no compression

[lamb140]

I have a 94 metro and it has been a great car but now its missing really bad. I did a compression check on it and the numbers are as follows.
From left to right starting at the cylinder by the timing belt here is the bad news. 125 psi w/o oil, 135 psi w oil--- 135 w/o oil, 140 w oil
and then the last cylinder has 0 psi w/o oil and o with oil. There is hardly any blow by and believe it or not it will still run 80 mph.Does it sound like it has burnt valves or something more drastic wrong with it? The Engine is only supposed to have about 70,000 miles on it.

[pind]

It is sounding like a burned valve, no compression with oil means that chances are its not blowing by the rings. Now, what you can do, is make and adapter to put compressed air into the cylinder, and listen for where it leakes, if its into the exhaust, bingo, valve issue, and it does not take much of a burn to cause 0 compression.

On the happy side, you can replace one valve, as usually the seat is ok. By this, I mean that I have seen valves that are literally little melted nubs on the ends of the valve stem, and the seat is still fine. Get a new valve, lap it in with some proper valve grinding compound, a new head gasket in the mix, and you should be good to go, bing bang boom.

Good Luck, and happy motoring ( puttpputtttppppuuutttt off into the sunset.)

[datalore7]

Hey if this was my car I would do all the valves to be on the save side I had the same thing happen to me I but one in and about 5 months later I had to do it all over I hope that I help you.

[Mac1947]

Do all of the valves, get it done right and be done with it for many smiley miles to come.