Cool down pops!

[OSDart]

After I ran the engine for awhile, and shut it off, there was several loud pops. Started checking things and found the thermostat was the culprit. The recessed lip in the Indy intake is too deep to hold the t-stat snug against the thermostat housing. Hence when pressures build the t-stat bounces up and down. As usual I was in a hurry, so I used a large thin o-ring. No more popping. My question is: are all Indy intakes like this? Or is mine unique? Or is there a special t-stat/ housing?

 

[miller]

The recessed lip in the Indy intake is too deep to hold the t-stat snug against the thermostat housing.

Gonna assume (lol) the thermostat flange has the raised ridge on it for seating. At least you found the prob. If that recessed lip is cut too deep, and the o-ring doesn't cut it, you might try a ring of gasket material to fill the hole. Might last longer.

 

[OSDart]

I think ths is the first time I've run across this problem in 50 years of mechanic'n. The t-stat is a Stant brand (180°). It has the rolled ridge. The only modifications is an ⅛" drilled bleed hole.

 

[OSDart]

Sorry, had Indy intakes on my mind. Ment to say CVR aluminum water pump housing. The housing has a recessed area for locating the t-stat. The t-stat housing has a recessed area as well. Are all water pump housings this way? Or just the CVR brand?