Bad compression

marklar · Post by **marklar** » 21 Apr 2014, 13:15

I did a compression test today and got 120-120-120-120-90, is there a simple fix to this or is it time to sell? I did a wet test in cylinders 1 and 5 and got 150 & 120, so it was bad even wet. I'm not going to lie, I'm pretty upset. But at least I didn't start putting anything into it and now I know how to do a compression test (thanks rspi). Your thoughts and condolences would be appreciated, lol.

Post by **JDS60R** » 21 Apr 2014, 13:45

This or new/rebuilt motor.

Post by **alschnertz** » 21 Apr 2014, 14:13

I just did the same thing yesterday and had virtually the same readings on my '95.
It is a bummer. I like the car but probably not enough to spend the $ on a rebuild.
Sigh.

Post by **abscate** » 21 Apr 2014, 17:13

Is it running well with decent fuel mileage ? Before you totally panic the fact that they are all close is good. That's more diagnostic than the actual readings.

There is always a possibility your instrument is bad and you real compression is higher and your engine is in good shape. Was your battery fully charged and did you have all plugs out and throttle plate open ?

On edit..I missed that 90 on the end. Ugh.

Post by **Ozark Lee** » 21 Apr 2014, 17:26

Sometimes you can improve things with a Seafoam treatment. It is fairly cheap to try it and watching the giant smoke cloud after the top end treatment freak out my neighbors is kinda fun anyway.

I am similarly situated with my '94 except my 90 PSI cylinder is number 1 and I've tried all of the miracle in a can products to no substantial improvement. I really like that car even though it has around 280k on it and at some point I will probably drop a new engine in it.

...Lee

marklar · Post by **marklar** » 21 Apr 2014, 17:30

I bought the compression tester today at harbor freight, all the plugs were open at the same time, what do you mean by the throttle being open? I'm not sure the condition of the battery but its starting good and the mpg is pretty decent, around 24 in town

Post by **alschnertz** » 21 Apr 2014, 17:42

Hmmm. I did forget to hold the throttle wide open. I wonder how much difference that'd make.
My readings were 115, 125, 125, 125,125. All bumped up about 25 psi with oil in the cylinders.

Generally, the car runs pretty well. Does burn some oil though - about a quart every 700 highway miles or so. I had thought it was valve seals, but now figure it's a combination of rings and valve seals. Gets around 22 mpg in town on 10% ethanol fuel. Yea, it's a tired engine. It's too bad because the body is excellent and just about everything works.

For now, I'll keep running it. I figure a rebuild would probably run around $3,000 - $4,000 or so and I just can't swing that right now. Is that accurate?

marklar · Post by **marklar** » 21 Apr 2014, 17:45

I had my foot to the floor on the gas pedal

Post by **erikv11** » 21 Apr 2014, 19:56

alschnertz wrote:... Gets around 22 mpg in town on 10% ethanol fuel. ...

That's great for city miles, keep driving it!