What is good Compresssion on an SE?

[philip5]

When I purchased my 1989 SE last week, the test showed a solid 155 on all four.

[wcdeane]

I have a '91 SE with 28K miles on it. My compression is 145# across all four. I am told that 140# is spec. A measure of 155# might indicate a little carbon build up. Carbon build up in the combustion chamber increases the compression ratio. Eventually, that will start working against you. Generally speaking, the benefits of boost deminish as the compression ratio goes up. You may want to consider carbon blasting additives in your fuel, or maybe water injection.

[philip5]

Any advice on which additive to use?
Thanks

[cnh1990]

If it is rock solid 155 across the 4, it could just be a deviation of the gauge.
Calvin

[wcdeane]

Calvin is right. I could just be the gauge. You could try borrowing someone else's gauge, and see what kind of readings you get.

As for an additive, I don't have a suggestion on hand. It has been too long since I've had this sort of problem/concern. However, I would think that a good parts house would be able to offer a suggestion, if you want to try that sort of thing.

Cheers