Temperature fluctuation, thumping / thugging noise engine off

[mechhound]

Originally Posted by WMX267

Regarding the TSTAT, I wonder whether it could be defective because I don't overheat. My gauge would go never reach more than 55% of the gauge range, assuming 50% is normal driving temp. How can a faulty TSTAT explain the thumping sound?

Is there a quick way to determine intake and return hoses of the heater core?

As far as determining intake and return hoses of the heater core, I believe the water pump DRAWS the coolant through the heater core. So the hose associated with the water pump would be the return hose. Honestly I never gave the whole situation much thought, so I could be wrong here. If you are asking to determine which heater hose to disconnect to burp the system, I would try the one NOT associated with the water pump.

As far as the guage only going to 55%, The temp guage is not that great. As far as the thumping sound, a lot of strange things can happen when the coolant is not circulating properly.

The things I suggested in my previous post is just what "I" would try in desperation at this point. I would even consider trying it without a thermostat . Good luck and please keep us posted. I'm curious.

[inafogg]

if i understand you correctly the gauge would be right but its reading water
temp at the sensor!!if we have an air pocket its O/H.(thumping noise)
since i dont see anything about special bleeding of the system & i owned a 92 there is none.which i now would do a compression test to see if we are blown between coolant passage.