I have a 2002 R50. One morning last week the oil light came on, so I went poking around under the hood. I noticed oil on the valve cover all around wire #2. When I pulled the wire out there was, what I expected to see, oil in the spark plug well. A few days later I changed all 4 spark plug tube seals, started it up and...........the SAME problem(same cylinder)! What?! So, I thought maybe, just maybe I got a bad seal and I replaced it with another new one. STILL the SAME problem! Anyone have any ideas about what the hell is going on?

 

Look for cracks in the plastic cover.

 

I did inspect it pretty thoroughly and I didn't see anything.

 

There are not many alternatives. The metal spark plug tubes are usually very tightly pressed into the head. Should be no wiggle.

Some cams can interfere a little bit with the tubes, so someone might have modified them. Just something to look for.

 

I just replaced the head with a reman about 3000 miles ago and the cam looked fine as far as I could tell. I know that what you're telling me is right about a crack being a possible cause, but I just didn't see anything. Man, this is killing me.

 

Not that this is what your issue is, but found this info that may be useful (cannot link thread as it's blocked from NAM):

 

You just gave me a migraine, PelicanParts

 

Is this happening with OEM MINI gaskets or aftermarket.

 

Both OEM and aftermarket and just cylinder 2

 

I don't know for sure if the spark plug tube is the problem, but if it is, is it as simple as pulling the old one off and sticking a new one in?

 

They are pressed in and should be hard to remove. If you can wiggle it or pull it out with your hands, you have your answer.

 

Valve cover gasket?

 

Well, I'm probably going to dig in this evening and get a closer look at the tube. As far as I can tell, at this point, the tube just pulls out and the new one can be reinserted and tapped in with a block of wood and hammer.

 

Might not be a gasket/seal issue. It might be the plug itself.
Have you tried swapping the plugs to see if this condition follows the plug currently in cylinder #2?

 

No, sir, I have not, but you can bet your butt I'm going to try that out in a couple hours! Thanks for the suggestion

 

You see what's going on here, right? So, could this friggin insert be causing my problem?

 

Sure. If it's that loose that it comes off with the plug than it couldn't be well sealed.
Think you are on the right track.

Surprised that a rebuilt head had an insert. They usually will not accept them for rebuilding. An appropriate oil resistant thread sealant may be all you need. I have had great tech support when I have contacted loctite directly on a question like this.

 

Bingo!

Yup... I'd be on the horn pretty quick with whomever supplied/installed the re-manufactured head to inquire about this...

 

About 60 seconds after understanding this situation, I called the shop where the head came from. However, because of a time difference, they're currently closed and I'm going to have to stew in my anger for another hour or two. Soooooooooooo, I'm going to give loctite a shot for now and see what happens.

 

The shop told me that time-serts are commonly used when rebuilding heads. I, personally, have no idea if this is true or not. The shop manager said that they rebuild heads for high end cars on a regular basis and use time-certs, when necessary, in all of them. Anyway, he agreed to pay for the repairs at a garage of my choice.

 

The spark plug tubes are pressed in with Loctite. If it is loose or wiggles with hand pressure, then there is no way it is sealing and will fill with oil from the bottom. Meaning oil will wick into the spark plug tube from the rocker area (where oil would normally flow to migrate to the drainback areas). The spark plug thread insert would have nothing to do with this except that the remanufacturer probably pulled out the tube to install the insert and pressed the tube back in without Loctite.


I should be able to get my hands on the original engine build book used by the Chrysler prototype build motor room that has the correct specifications for Loctite and tube installation procedure this Thursday. I can't remember right now if we used the green or red Loctite.

 

Yea, I've been wondering how a loose insert would cause oil in the tube. I'm not a mechanic, but that doesn't make much sense to me.

 

Yea, they are in there pretty tight with loctite, should not move. Thanks for the additional info UL.

For example

https://www.ecstuning.com/Search/SiteSearch/11127508536/











Believe it was red , you can see a little residue.

 

If you are going to do any of this yourself, call/email loctite or check out their newer "oil resistant" variants. They have updated many of the classic products with versions intended for extended contact with oil.

 

I called loctite yesterday and they confirmed that the thread locker would provide a gasket type barrier against oil and chemicals. Can anyone confirm that the spark plug tubes can be pulled out and tapped back in?