viscreal2000

I changed my plugs a few weeks back and found some old/dirty oil in the number 4. Surrounding the base of the plug and some of the wall. I'm not getting any tapping, but thought I would ask if anyone knows what this means.

ultimate lurker

Usually that's just seepage from the valve cover gasket. I haven't taken off the valve cover on the F20C yet, but on older DOHC VTEC engines, there is a ring gasket around the sparkplug hole. Sometimes these can seep a bit. Interesting that it's on the #4 though.

UL

Barry in Wyoming

Visceral2000, I hope, I REALLY HOPE this turns out to be a bum lead, but here goes.

When I heard my engine's tapping, the dealer's mechanic pulled all four plugs and found just what you described: oil on top of the #4 piston and a blackened spark plug from the #4 cylinder.

Honda-Tech-Line told the dealer to use a bore-o-scope to look inside the cylinder to see what the cylinder wall looked like. They did and it looked scored. Then Honda-
Tech-Line authorized a new short block to fix it.

I'm not a mechanic type. I'm more of a computer-hacker type. But I don't see how there can be oil seeping through a ring gasket of a spark plug leading to your problem. It seems to me the oil must be getting there by blowing past the rings.

I'd ask your dealer to confirm your finding and then ask them to fix it. You shouldn't have oil in the combustion chamber.

By the way your car looks TOTALLY AWESOME! Amazing wheels. I noted them in the thread on how tire size affects performance.

Barry in Wyoming...

ultimate lurker

Barry,

On Honda DOHC engines you have a valve cover. Obviously to be able to access the plugs, the valve cover has to have holes in it to get to the plug holes in the head. The valve cover mates to these holes in the head (there's a joke in there somewhere :-) and because there is lots of oil flying around in the valvetrain, you need a seal to prevent oil from getting into the plug holes. On all previous DOHC Hondas, this happens to be a flat o-ring gasket made of rubber, usually about 1/4" thick or so, which fits into a recess on the valve cover.

If oil seeps through this seal, it will migrate down the plug hole and settle around the base of the plug where it gets sticky, dirty, etc. Sooner or later this will happen, although I must admit it shouldn't be happening this early. If the oil on viscreal2000's plugs was not on the tip, but rather up by the insulator and top part of the threads, I would suspect my cause (and that's what it sounded like he was talking about). If it's on the lower part of the threads and on the tip, then yes, he's got issues. But oil from your problem should not migrate up into the sparkplug hole.

UL

Barry in Wyoming

UL, I see what you mean and I think you are right. I know I'm a bit "jumpy" about this engine issue.

I think I misread viseral2000's "and found some old/dirty oil in the number 4. Surrounding the base of the plug and some of the wall. " to mean oil inSIDE the number 4 CYLINDER when that is not at all what he said.

Oil inside the combustion chamber is very different from oil on the part of the spark plug outside of the combustion chamber. Oil on the plug outside of the combustion chamber would not be such a serious sign.

Barry

viscreal2000

HMMMMmmmmmm.....it was like a cliffhanger there for a moment...I DID mean outside the chamber. Interesting anyway that it is # 4 though. I never spill oil, and have changed myself since day 1. Anyway, thanks for your replies and compliment (Barry) (: but I think I will err n the side of caution and have it looked at during my diff change coming up.

Note to Rev- Dif has been replaced six times at my honda dealer (4 cars). I think there's a concern by the techs too and they've voiced this to honda. I will get every detail at my service. I know you are happy with your LSD but perhaps can get a new one anyway? Or backing by these guys?

Well....I wonder where that oil came from. THANKS for your responses guys.!