PDA

View Full Version : burning oil. did a compression check



brammabull69
06-05-2010, 06:31 PM
my jeep has been going through quite a bit of oil lately and its hardly leaking any at. i did a compression check and number 1 is 120 lbs, number 2 is 140 lbs, number 3 is 140 lbs, number 4 is 130 lbs, number 5 is 130 lbs, and number 6 is 125 lbs. those numbers seem kind of bad to me but what do you guys think? think I'm burning oil cause of bad rings or valve guides or something else? also my spark plugs are white and corroded looking and the electrode is melted at the tip. does anyone know what cause the spark plugs to look like that? thanks for any help.

albersondh
06-07-2010, 12:30 AM
Your compression doesnt look terrible to me especially if its high milage. Does it puff smoke at start up or if you keep it in 1st gear take off then deaccelerate, does it smoke on deaccelerate? These things will indicate valve seals/guides. When does it smoke?

Your plugs sound lean. Did they all look like shit or just one or two? Look for a crapped out injector. Do you have a CEL on? If your that lean I would think you would be throwing a code.

brammabull69
06-07-2010, 06:39 PM
i have no codes and it has 190k miles. it doesnt look like it smokes but on memorial monday i went wheelin and all the guys that were behind me could smell burning. all 6 plugs looked like that and i did some research and from what i found out it is preignition. the causes could be to lean or to advanced of timing but you cant adjust those. it also said that spark plugs that have to high of a heat range will cause it so im gonna change them first

albersondh
06-08-2010, 04:31 PM
Is that leak a rear/front main, that would get much worse off road compared to normal highway use. If its not smoking it, it has to be leaking it. With that kind of milage it wouldnt suprise me at all that you would be burning 1/2-1-qt per oil change, just due to milage and wear. While you have the plugs out it would be a good idea to use some combustion chamber cleaner in there. It will help free up sticky oil rings that could be contributing to oil burining. Also it can help with ignition problems by cleaning off carbon deposits that become hot spots and cause detonation. I dont think it was detonating because that should throw a code (mis-fire). Be sure and change the oil right after you use the combustion chamber cleaner.

If you think your lean and thats causing detonation issues, you should have a lean code. Can you read O2 voltage, or have access to a scan tool, have a friend that works at a dealership?? Check fuel pressure at the rail make sure its within spec (thinking lean still).

Its risky but you could always run a qt of dextron in your engine oil for like 10min while it idles, just before you change the oil. This will help clean shit up, but if its realy gummed up, it can free enough shit to clog an oil passage. I do this about once a year, but I started doing it before 100k miles to....

I doubt your plugs are out of there heat range. The only reason to do that would be if you were on boost, higher compression, or had access to shit gas only. When was the last time you changed the plugs?? Maybe there just verrrryyy old. What I would do.


- Check fuel psi at the rail
- Fix all oil leaks.
- Combustions chamber cleaner
- 1qt dextron in the oil for 10min at idle
- New plugs, cap/rotor (check wires for 10K-ohm per foot, replace as required).
- Check coil condition by jumping spark to ground (should be white/blue, not red/orange).
- Run some good injector cleaner
- Run some good oil (I like Rotela-T) mixed with a couple qts of Lucas.

Thats what I would do, see how that shakes out then go from there..... This post should be in the repiar shop section.

brammabull69
06-08-2010, 10:25 PM
ok, thanks for the ideas.