Hello everybody my project is a 76 K5 Blazer run in the 87 l98 or the tuned port injection out of a Camaro it's a 350 has the TPI and I have a coolant leak I replaced my thermostat housing gasket once still had the leak replaced it again with a really good $10 gasket and was driving home today in the coolant is still coming or still peddling around the thermostat housing so I was wondering if it could be an intake bolt and intake gasket or I'm pretty sure it's not the throttle body cooling lines any help out there

 

Use a tap for intake and clean the bolt threads with a die. With crud on the threads it may get tight before it actually clamps down on the gasket.

 

Taps should only be used for cutting new threads. A thread chaser is used to clean/renew threads. The thermostat housing might be warped or like you stated coolant spraying from the to bypass hose. Clean the area and run and observe.
If the thermostat housing is warped four seasons, delco makes a new one or you can put sand paper on a piece of glass and resurface the mating surface. Make sure the upper rad hose and tb hose clamps are tight.

Housing are the same tpi 85-92

 

Look your thermostat housing over good, I had one crack years ago by one of the bolt holes. It may have been from over tightening or it was warped and then cracked when tightened.

 

OK thermostat housing isn't cracked. Or warped

 

I replaced my stat years ago, and had a leak afterwards. Only thing I could do to make it not leak was to put RTV on both sides of the gasket and then install. Since then, it's never given me any problems. Was it a one time fluke, or warped housing? Who knows, but I just do it now every time and haven't had an issue.

 

my $0.02 is that its cracked, but hairline so you cant really make it out. mine cracked barely, had a pool of dried coolant on the intake. wasnt really concerned since i was replacing the motor. when i did, and took off the housing, it broke apart almost immediately.

 

Had good luck using a good gasket and the brown brush on permatex no silicone
Id still try a new housing the GM ones are good and usually straight
Stay way from the stuff with the orings in them.

Similar problem on a 90 one ton the good gasket and eliminating silicone did it. Same with the water pump.
Go just past snug on them no need to really torque them down. Maybe thats whats happening

 

I believe my mechanic did this to me...I sat the thermostat on a flat surface and it seemed to be kaddywompis. Also I could no see the crack...but I believed it was leaking from one of the bolt hole areas...isnt it possible it was a hairline crack that cannot be seen???

 

Yes, totally possible. As it contracts and expands under heat cycles, YOU may never see it, but water can.

....and I saw you said kaddywompis. I woulda spelled it caddywumpis. I said to myself is this guy from NC???...and sure enough you are!!!!

 

 

Haha yupp North Cacalaky. Yeah well I replaced the housing with the gasket on some guys on here recommended. Took out the 195 t stat and r ellaced it with the 180 t stat. The hose was too long and was bowed up against the radiator and touching the compressor!!! So I trimmed that, turned it some and it sits perfect! Car is running great, I also replaced the C oolent reservoir jug as well. I'm happy with everything. I'm taking it to a whole to get a pressure test and thorough flush on Monday..