Dharn55

Oh Boy, another major problem! Replaced the pulse sender today and got the engine back in the car. The good news is the engine started right up. The bad news is within 15 seconds or so I had a major oil leak. The green cam plug for the intake cam on the 1-3 head that was fixed had popped out. I was not too surprised at this because in reassembling the engine I had noticed a problem. When I went to put in the cam plugs I found that the hole for this cam plug was distorted. In looking closely at the head I saw that it appeared to have been dropped and slightly bent at this location. I then looked at the FedEx Ground box and saw the damaged to the box that I had not noticed. As an aside the shipment was insured for $500, but I don’t know if or how to collect from FedEX. In any case, it was very hard to get tis plug in as the head was bent in slightly at this location. It had not affected the cam journal so I decided to go ahead in install the plug and see if it leaked. If it did I assumed that I could dremel the hole round or have it machined.

Initially I thought that it was jut this plug coming loose. But when I looked at the puddle of oil I found the small metal cap that is in the picture next to the green plug. This is obviously one of the plug used to seal off oil and water passages in the head. It had come out with the oil. However, at the location of the cam plug/cam journal there is now way a metal plug from elsewhere in the head could get out at this spot

So I talked to John Edwards at Costa Mesa R&D and he had a cam there and confirmed that the cams have plugs in both ends. The plugs a about .590” or 15mm. he said that you can buy them at a NAPA store and reinsert one with a wood or metal drift. He did not think I would have to take it to a machine shop, but could do it jut by putting the engine of the ground to have good access to the end of the head. It had to be the oil pressure when this cap cam out that forced out the cam plug. I only expected I might have a slight leak, not oil pouring out of the engine. I am thinking that the plug could have been damaged by the cam holding tool that I fabricated as it allowed the bolt that went into the end of the cam to push against the plug.

Any one have any experience with this?

I am going to take a break for a few days, as I have been spending a huge amount of time on this in the afternoons and evening, and we are going out of town tomorrow for a wedding ( I had hoped to drive the car to the wedding, but that isn’t going to happen). Next week I guess I will drop the engine again ( with the practice I have had in the last two drops I have it down to about 3-4 hours) and try to put in a new plug. May not be as major a problem as I first thought, but what a hassle!! (or an adventure).

ivangene

Dude - sorry

deckman

Snake bit. You are fortunate you have the skills to do all this yourself at least. For most it would be a never ending hole in the bank account. Not that it isn't for you, but you're saving a few bucks doing it yourself.

Jake Raby

Been there done that... Mode of failure #11. I first saw this 5 years ago!
This is the reason why I drill and tap the cams in all my engines for thread in style plugs.

Every instance that I have seen where the plugs were dislodged and just tapped back into place resulted in another dislocation...

I have seen engines totally fail due to this when they dislodge the plug, blow off the green cap and puke all the oil out... The dealership that had the car this occurred to called me to ask me what happened and they didn't know the cams had plugs in each end!! Lost... Totally lost.

Not a new failure for sure... Been there, done that and created a remedy for it.

washington dc porsche

I think I'm more upset than you. :\

Dharn55

Jake - Thanks for your response. Do you have a source for thread style plugs or is this a proprietary product? I also heard from a member of another site that he had his welded in. What do you think?

There are several of these caps in the heads, and I assume others in the engine. Do you drill and tap all of them in your engine rebuilds?

I really don't want take the head off again, or totally disassemble the engine, but it might make sense to take off the cams on this one head. The machime shop were the head was repaired (they had nothing to do with the cams as the cams were never sent to them) seemed to think that installing a new plug (said not to try to reuse the old plug) would do the trick, that these plugs are in lots of engines. This is a new "mode of failure" that I have never heard of before.

Jake Raby

I would not trust reusing the old plug.. It has already been compressed and has lost it's "crush".. To me that would be a liability.
(but thats just me)
I do replace every one of these that I can possibly drill and tap and find the correct threaded plug for.. Those that we can't "Overkill Engineer" with this method are set in place with Devcon...

The cams can be removed to facilitate this repair without pulling the engine or the head.. It is not an easy task in a 996, but it is possible.