over the OD of the thermostat housing.Position thermostat with jiggle valve aligned with upper stud, install housing and properly torque nuts to 71 in. lbs in criss-cross pattern. Gasket is deformed to engineered specs and no leaks. In all my years working in power generation, I never saw an o-ring leak when properly installed, NEVER. Not even under 3000 psig.

 

[Garak]

Originally Posted By: bullwinkle
If it only had a groove... (newer US engines use O-rings, unlike the 4.0's ancient '60s technoology).

I know.

North America was just way, way too late to change.

 

[SHOZ]

I see gaskets that have one hole with lobes like an internal lock washer to hold the gasket and bolt as they should be.

Most t-stats that I've messed with have the outer rubber ring around them. Except my Accent that uses a paper/steel gasket.

 

[jeepman3071]

I believe the OEM Mopar gasket is a FelPro. I haven't had any luck with them either, they suck and are too thin.

I did get one from Autozone which was a bit thicker and has been flawless on 3 different 4.0 engines. Pretty much the only thing I have bought at AZ that wasn't of terrible quality.

The OEM thermostat is a Motorad. They work pretty good, but I found on the scan gauge that two different Motorad stats had pretty wide temperature swings. From 195-212* and back with all the air bled out. I swapped to a Stant Super Stat 195* on both my Jeep and the other one I maintain and the scan gauge shows a very slow swing between 195*-205*. The Stant is much thicker in the middle, so that might have something to do with it. I also have a high flow thermostat housing, and a 3 core radiator.