Those dealer mechanics were complete idiots and probably just wanted to take your money.
Every dealer knows these motors are prone to head gasket failure because the factory thermostats that were originally installed were causing these motors to run way hotter than they were designed to.
They know this because the manufacturer issued a TSB years ago, and almost every one of these engines that didn't have these replaced ended up blowing the head gasket.
Also, it's easier to check for a blown head gasket than it is to replace any one of the parts you've already replaced.
All you need to do is pop the top of the overflow tank (While engine is cool). Then start your engine. While you have someone push the accelerator, look inside the coolant.
As the engine revs up to about 1,500 rpms, you'll see large bubbles coming up in the coolant.
And don't bother putting another dime into that engine. You money will be better spent finding a used engine with 50,000 miles on it and having it installed.
Make sure you trust the mechanic and he/she tests the used motor to make sure it doesn't have any pre-existing problems.
Also, make sure to put the thermostat in that GM recommends or you'll blow that head gasket also.
Thursday, September 9th, 2010 AT 5:51 AM