Oil in cylinder #2

[Eli W]

So, a new purchase hotrod has oil pooling in cylinder #2 and has the expected detonation problems with oil fouling.

I did a PPI and this came up on inspection but everything else looked good and the shop doing the inspection said a tune may fix the problem well a tune did not fix it.

I do not have a good history on the motor which is really what I need but what I do know I will share. The motor is a twin plug 3.0 with 3.2 heads running electromotive crank fire, over 3,000 rmps the engine comes alive.

I know oil is only in one cylinder and the cylinder has no scoring.

It gets spark.
the injector is working properly
compression is good
leak down is good
There is no oil leaking around the cylinder or under the car, oil is getting pushed into the exhaust port

The history on this car is poor in that I do not have a lot of information, but the evidence so far points to a car that over all is in good shape except for this one significant problem.

Here is what I'm thinking, the car could have been sitting for a long period of time and the oil leaked down into that one cylinder. The rebuild on the motor looks fairly new and from all appearances it looks like it was done well.

Before I drop the motor and crack it open I need to drive the car for a few hundred miles and see if the oil in the cylinder does not resolve itself. The oil rings could just need to seat a little more.

What do you think?

[cgarr]

Are you able to look down the intake for oil? I would drive it then check things out. Otherwise if they used Teflon seals on the heads those can come loose sometimes

[Eli W]

What would looking down the intake for oil tell me? Not being smart I just have never run into this before.

They found the leak after removing the spark plugs.

[cgarr]

You might have oil pooling in the intake from the case vent and getting in #2 cylinder? It would just eliminate the intake as the problem.

[KTL]

If the oil level in the external oil tank is a bit too full, the engine crankcase pressure can force the oil tank to push/puke oil into the intake.

So what Craig is saying is, eliminate the oil tank as a potential source of that oil in the cylinder. Make sure the oil level on the dipstick is 1/2 way between the two marks when the engine is at operating temp/fully warmed up.

[Eli W]

I will check that out as well.

I want to eliminate anything outside the rings at this point before diving into the motor.

Thanks for the suggestions.

[Walt Fricke]

Bad rings in one cylinder should show up on a leakdown test. Especially the sound you hear listening in the engine oil breather tube. You don't need a stethoscope - a piece of tubing you can stick in your ear will work fine.

[matt demaria]

Bad oil control rings do not show up in either compression or leakdown.

[Walt Fricke]

Not entirely clear what the circumstances are here. For instance, if the engine sat a long time, was that when this excess oil appeared? If you sort of clean it out (suction through plug hole, jacking car up on one side, blowing air through with exhaust valve open and intake closed, something), do you get a period of more or less clean running? How quickly does the pooling come back?

Overfilling the tank doesn't particularly connect with a problem only in #2, does it? And I am guessing you aren't running CIS? With carbs or EFI you don't usually connect the breather system with the intake. If you were to connect it to the air filter, that typically would be on the right bank, but usually a separate breather, with an air filter, is used - engine vents to oil tank, oil tank to breather instead of back into the engine air intake system.

Some of us like to delete the valve stem seals on the exhaust. Little or no "suction" present there to help oil from the valve cover area flow uphill, and what does shouldn't get past the port into the combustion chamber when the engine is running. If the case filled with oil up to the level of the cylinder bottoms, and a valve were open, maybe capillary action (and maybe rings whose gaps lined up just wrong) might explain it?

Run and clean plug, run and clean sounds like a decent approach.

[Eli W]

The car is running CIS.

I do not have a lot of history and info to go on currently. The car is in Cali and I'm in Oklahoma, it is going to be shipped to me soon I hope.

It is at Truspeed out there and they are the ones who have looked at it. The car very well could have been sitting for a long while. The story I have is that a Nephew got the car from his uncle who rebuilt the motor and then sold the car. Electromotive seems to be working fine, and the one major issue is the oil in cylinder 2.

[Walt Fricke]

The electromotive crankfire is bulletproof.

Like many before and after me, I once added oil on a Saturday morning at a race track to my 2.7 with CIS because the dip stick showed low. Just a quart. Made a fair bunch of smoke on the track after I sloshed it around on the track. So that could have an effect. But I suspect that smoke and a general mess is the result, not raw oil pooled in one of six cylinders. On the 2.7 (and I think the early 3.0 like yours) the path is from the oil tank to a fitting on the right side of the air filter housing, below the filter. That way the engine and tank can breath, if needed, filtered air, so dust and stuff can't get drawn in.

As a result, if overfilled oil can slosh up into the filler neck, through the hose, and into the air box in that area. Leaves it very obviously oily. The air box has a drain, which ends up part way down by the engine oil cooler. Overfilling can lead to oil coming out this drain, and causing consternation there as well, and can be hard to differentiate from oil coming from bad seals on the idiot light switch or the oil thermostat.

Once oil gets sucked through the air metering plate, and over the crossover rubber piece, and into the airbox proper, it is now in a common plenum, from which all six cylinders draw with separate runners. Especially on the early CIS motors, with no extra stuff to deal with the cold start valve and exploding airbox issues, there isn't anything in particular to divert this oil preferentially to one cylinder or another.

Still, overfilling could have the effect of raising the case sump oil level, and that could lead, under the wrong circumstances, to oil getting where you don't want it.

Good luck with it.

[Eli W]

I will keep everyone informed about the car , it apparently has a bad alternator I will have to tackle that as soon as I get the car in my garage.

The compression is good the leak down is good the af is good, I going to drive it and check it out after a few hundred miles.