I have a 2000 Chevy Blazer with about 92k miles on it. Last fall, when I turned on the heat for the first time it blew cold air. I took it into my repair person and he checked my antifreeze, which was empty. After he put antifreeze in, the heat kicked on and worked ,but he told me there might be a problem and I should watch for leaks. Well, I didn't notice anything during the winter ,and I had an oil change February. They told me then that I had fluid, most likely antifreeze, in my oil. They flushed me out, changed my oil and put in new antifreeze and things seemed fine. I just went today to have my oil topped off (I am not at 3k miles yet for an oil change) and they told me today that I have antifreeze in my oil and that it is most likely a cracked head gasket or leaky intake manifold gasket. Does this sound right to you guys? If anything it would seem to be a slow leak because I still had coolant from the last time they filled me up in February. How much damage do you think this has caused my engine, and do I need to look into getting a new one?

 

Anytime coolant gets into oil it's guaranteed head gasket or manifold gasket as they said. To the best of my knowledge anyway.

 

Now question is which antifreeze did you use. Are you using the old green antifreeze, then it's not so bad. The dexcool stuff will cause more potential problems. That stuff has a tendancy to cause more corrosion and wear seals more.

But either way, depends on how long it's been leaking into your oil. The antifreeze breaks down the oil's ability to lubricate and can cause the main bearing to fail. Also the main seal could be damaged. If you don't have any oil leaks that should be ok. But you'll definitely need another complete flush (especially if you use dexcool). And have the gasket replaced. A manifold gasket is not as bad as the head. Less to take off to get to it.

 

For more than you ever wanted to know about Dexcool, check out the WHO'S HAD GOOD LUCK WITH DEX-COOL thread since it is already an open discussion on coolants and their merits.

About your problem, I would say that it is very likely that your intake manifold gaskets are at fault. You can pull your plugs and look for signs of steam cleaning as would normally be found if water were getting into a cylinder or two. You can also run a compression check on each cylinder and/or do a coolant combustion by products test to see if your coolant has any by products of combustion in it.