burning oil/misfire cyl 1

rockyracoon · Nov 27, 2009

I can smell oil burning coming from the tailpipes.the number one plug is wet with oil but not sludged or coked.I am getting a CEL for cyl 1 misfire.the weird thing is that a leakdown test did not demonstrate excessive leakage and virtually none out the dipstick tube,a little out of the throttle body and some out of the exhaust pipes.I was thinking rings because it seems to be burning all of the time,but im not positive of that since this car is new to me and I have only had the car idling in the driveway.car has excess of 169k on clock.I did notice the PCV hose had a crack in it,but im not sure if it is leaking vacuum.

wmburns · Nov 27, 2009

What are the compression values and the leak down percent?

But if the leak down tests shows the sealed intake/exhaust valves and rings to be acceptable but there is oil on the spark plug doesn't this leave valve guide seals? The oil is coming into the cylinder with the Air/Fuel charge (via the intake valve).

Also, oil would be added to the exhaust gas output contributing to the oil smell in the exhaust.

IMO, the oil is not burnt/coked because of the extream misfire is not allowing the cylinder to get hot enough.

I am wondering if the intake manifold was pulled if the oil could be seen on the intake valve to confirm the diagnosis.

rockyracoon · Nov 28, 2009

well the compression in that cylinder is 150PSI matter of fact so far that whole bank of cylinders is 150 psi,the leakdown on number1 shows 40%
the rest on that bank are around 30-35%,number one seems to leaking a little more than the rest and the air seems to be coming out of the crankcase because you can hear it coming from the V/C where the pcv valve goes.

the other thing I have just noticed is number one plug tower on the coil pack is barely firing,so that may explain why the sparkl plug for that cyl is fouled looking.

wmburns · Nov 28, 2009

Are you smelling oil in the exhaust or GAS?

I may be all wet but the leak down numbers don't seam so far out of "aceptable".

It does seams far fetched to think that valve guide seals give out on a single cylinder and are OK on the other cylinders.

burning oil/misfire cyl 1

rockyracoon

wmburns

rockyracoon

wmburns

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