#105681, "Smoking and low compression" Aug-15-07 08:18 AM by Fallen4ng31
I'm pretty new to the scene, and to cars in general. I recently purchased a 98' RS with approximately 80k. A little less than 3 weeks in, it started smoking blue from the tail pipe. (I don't rod the hell out of it or anything)It's burning about a quart of oil every 180 miles, yet it doesn't leak onto the ground. I checked the plugs, they haven't been fouled, replaced anyway. The PCV valve is completely congested with oil, changed it; same deal. Took the thing to a couple of mechanics, but they want around $600-$800 just to tear off the head and search for the problem. One did a compression check; Cyls 1&2 - 140, Cyl 3 - 138, Cyl 4, I don't remember but it was around 140. Any thoughts here? (Try to remember my mechanical knowledge is limited) Many thanks in advance!
P.S. If this thread is in the wrong place, let me know, I won't make the same mistake again.
#105682, "RE: Smoking and low compression" In response to Reply # 0
Were those compression numbers done hot or cold? Did they try a wet test as well? What were those numbers?
Your compression is very low.
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'95 Eclipse TurboGS (garage deco) '95 TSi AWD (restoring a survivor) '97 Talon ESi-T (poor impulse control) '99 Eclipse RS-T (daily beater) '13 Evo X (mostly stock) '17 Sienna (Middle Aged Dad Mobile)
#105684, "RE: Smoking and low compression" In response to Reply # 2
Buy a compression tester from you local autoparts store and re-do the test yourself. They're only about $30. Perform the test with the engine at operating temp. After the initial test, add a capful of oil to each cylinder and re-test for the wet test. Post those numbers and we can give you a good idea of where to start.
______________________________ If a sentence found online has 35% misspellings or greater and includes at least two racially charged expletives, chances are it is a YouTube comment.
'95 Eclipse TurboGS (garage deco) '95 TSi AWD (restoring a survivor) '97 Talon ESi-T (poor impulse control) '99 Eclipse RS-T (daily beater) '13 Evo X (mostly stock) '17 Sienna (Middle Aged Dad Mobile)
#105720, "RE: Smoking and low compression" In response to Reply # 4
sounds like dead rings or headgasket, definitely get the car to full operating temp (drive a few miles minimum) and don't shut the car off till you're ready to test. start with no oil, pull all the plugs and hold the throttle open. test all cylinders. if it's still low, put the cap of oil in each cylinder right before you test it and get new #'s if the compression goes up, time for a full rebuild or fresh block (I had this problem) compression stays the same, headgasket or valves are toasted, fix accordingly
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#105768, "RE: Smoking and low compression" In response to Reply # 5 Aug-19-07 11:16 AM by Fallen4ng31
Ok, so I did a compression test myself. Cylinders 1-4 tested at: 190,200,205,210, respectively. The initial compression was much lower. It was only after 5 or 6 full cycles that they reached the listed numbers. The initial compression for each was around 120 on the first crank. After the wet test those numbers all increased to around 230 on each cylinder. Would I be justified in assuming I need new rings? Or should I save myself some serious headaches and just buy a new engine?
BTW - Have I ever mentioned how poorly written and illustrated Haynes manuals are?
#105770, "RE: Smoking and low compression" In response to Reply # 6
Originally posted by Fallen4ng31 Cylinders 1-4 tested at: 190,200,205,210, respectively.
As a rule of thumb, your lowest cylinder should be within 10% of the highest. In your case, 10% of 210 is 21psi, so your lowest cylinder should be about 191psi. Not bad, imo.
I believe the compression will go up once you add in the oil, regardless of the condition of your rings because the oil is a better sealant than the rings before it's burned off. So your going from 210 to 230 with the wet test leads *me* to believe your rings are still pretty good, however the greater the difference between the dry and wet numbers, the more likely it is that your rings are getting tired.
A better example of blown rings would be like my Galant right now. I pull down 70psi dry and about 225psi wet. Just to give you an idea.
Does the smoke happen after extended periods of idle? Such as in the drive thru or waiting for a train to cross? Smoke more at idle that goes away under loads is generally indicative of valve seals.
#105772, "RE: Smoking and low compression" In response to Reply # 8
Oddly, she smokes very intermittently. Sometimes at idle, sometimes when my foot is on/off of it. Sometimes at startup and sometimes at operating temp.
#105775, "RE: Smoking and low compression" In response to Reply # 9
well if you let off the gas and smoke comes out the tail pipe that would be bad valve guides,if you performed the wet and dry test and the numbers stay the same your rings a5rent the corporate.tear it down for a visual inspection and see where your at from there
#105776, "RE: Smoking and low compression" In response to Reply # 10
Unfortunately, this is not a viable option. For starters I lack both the facilites and the know-how to undertake such a task. Secondly, it's my daily driver, so keeping it o.o.c. for any length of time isn't an option either.
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