Bad thermostat housing or bad gasket?

[TexasTJ2004]

This the felpro gasket that I have used for thermostat housing:
Fel-Pro 35630 Thermostat Gasket https://www.amazon.com/dp/B000C2ACLI/?tag=wranglerorg-20

 

[512Jeep]

You are sure that if is coming from the space between housing and head? You are sure that it is not from from the connection to the coolant hoses or through coolant thermal sensor? Also, check that the screws are tightened, there are 2 of them

I can see green coolant (I’m doing a flush soon and putting in G-05) on the driver side where the housing and head meet, I’m guessing it’s burning up quickly but you can see the green color on the seam, I will double check the hoses! I’ll see if they are torqued to spec also.

 

[Zorba]

I'm stupid and don't learn quickly. Tight enough is good so tighter is better, right?

That's OK. I'm probably older than you. I was raised to tighten it until it breaks, then back off an eighth. I've mostly learned that's not the best way to do it...

 

[rasband]

I'm stupid and don't learn quickly. Tight enough is good so tighter is better, right?

More important for this kind of thing (similar to the flywheel or clutchpack) is to tighten slowly alternating opposites around the bolts - just like the star pattern when you tighten your wheels.

 

[TexasTJ2004]

Do you have a picture?
I sometimes unscrew a little the top screw and and use it in order to burp the air. If could be that this screw needs tightening

 

[rasband]

Do you have a picture?
I sometimes unscrew a little the top screw and and use it in order to burp the air. If could be that this screw needs tightening

If air burping is necessary we should also ask, did you drill out the air hole in the thermostat? 1/16-1/8" at the top of the housing. This mirrors the stock thermostat.

 

[TexasTJ2004]

If air burping is necessary we should also ask, did you drill out the air hole in the thermostat? 1/16-1/8" at the top of the housing. This mirrors the stock thermostat.

View attachment 347644

I do have a hole in the old thermostat, as it was Mopar. The new one that i have just recieved also already have it drilled. One of the benefits of Mopar.

 

[hear]

Wild. I've never even heard of this. Small sample size at just two 4.0 thermostats but I've never had trouble getting them to seal and never had to flatten the surface.

My LJ did have a leak, but that's because the ignoramus that installed it got the thermostat flange pinched in the housing so the housing wasn't sitting flat.

Was the ignoramus in question the guy who typed that? Because the ignoramus who did mine that way is asking you the question right now.

 

[freedom_in_4low]

Was the ignoramus in question the guy who typed that? Because the ignoramus who did mine that way is asking you the question right now.

haha. no it wasn't. It was the previous owner or whoever he paid to do his work.

I don't think doing it once and then fixing it qualifies one as an ignoramus. It's doing it, then slathering it with half a tube of RTV trying to get it sealed up, driving it as it continues to leak, and then passing it on to a buyer, all instead of just opening it up and fixing it.