Possible fuel in oil

[TX82FIAT]

I'm interested in opinions on how to approach possible wash over rings or blow by issue. It could be a valve issue, timing issue or even a fuel mixture. Car is running fine. no noticable pre or post detenation with a slight oil leak that has been there for some time that i think one of the guy croft thick head gaskets will fix while lowering the compression ratio a little. After a track day I noticed the oil with about 1000 miles on it was very black and thin with a faint smell of gas. I use redline oil and therefore the change in consitency of the oil was apparent. I changed the oil and have run it another couple hundred miles and have noticed the oil looks prematurely black and thin from a dipstick test. could not pick up on the smell of gas but the consitency of the oil wqas off again.

So, I'm interested in opinions on all things to check. Timing, valves propper open and shut, look for deposits in cyclinder, leak down test, adjust fuel injection system for proper mixture. If I have washed over the rings, How will i be able to tell if new rings are needed once the problem that may have lead to this condition is identified. I've heard of people sending a sample of engine oil off to a lab for a nominal fee to have the lab diagnose the oil..... not sure that will provide any additional insight.

Thoughts, ideas. I'm going to drive the car up to Vic Autosports in Dallas next week since i think this may be over my head and i have a lot of confidence in Andy.

[So Cal Mark]

pretty much have to do a leakdown test to evaluate the rings. Hard to believe your programmable FI system is that rich without noticing it

[TX82FIAT]

Mark, i agree.. if it is running so rich it washed out the rings there should be more than a little smoke coming from the tail pipe when giving it some gas. The serial port i have hooked up to the system has not been able to connect to the laptop for me to evaluate the mix. Just don't want to ruin what I know is an outstanding motor. Who knows, maybe I ran it hard with too much oil in the engine but don't think so. A leak down test will do the trick.

[vandor]

> Who knows, maybe I ran it hard with too much oil in the engine but don't think so.

I normally run half to a quart over the full mark, to avoid oil starvation during cornering. You would have had to have it way over full to do any damage.

> A leak down test will do the trick.

The leak down test will give you an idea on the condition of the compression rings, not the oil control rings. Since they are made of different materials they may not be affected the same way from an over-rich mixture. I asked about this when I talked to the tech departments at Total Seal piston rings, and they said it is definitively possible to have bad oil rings and get good leak-down numbers.

[TX82FIAT]

Csaba, well that makes more sense. I'm pretty sure there is not a lack of power from a lack of compression. Also, there is no heat build up so I'm pretty sure the heat is transfering from the compression rings to the cylinder walls for proper cooling. The engine only has about 1400 miles on it. Do you think this could be related to the rings not seating? I have not looked at the repair manual yet but I'm confident removing the head is all that is required to gain access to the pistons. That needs to do that anyway to fix the oil leak anyway.

If I had to guess there is excess fuel at a high RPM range (above 5000) and that is why I have not noticed. I'll keep it to under 4000 RPM's on the trip to Dallas next week.

Should i do anything like put a couple teaspoons of oil down the spark plug hole to recoat the rings before the drive to Dallas. Seams like a waste of time since the head is coming off next week and i changed the oil a couple hundred miles ago. let me know if you have any other insight. I would have never thought about the difference in materials between compression rings and oild rings.... Hello! Thats why they call the lower ring the oil ring!

Thanks, Ray

[vandor]

Hi Ray,

> Do you think this could be related to the rings not seating?

It's usually the compression rings that don't seat, often because the bores were not honed properly. Not sure if the oil control rings ever not seat properly.

> I have not looked at the repair manual yet but I'm confident removing the head is all that is required to gain access to the >pistons.

Well, you can see the pistons if you remove the head, but to get to the rings you have to remove the pistons.
It can be done without removing the engine, but it takes some work.

>Should i do anything like put a couple teaspoons of oil down the spark plug hole to recoat the rings before the drive to >Dallas.

No need. The cylinder walls get oiled every time the piston goes up, and then the rings (the oil ring first) have to pass over that. I would change the oil, in case it is diluted with gas.

If you have time come by the shop, or we could grab lunch.