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I have a 98 saturn Sl2 drove it to part store today about 1.5 miles did a compression test I got 175 195 190 198 tested th first one 3times wet test was 200 210 210 210 then started it burned all the oil out about 4mins then tested again 3 times and got 203 202 200 201 waited 20 mins did it again 3 times and. Got the same numbers. After the wet test I made sure after I ran it to check and make sure the cylinders were dry . Cars runs good. Used oil but I wanted to just check the engines health it has 195,000 miles. Any idea what would cause the inconsistent numbers? Thanks for the help. Greatly appreciated
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You had it at WOT (wide open throttle) when doing the test right?
If the engine was still warm when you did the test the 2nd time the rings probably expanded a little bit so they were sealing better wich = higher compression plus the oil probably help loosen them up a bit.I have to agree, those are great numbers for a car with 200k miles. I wouldn’t sweat it. The low cylinder could have extra wear on the rings, or a valve that has a slight leak, but again, I would let it lie.
Yes done at full throttle. I didnt however let the car run without fuel pump relay Until it died. While the car was shut off I just unplugged it and started the compression Test. Is it possible that the first test the rings were fuel washed a little bit maybe?
Quoted From dakota1820:
Yes done at full throttle. I didnt however let the car run without fuel pump relay Until it died. While the car was shut off I just unplugged it and started the compression Test. Is it possible that the first test the rings were fuel washed a little bit maybe?
Yes! That is very possible.
That’s a good possibility. Did it cough black and blue smoke when you first started it? That would be the oil and excess fuel burning out.
Quoted From Beefy:
That’s a good possibility. Did it cough black and blue smoke when you first started it? That would be the oil and excess fuel burning out.
Haha, I think we were typing at the same time beefy.. 😛
It was just grey mostly. Mind you at the time i wasnt analyzing the smoke as close as I wish I would have. It just didn’t make sense that dry it was 175 then wet 200 and after letting the oil burn off it was 203 and then letting it sit for 20 minutes after all of that it was still at 203 unless it was fuel washed or not completely warmed up?
Did you ever start the car in between the sitting periods? If not, the cylinder walls would still be wet with oil. Even if you did, it sounds like you washed the cylinders down with fuel before the initial test, and the oil replaced the fuel, creating a good seal. Regardless, it sounds like you have great compression, and you said the car is running fine. I think you are making a mountain out of a mole hill honestly. Just enjoy the fact that your car is running good 🙂
Never started it after clearing the cylinders of oil after the wet test. I did however crank it over in between test to make sure the rings were free of oil. I originally started this whole event because it uses a quart of oil ever 600 miles. Maybe it just oil control rings? I did yesterday start it up from dead cold and floored the go pedal it smoke blue smoke after 10 seconds it was done and wouldnt smoke again. Today did the same thing and it didn’t smoke at all. What gives? Pcv valve is good there isn’t oil all over the plugs either. Im confused I do know flooring it at cold start isn’t good but I did it for diagnostic reasons. Besides that I take better. Care of this car than most people take care of a new car
Hrmm… You have good compression test numbers, but you are losing alot of oil. Are there any obvious oil leaks? Do you leave puddles when the car sits overnite for instance? You could have a bad head gasket. What does your coolant look like? Lemme find you a video.
Eric’s vid on overheats, which includes block testing:
http://www.youtube.com/watch?v=hUzOTnsWImI
I do find it odd that you aren’t having a smoky exhaust, which Saturns are famous for. If you aren’t burning oil, it’s got to be leaking. Oil doesn’t just disappear.
The oil may seap. I say may because where the transmission meets the engine it has a brace. That goes around the side of the oil pan. But it. You cannot. See the oil pan on the side because of the brace. But its on the side where the oil filter is and it very well could just be from installing and removing of oil filter. It doesn’t leave any marks on the ground I’ve covered the underneath of the car with cardboard let it run for 30 mins and then sit overnight not a single drop. The valve cover did seep. But I fixed that recently. Engine was very clean to. No sludge or varnish at all. 🙂
Coolant is also fine doesnt use any and its clean. It doesn’t have a bad head gasket. I’ve had the car 9 months when I bought it it used a quart of oil every 300 miles piston soaks new pcv etc. Have made it bette. But still bad. I imagine either valve seals or oil control rings are bad ….or both
It does run great. I was more concerned with the inconsistant readings. And the. 175 reading. Service limit is 180.
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