Coolant and oil are mixing...

[JRD761]

I've got a 2004 Silverado 1500 with the 5.3L V8 engine and around 85,000 miles.

I've noticed over the past couple weeks that my coolant level keeps getting low.
I'll top it off, then in a couple days, it's back to where it was.

I don't notice it leaking anywhere. There are no drips in my driveway, I don't smell burning coolant, and I don't notice anything leaking from anywhere.

Today I checked it out a little better. I pulled off my oil filler cap, and in the plastic tube that comes from the valve cover to the oil filler cap there is a bit of cream colored sludge.

I changed my oil around 2,000 miles ago and none sludge of this was there...
I checked the oil level on the dip stick and it looked fine.. the oil didn't look dis-colored or anything, and the level is just fine.

I started up and couldn't tell if its smoking or not.. it's pretty cold out here and all cars tend to let off a little steam or something that looks like white smoke when its cold, so I can't really tell if it is smoking or not.

The truck does not overheat at all.. just sits at it's normal temperature and never goes over or under it.

What do you guys think? Some people have told me that it could be a bad intake-manifold gasket, but I've always thought that cream colored sludge meant a head gasket..??

[farmtruc]

intake gaskets don't touch the coolant so...

if anything, a head gasket, check the plugs and see if one looks cleaner than the rest.

[JRD761]

That's what I'm looking at..

[Frenchy]

Could be the castech heads. A lot of castings were faulty. There is a TSB, take it to the dealer have them run your VIN see if you have these heads. The General will replace them if you do.

[JRD761]

I saw the TSB and was concerned this could be the problem as well..

Do you think GM will since it is a 2004, I am the second owner, and its at 84,000 miles?
Anyone tried it or heard of it being done?

[Frenchy]

They should.

[oleshifty]

if it's just that tube..i wouldn't worry too much. Most of the ones I see do that. I know my silverado/tahoe/blazer all look like that. The gaskets can leak, and moisture settles in there. Loosen drainplug and drain a little. If that's cream, head gasket. Normally vehicles idle very rough, and overheat when this is the case.

[JRD761]

I haven't gone further into the motor.. I plan on taking the valve covers off tomorrow and seeing what I can find. It's just what I see in the oil filler tube and the fact that I'm loosing a bit of coolant every couple days and it doesn't seem to be on the outside of the motor..

[oleshifty]

Mine does it when it's cold. From october to april i lose the capacity of the reservoir. I just kinda brushed it off to heating/cooling to extreme conditions, and leave it alone. It's done it 3 years now, first 2 years drove me nuts.


What's 'a bit' of coolant?

[JRD761]

It's probably been a half a gallon so far this month..