Coolant on pulled spark plug, cause/repair options?

[R1ckM]

I am replacing the head gasket on a m20 engine that had some oil in the coolant system but no coolant in the oil.

However I now am down to the head and pulled the spark plugs out so I can make sure the timing is aligned 100% before I pull the head off.

Cylinder #1 spark plug has some coolant/watery mixture on it when I pulled it out. The rest of the cylinders/plugs were coolant/water free and looked normal.

I plan on replacing the head gasket, timing belt, water pump, cam seal, crank seal and valve cover gasket.

Dropping the head off at the machine shop so they can clean and inspect it before re-install. I will check the block, piston and cylinder walls for any issues.

Should this take care of the issue, what is the cause of some coolant in one spark plug hole/cyl?

[jeffnhiscars]

Blown head gasket between a coolant passage and the cylinder or a cracked head. Mention that to your machinist so he takes care to check

[R1ckM]

Blown head gasket between a coolant passage and the cylinder or a cracked head. Mention that to your machinist so he takes care to check

Alright, yeah I am hoping thats it. I will specifically mention it to the machinist as well.

I also have a related question as well.

The underside of the valve cover, there is a layer of thin sheet metal riveted and centered to it. One of the corner edges are bent just a little, theres no crease in the metal its just bent up slightly but I noticed the other corners weren't.

I tested another edge and they seem to want to flex and bend easily. I assume this isn't anything abnormal or going to cause an issue?

[jeffnhiscars]

As lone as nothing hit it and the bend isn't a fracture that could fall off a wreak havoc, you should be fine. It's just a splash guard.

[ForcedFirebird]

Most likely warped head. When the m20 heads crack, they mix coolant into the oil.

Make sure your machinist doesn't shave the head less than 4.909" total height (measured from valve cover surface). If it's warped excessively, have it heat straightened before milling or you run the risk of your camshaft binding in the bores.

[R1ckM]

Most likely warped head. When the m20 heads crack, they mix coolant into the oil.

Make sure your machinist doesn't shave the head less than 4.909" total height (measured from valve cover surface). If it's warped excessively, have it heat straightened before milling or you run the risk of your camshaft binding in the bores.

To my relief the machinist was familiar with m20 engines and heads when I dropped it off. He said he had experience with them.

That makes me feel a little better long as he knows what hes doing the right way and not generalizing.
I'll be sure to go over details with him to make sure they all match up to what you all are saying.

When I first looked at the head and block after pulling it off, I looks as though the top right gasket area around cylinder 1 got some oil through and into the coolant holes. We'll get it worked out either way. I just don't want to waste my money on parts if the head and block aren't right.