Bad intake gasket?
 

Hello everyone, I have a 1989 K1500 tbi 5.7 w/182,000 miles. My truck has sat a lot over the last 6 months, only going on short trips so when i found moisture on the dipstick I wasn't too worried. I changed the oil, replaced valve cover gaskets (which were clean inside), oil pressure gauge and cleaned the pcv system thoroughly. Today I drove it 60 miles and now there are actual white globs on the dipstick, but very little. Oil pressure read normal. I was hoping 60 miles at highway speed would burn off any moisture. However, it's also not burning much coolant, if any. When I got it home, the radiator was still full, and overflow level hadn't changed. Also, after driving today I noticed oil pooled around the middle 2 pass. side intake manifold bolts. I think I'm going to pull those bolts and put some thread sealer on them and make sure they are torqued correctly. I'm also considering a coolant pressure test. From what I've researched, an intake gasket failure could explain the small amount of coolant in the oil, and also explain the oil pooling on top of manifold. I know there's a lot of info on this topic but was wondering if there was anything else I could check to indicate bad intake gaskets, vs. head gasket failure. Thanks in advance

Well, The coolant pressure gauge has been on there for 1 1/2 hours and it's lost 4 pounds of pressure. I'm thinking I might pull the plugs while the pump is still hooked up to see if the pressure suddenly drops or anti freeze pours out.

Pulling plugs didn't affect pressure. I let all the pressure out of pump and started it, ran it a few minutes and pressure didn't increase on the gauge, which I think is good.

You are wasting your time. The truck isn't getting warmed up enough to burn off the condensation in the crankcase.


Take it for a 50 mile drive.


Allan

I took it 60 miles today, but I did stop halfway for over an hour. I hope you are right, I'll take a drive up the mountains tomorrow. She's been well maintained, new oil twice a year and I've only put 30,000 on since I got her 8 years ago. Just don't like milky oil. I haven't seen that during winter yet with this truck. Hopefully I just need a dipstick that seals proper.

Well, when I found a nasty smelling white-ish milkshake on my 1989 Ford E-150 van it is either head gasket or cracked head or cracked block - so I bought a 96 GMC Yukon. I also have a 97 Silverado sitting in my parking lot that has a bad intake manifold gasket - coolant and oil don't mix on that truck it just blows white smoke.

I'm sorry to hear that. That's never a good sight! Is your 97 a vortec?
I drove my truck 100 miles today and it didn't get worse, or better. I think at this point I just have to keep an eye on it. Worst case, crate engines are cheaper than new trucks.

Both my trucks have the "vortec" 350.

A new truck is $40-60K. A new crate engine is expensive compared to the used trucks this age, but still much cheaper than a new one. Heck, a new engine and transmission still saves you a lot of money :)

How were you able to nail down that the problem was the intake gasket on your truck? I think after school today I'm going to try to read any codes the truck throws. The check engine light is coming on now on the last 4 trips I've made, which I've never seen on this truck.
I've found used Chevys for the price of a crate, but I'd rather fix mine then buy someone elses problems, if it comes to that!