5 replies to this topic

[cleancutlawnservice]

I have 96 sonoma, with 4.3 vortec that I use as my work truck.

My intake manifold gasket has gone bad and is leaking coolant.

Would this gasket going bad also cause me to lose oil pressure? My oil pressure flutters/jumps while driving and then goes down to the red zone at idle. I hear a knocking or tapping noise when the pressure drops.

I have pulled the intake manifold off and just want to make sure I do everything possible to solve the oil pressure issue before I put everything back together. Any direction on where or what I should look for would be much appreciated.

The truck has had some overheating issues due to the cooling system failure.

Thank you for reading and any diagnostic help you can give me.

[cleancutlawnservice]

I just took my valve covers off and they are covered in a yellow water based cream substance which I am assuming is coolant. Do you know whether this is a result of the bad intake manifold gasket?

I drained my oil too, and it was like a milkshake too.

I am trying to determine if I have to replace my head gaskets. Please help, I'm stranded and so is my business.

Edited by cleancutlawnservice, 02 July 2009 - 02:04 PM.

[Draenor]

With what has been said, the over heating and loss of oil presure has probably warped the block and or heads. It is probably time for a rebuild or a new engine. I dont think replacing the gaskets would help. You'd have to tear the engine down and check the plane with a straight edge.

Edited by Draenor, 02 July 2009 - 02:09 PM.

[TexasAl]

+1

Take it to a shop that can inspect the head for you, and can resurface them if needed. If you go to a good shop, they can usually do it, or know where to take it. Might want to get the valve seals redone while you are at it. Good luck.

[green 788]

With so much coolant (presumably) in your oil, that might explain the haywire oil pressure issues. Since the oil was all foamed up, the pump would not likely be able to operate normally.

I think what it really boils down to is how much driving you did with compromised oil. If you drove the truck a lot, your main bearings probably crapped out (due to poor lubrication). That would explain your low oil pressure...

But if you didn't drive the truck too much in this condition... and you didn't drive it too far with the engine over-heated...

Then you might get lucky. You might replace the head gaskets (after checking to be sure the heads are not warped, and the block deck is okay, as mentioned above)... and put in good oil and all may be well.

I'm going to guess and say that if the heads are not warped, the block probably isn't either.

Good luck,

Dan

Edited by green 788, 03 July 2009 - 09:04 PM.

[cleancutlawnservice]

Thank you for all the responses, I have decided to go ahead and take the heads off and take them to a machine shop for resurfacing. Will update when i get it all back together.