Deon writes: I have a 1999 Yukon with a V8 and 112k miles. I have to add a pint of coolant every other week, but I can’t find a leak. Where could the coolant be going? Also, since I keep adding coolant, do I still need to flush it?
Deon, GM V8s and some V6s have a problem with leaking intake gaskets. They seep coolant, which evaporates when it hits the warm engine and that is why you don’t see a drip. I guarantee you that when you look on the backside of the intake, you will see the corrosion stain from the leak. On your Yukon, it’s not if you will have a leaking intake, it is WHEN you will have a leaking intake. Replace it with one from Fel Pro, they are metal instead of plastic and are a permanent fix.