Cylinder 4 missfire along with burnt oil smoke
Tal92on
01-03-2009, 08:30 PM
Ok so, for the past month or two ive had a problem that i just cant figure out. So here it goes, if any of you out there may have ideas or possibly know a fix it would be greatly appreciated.
The problem started with a misfire on cylider 4, and 4 only, followed by excessive burnt oil smoke comming from the tailpipe. An idea for the smoke was blown seals on my stock turbo but that wasnt it, and that doesnt make sense for the missfire portion. When its running you can unplug the cylinder 4 fuel injector connection and it doesnt affect how it runs at all, as well as pulling the spark plug wire. The ISC, TPS and Throttle position switch all also dont affect how it runs at all when tampered with. I removed my valve cover to make sure a rocker hadnt fallen off or possibly a lifter collapsed and everything looked good. I followed that with doing a compression test, this is what i got CYLINDER 1-(152) 2-(155) 3-(155) 4-(158). Id say thats pretty good. So i moved on to other things...I tried a different resistor pack for the fuel injectors, ive tried a swapping out a whole different set of fuel injectors, a different coil pack, power transistor, sparkplugs, sparkplug wires, mass air flow, multiple ecu's. I thought it may have been the 4th cylinder fuel injector stuck open but i was wrong, i Ohm'ed out and voltage tested all the connections for the fuel injectors when the car was running and they were all equal. I then took off the exhaust manifold and the ports of cylinder 2 and 4 were wet with oil, 4 much worse than 2. Could it be a blown headgasket? Im a little lost because that still doesnt make much sense to me for all the Sensors having zero affect on how it runs. I mean this thing runs absolutly horrible, idles at -5vaccuum and smoke pours out the exhaust.
If you have any ideas please send them my way, thanks -Sean
The problem started with a misfire on cylider 4, and 4 only, followed by excessive burnt oil smoke comming from the tailpipe. An idea for the smoke was blown seals on my stock turbo but that wasnt it, and that doesnt make sense for the missfire portion. When its running you can unplug the cylinder 4 fuel injector connection and it doesnt affect how it runs at all, as well as pulling the spark plug wire. The ISC, TPS and Throttle position switch all also dont affect how it runs at all when tampered with. I removed my valve cover to make sure a rocker hadnt fallen off or possibly a lifter collapsed and everything looked good. I followed that with doing a compression test, this is what i got CYLINDER 1-(152) 2-(155) 3-(155) 4-(158). Id say thats pretty good. So i moved on to other things...I tried a different resistor pack for the fuel injectors, ive tried a swapping out a whole different set of fuel injectors, a different coil pack, power transistor, sparkplugs, sparkplug wires, mass air flow, multiple ecu's. I thought it may have been the 4th cylinder fuel injector stuck open but i was wrong, i Ohm'ed out and voltage tested all the connections for the fuel injectors when the car was running and they were all equal. I then took off the exhaust manifold and the ports of cylinder 2 and 4 were wet with oil, 4 much worse than 2. Could it be a blown headgasket? Im a little lost because that still doesnt make much sense to me for all the Sensors having zero affect on how it runs. I mean this thing runs absolutly horrible, idles at -5vaccuum and smoke pours out the exhaust.
If you have any ideas please send them my way, thanks -Sean
SilvrEclipse
01-04-2009, 01:53 AM
Welcome to AF!
Wow this is a strange problem, seems like you have eliminated alot of possible problems already, its hard to believe you have not solve it already.
Have you checked the timing yet? Maybe the belt skipped a tooth and thats why your getting low vac?
Wow this is a strange problem, seems like you have eliminated alot of possible problems already, its hard to believe you have not solve it already.
Have you checked the timing yet? Maybe the belt skipped a tooth and thats why your getting low vac?
Tal92on
01-04-2009, 04:16 AM
Yes, i forgot to mention a couple things such as that. Timing has been cheaked, its dead on. Ive also even a different Cam angle sensor, so thats not it either. Both the bottom end and head are fresh with only a couple hundred miles on them so its hard to believe it may be a bad valve stem seal or something seeing as they were just replaced....Idunno, im lost. Thanks for your help though -Sean
steviek
01-04-2009, 01:18 PM
Yea it is sounding like a head gasket or warped head or possibly if you are very lucky is it possible that your torque specs on your head studs are too low? I mean oil doesn't get in the exhaust manifold from any other source but the engine so when you saw that while checking injectors etc etc is always good and helpful that really wouldn't solve the oil problem which is most likely 99% whats causing the poor performance.
Did you notice any coolant misxed with the oil or was it pure oil?
Did you notice any coolant misxed with the oil or was it pure oil?
SilvrEclipse
01-04-2009, 11:39 PM
He said the compression checked ok though. Maybe the HG is leaking under the pressure from combustion?
steviek
01-04-2009, 11:51 PM
hmm well where else can the oil come from?
Tal92on
01-05-2009, 08:38 PM
The only other theory i have is that something is wrong with the oil ring on the 4th cylinder. That would explain the burnt oil and the high compression. Im sure you know already, but if the oil ring isnt dragging the left over oil in the lower cylinder back down then the engine has no choice but to fire anyways and burn it off. This problem would also trick when doing a compression test by showing excellent compression readings when they really may not be to great. Im still lost, i took my head off and brought it into my local shop, ill have them cheak over everything and make sure its good to go. If not, then i guess i get to dig into the bottom end. Thanks for your help though guys -Sean
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