Difference Between Blown Head Gasket And Intake Manifold Gasket Chevelle

Posted in Ignition Systems

Hey. There is coolant in oil, no oil in coolant. So as soon as I noticed, I stopped driving or starting it. Drained the oil (chocolate milkish), drained the coolant, replaced water pump and am ready to start looking what was causing it. The reason I am asking is because I really don’t wanna replace the head gaskets. It is all original (47K miles). Too start off, I make sure every cylinder is operating. Everyone has the pistons going up and down (blowing and sucking when finger is next to spark plug hole) and it is getting spark. I haven’t done a compression test on it yet. I will tomorrow as soon as I put new oil in there and have the bad one all out. The spark plugs are NOT wet and there is white smoking coming from valve covers (next to intake manifold). The heads aren’t cracked so I think it might just be my intake manifold gasket that is bad. It that is so, that would be great. So I don’t have to take off heads and all. What is the difference? Any help would be nice. Questions? Ask

There are 8 Answers for "Difference Between Blown Head Gasket And Intake Manifold Gasket Chevelle"

    1. David S says:

      The intake manifold gasket simply insures that you have good compression. Get ready to tear it down.

      It’s a head gasket.

    2. Alex says:

      Do you have water out of the tailpipe ? it sounds to me that its a head problem is water pressure building in your radiator ? it’s hard to say

    3. Blanoslap says:

      A blown head gasket will usually show bubbles in the radiator as compression gasses blow back into the coolant from the cylinder. You should see them with the engine running at temperature. The coolant escapes back to the oil pan when the engine sits and it leaks into the cylinders. The white smoke is the water vapor in the oil, it will come out the valve covers no matter where the leak is. You can start by removing the intake manifold and look at the gaskets to see if a spot is leaking coolant. It will be evident compared to the rest of the gasket seal. It could be a corroded water port or a head gasket.

    4. Baldie says:

      Run a compression test on it, that will tell you if the head gasket is leaking, but the way your describing it, it sure sounds like a head gasket.

    5. Old Man Dirt says:

      Lets face it, if you think the problem is the intake gasket, then take it apart that far at least.
      It seems to me from looking at the answers that a lot of those answering this question have never had an engine apart.
      When you get to where you can see the valley I am sure you will know if you need to go any further.
      Look at the gaskets as you take them off, hopefully you are right.
      But at that point you are only about two gaskets more away from having the heads off. So if you have the tools and skills why not just go ahead and get the whole thing done at once.
      I don’t think the work you will have to do will depreciate the value of the car (new gaskets can be bought that are exact duplicates of the original ones if you feel that it is required).
      By the way a lot of owners of these cars had the heads rebuilt every 40K miles anyway. (although I never would own one, I knew some owners that were serious about how to keep a small block in top running shape) It improves performance and also you might just want to up-grade the valves and seats to handle the no lead gas at the pumps now days.
      Good luck.

    6. Bit Pilsman says:

      A compression check should tell you quite a bit.

      My only problem with the intake gasket theory is that water runs thru there, but there aren’t any oil passages.

      It could still be sucking it in and pushing it into a cylinder. Is one of the tops of the pistons shiny?
      What motor are we talking?

    7. Roy D says:

      There is no water running through your intake manifold i think chevy rac has been snorting a little to many exhaust pipes

    8. Chevyraceman_383 says:

      For the one guy..

      We are talking V8 chevy here.. The intake sits in center of engine, above the lifter valley which is where the top end oil (heads) drains down into, then drains into crankcase.

      Yes an intake gasket leak can cause your probs. You have water ports on all 4 corners of heads.. If intake gasket is leaking at the ends then coolant could run into valley easy, and mix with your oil.

      Look over a few things to make sure before you start pulling apart..

      Fire engine up, and check your rad. over flow bottle, and rad.. Leaking head gaskets will tend to let cyl pressure into cooling system and will show as bubbles in the overflow and rad.

      Next with it running, does it smoke out the tail pipes.. What color is the smoke and what does it smell like?

      Blown head gaskets will send white stem out the pipes with a sweet antifrezze type smell.

      When you checked the plugs and if pistons was coming up, did your finger get wet, or did any mist blow out of plug hole? Thats a sign of blown head gasket

      Now remember with a blown head gasket, cracked blow or cracked head.. You don’t always have both (water in oil, oil in water)

      I have seen it happen where only water got into oil, or just the cyl and blew out the exhaust) Also seen just cyl pressure getting into cooling system and blowing upper rad hose off (no mixing of water and oil any where)