I have a 1997 blazer, it runs with a slight stumble. It has oil milk shake in the air box. I would think this is a intake gasket or do you think it is a head gasket. Any ways to test either way? Thanks jamie

 

How in the world did oil/coolant get into your air box???

How does the oil in the crankcase look? Have you tried to do a compression check on each cylinder? If you have good & consistant compression on all cylinders, then your headgaskets are mostlikely fine. If you find that one cylinder has low compression, try squirting a shot of oil into the cylinder and cycling it a bit with the starter. Then recheck the compression. If it jumps up, then you have worn rings.

If you do have a head gasket problem, then you may be able to see bubbles in the radiator (if it's full) when the engine is running.

 

Compression test and a leak down test are the first tests you should do. You can also do a simple block test to find out if you have exhaust gases in your coolant. You can buy the kit from NAPA or find a shop that does it. It only takes about 2 minutes to do.If the heads are the problem, make sure you have them magnafluxed to check for cracks. They can crack around the seats and into the water.