Hi
I am new at this forum and have a question about my 2000 Silverado with 5.3 Vortec.
Just bought it used to find out that there was coolant in the oil.
Bought a gasket for the intake to find out that is a dry intake and therefore can't cause the problem.
I assume it will be the head gaskets.
Is their a way to find out easy, and how hard is it to replace those?

Ben

 

Hi bigben,

Welcome to the Chevy forums.

There's three possibilities. 1)Blown head gasket 2)Cracked head 3) Cracked block

Hopefully a compression test will localize the damage, if it's 1 or 2. Once you've found the problem area, you can try replacing the head gasket, and inspect the head for damage.

Google "Zyglo dye"

 

You might try pulling the spark plugs. If it is just one cyl. giving the problem, it may show just on that plug.

 

Thanks for the fast reply.

I allready pulled the plugs and they are all looking oily.
It's hard to do a pressure test since I allready have the intake manifold off (was going to replace the gasket) and also have the waterpump off to replace it's gasket.
Don't like to put it back and take it off later on, to pull the heads.

 

might as well pull the heads then. if you already have some of the stuff off.

 

there is a tsb on some of the cylinder heads, i think they have a casting mark on them that resembles a small AA battery, I worked on a truck that kept "loosing" coolant, i replaced the heads and it quit, the cracks were very hard to see

 

i think that i am running into the same problem. truck makes a knocking sound upon start up and the noise dies out. took it to the dealer and they said it was probably the head was cracked. i am going to tear into it in a day or so to see what it is. its using coolant and the oil is sludgy. i was also told the same thing about the heads having that mark and that problem. i will probably replace them with gm parts and hopefully that will solve my dilemma. i have also heard that having coolant and oil mixed in the crankcase can cause it to spin a bearing... is that true? come on guys, gotta help me

 

I pulled the heads and the casting mark wasn't the one I feared.
After cleaning the heads I replaced the gaskets and it works like a charm now.