I did a compression test on my motor (91 v8 5.2). I have 7 at 145 but 1 at 35 pounds. Whats my best solution? I mean I dont have the place to open the motor up. I have a parking out back of the house but its gonna snow at any time so, can I drive it another 6 months? Thanks

 

Are you sure 35. Is its 135? Because that is a extremly small number. I would think the engine would be seriously shaking if it was that low. If I was you I would recheck it. If it is 35 then you probaly got a problem with the valve. If it is a valve that wont be to hard since you dont have to completly remove the engine. You should do a leak down test to see where the leak is coming from.

 

First, what prompted you to check compression? (what was the driveability issue). I would assume a misfire, if you actually have one at 35 PSI.

Secondly, did you put oil into the holes or what? Because a new 5.2 of that year shouldn't see 145 PSI, let alone a 17 year old engine with how many miles? I would expect them to be 100-110.

My brand new 360 barely makes that, and that's with a moderate cam and 10.7:1 KB hyper's.

 

yea checked again and its 35 pounds. The engine is not shaking that much,just when its cold for 2 min. how do I do a leak down test?.

 

the bottom end of the motor was rebuit last year by the previous owner, so Im thinking maybe the guys at the machine shop did something wrong with that valve or cylinder?...i dont know, I never adventured in fixing motors or trannys before.

 

I did the test because I bought the truck 1 month ago and ther was engine oil that shot up on the hood. There was no cap on at the time but I still found that wierd that there was that much oil on the hood. The other reason is because its burning gas like crazy. Im always at the gas station.

 

With a differential cylinder pressure tester and a compressor.

 

Check out http://www.geocities.com/dsmgrrrl/FAQs/leakdown.htm