Cracked Block or Cracked Intake Manifold

[Pakaskas]

I have an 89 240SX KA24E. 130KI have a slow water leak into the oil.I took off the head and replaced the head gasket and had the head machined and tested. The old head gasket was in pretty good shape. While I had the head off I replace the timing chain, intake man gasket, exhaust gaskets, etc. The only bad gasket I would suspect was the intake manifold gasket, because I saw corrosion between the water inlet and the #1 cylinder intake port. At any rate, since I replaced that gasket, I thought it would solve the problem. I put everything back together and the car started fine. I ran it for a few days and I started losing water again and now I am starting to notice water in the oil. No noises and no external leakage. When I start the car, I have a lot of steam, not smoke, until it warms up. I would think if it was a cracked block, it would be leaking externally. I am suspecting maybe a cracked intake manifold? I think my first step will be to pull the timing chain cover off and make sure the inserts going to the block are sealed ok. But I am thinking of pulling the intake manifold first. Not sure how to test it. Any advice?

[yellow_jacket]

Look for a spot in the front cover where the chain might have eaten through it. Or maybe the front cover just cracked.

A cracked block will not usually leak externally. And steam coming from your exhaust is normal when it gets cold outside. Antifreeze smells sweet when it burns so it is fairly easy to smell it in the exhaust.

I doubt the intake has anything to do with it considering there are no oil passages that the coolant to flow to from the manifold.

[Pakaskas]

Thanks, I will check the front cover. When I took it apart before, the entire timing chain guide was gone and the chain had started to eat through the bolts that held the guide on. Not sure where the guide went, although I suspect what is left of it is in the oil pan somewhere. The timing chain tensioner was in fair shape, but I replaced the tensioner, timing chain and guide. I need to take a closer look at the cover though and see how the water flows through. I read an article that said Nissan says you can remove the front cover without removing the head, so I am going to give that a try. One of the reasons I was suspecting the intake manifold is that a co-worker of mine said he had a cracked intake manifold. You are right about it getting into the oil. But I thought that it could have leaked down through the piston rings. Anyways, if it turns out to be a cracked block, I will probably replace the entir engine and transmission. The transmission has had problems the last few years also.

[Pakaskas]

YellowJacket,You were right. I pulled the front cover off and carefully inspected it and found that the chain had worn a groove into the front cover water jacket, when I put my finger on the inside, you could feel where the chain had eaten through. So now it is a matter of replacing the front cover. I took the front cover off without removing the oil pan or the head. Anyways, thanks for your advice.