How do I clean cylinder head surfaces?

[AGreedyTree]

I fixed the head gasket on my 1999 Buick Century last year but now it’s not sealing properly. Either I didn’t clean it good enough or it was warped. The head bolts were also replaced.

I’m going to fix it again. Last time, I used Fel-Pro PermaDry but this time, I’m going to use the PermaTorque. They don’t cost much more and they look better.

This time, I’m going to take the cylinder heads to a machine shop to make sure they’re perfectly flat.

What should I use to clean the mating surfaces? The engine block is cast iron but the cylinder heads are aluminum.

Topic

[yarddog1950]

You can ask the machine shop to “surface to clean”. This is something they often do as part of a rebuild.
If you don’t want to spend the extra few dollars to do this, you need to remove all gasket material and run your hand over the surface to see if you missed anything and check with a straightedge and feeler gauges.
In that it leaked on you, I would surface to clean.

[college man]

If the heads are aluminum I would have them checked at a machine shop for warpedge.
You could use a conventional gasket scraper. I believe they make spray on gasket remover
sold at most auto stores. a sharp razor blade in a holder will work also.

[dreamer2355]

+1 with the above posts. I wouldn’t use anything too abrasive on aluminum heads.

[Damien Hill]

If you are having the Head machined, you won’t need to clean the surface on that. However for the block, use a thumb sized piece of wet and dry sandpaper and gently work around the tops of the cylinders where the gasket seals. I find using your thumb works best for this. After your happy with the outcome, clean the dust off with a rag and use Mineral turpentine on the rag to clean around where you sanded. – Put some old rags in the oil passages and in the bores to help keep the dust out. But before bolting it all together again, just blast the bores out with compressed air.

[Mike]

I use a carbide scraper…works the best….just gotta be careful with aluminum

[AGreedyTree]

I was on another forum and heard Scotch Brite works good. So that’s what I’ve been using.

Would Mineral spirits be better than brake cleaner?

[EricTheCarGuy]

I’ve used an angle die grinder with roloc discs, you can use the course ones on the cast iron block but you’ll need the plastic ones for the cylinder head since it’s aluminum, I actually show what I use in the Caviler water pump videos, I use the same set up for cleaning cylinder heads.

I think it’s more important that you first find out if your head gasket is actually leaking by doing a block test, it’s actually quite common for those intake gaskets to leak causing coolant loss which can equate to an overheat. Also it’s VERY important that the head bolts get torqued correctly.

Cavalier videos

http://www.youtube.com/watch?v=WzNyk1lja2M

http://www.youtube.com/watch?v=Rw65VHVp7p0

Overheat video
http://www.youtube.com/watch?v=hUzOTnsWImI

Torquing head bolts
http://www.youtube.com/watch?v=5WHBskK_F3o

[AGreedyTree]

Thanks. I think that the reasons that the head gaskets weren’t sealing properly was because 1. the surfaces weren’t cleaned properly, 2. the cylinder heads were possibly warped, or 3. the cylinder heads weren’t torqued down properly.

I remember that when I was tightening the heads, the torque angle gauge kept moving even though I had that little arm out against a stationary part.

The Haynes manual said to use acetone and a rag to clean the surfaces. I remember that there was some gunk on one of the heads. It wouldn’t come off so I figured it wasn’t going anywhere.

I didn’t have the cylinder heads resurfaced but this time I am.

Hopefully I won’t have to do this a third time. This time, I’m going to pay more attention to the details and take my time putting the engine back together. At least I know what I’m doing this time. The first time I took the engine apart, it took about 2-3 weeks. The second time I did it, it took about 3-4 hours.

[AGreedyTree]

Since the heads are being machined, I don’t think I should have to grind them with surface conditioning discs. I’ll just wipe them down real good with some acetone and a rag.

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