hey so I have a question I have a 2000 gmc jimmy the rad was replaced when I bought the truck. im running the green coolant and not the crappy dex cool gm uses. lately I have been filling up my overflow tank a lot and im wondering if my intake manifold gasket is leaking. I have no leaks or drips outside the truck and my engine oil seems fine with no coolant inside it could it be a head gasket or intake manifold gasket. my heat sits around 90 degrees at all time

 

Run a coolant system pressure test and you'll see where the external leak is.

 

my friend said that to me as well my frost plug looked iffy but didn't seem to be leaking. ill see how much it cost to get one done I don't wanna ruin the engine. im onto 272 000 km and haven't had a single issue with the engine always maintain it and run synthetic oil only had to replace a sensor