Hi all,

A few weeks ago I replaced the spark plug tubes on my 2000 c2. Once I figured out how to take the old ones out (long bolt with nuts and washers) it was fairly straight forward. When I got the old ones out it seems as though previously some silicone was used to seal them. So this was a greyish coloured silicone and was around both the o-rings on each of the tubes. I cleaned out what I could of the silicone inside the cam covers and installed the new tubes and seals. I oiled each new o-ring using fresh engine oil and then inserted each one into place and all seemed to go in well.
I checked recently underneath around the areas and can see there is still some leaks appearing from 4 out of the 6 tubes albeit smaller seeping but does collect on the edge of the cam cover.
Have I installed these incorrectly or should I have used some kind of silicone? I followed the instructions in the Bentley manual which said to just use oil to lubricate the o-rings and thats it
I do need to take a closer look and see if its coming from inside of the tube from around the spark plugs or from the larger o-ring
Any guidance appreciated

 

Silicone is not required, the lubricated o-rings should seal by themselves.
But if that is still the case after 25 years?

 

Is there bigger or different Oring?

 

No silicone required, but the old stuff might be stopping the new seals from sealing properly.

 

This is what im worried about as the access is difficult especially further in to where the smaller ring sits

 

a few decent heat cycles and it might seat better

 

As long as you asked.... good possibility below is whats happening. Good place to start anyhow.

"I cleaned out what I could of the silicone" If it were me, I'd try again to completely clean all silicone off spotlessly.

You need to remove ALL the old sealer/silicone to allow the o-rings to seat/seal correctly. O-rings need a totally clean smooth burr free, lubed surface to seal correctly,

 

I hope this is true. Would save me the hassle for sure

 

yes that is the plan but I’m unsure on how to reach the area where the smaller seal sits further in board. Do you have any techniques or a specific tool that would help?

 

I'd probably use a plastic tube of some kind with a vertical slot. Try to create a protruding edge so when you put it in the hole you can spin it and it will cut slightly....use plastic to avoid scraping the aluminium.
Even a bit of pvc drainage type pipe or conduit might do it.

 

I suspect the plastic tubes will always leak. Consider these aluminum ones: https://www.rauchandspiegel.com/prod...rsche-986-996/

 

the plastic tubes are fine, just replace when you do the plugs. Mine have been leak free.
$40 each for alum. or $40 for 6 OEM....one of those items that don't need "upgrading"

 

I guess this is a bad time to ask if the Uro ones work just fine?

I can get them for 1/3 the price of genuine at Pelican. Are these something a local dealer would source cheaper? Last time I quoted a part + o-ring at the dealer they were $7 orings, and each of these needs two…

 

yes i think they work fine, all of them have modern viton o-rings i think so should be good to go

 

No, have no specific technique to remove the spark plug tubes old silicone sealer that shouldn't be there to begin with...
But have removed more than my share of old silicone sealer from engine parts. Its a pia for sure.

Just try and not drop chunks of old sealer into the engine when tube is out. maybe try and make an appropriate tool like SimJen suggested. Or depending on exactly what/how much is still there and where its stuck to will determine what to use. Maybe make a narrow tube type attachment for a shop vac to help suk old silicone/sealer out once you dislodge it to keep it out of the engine.

Probably any of the tubes offered on Pelican parts or FCP or oem Porsche will work fine, most will come with o-rings.

Problem the old oem original tubes had was the plastic got old and brittle fast. Cracks in the tubes caused leaks and they would crack if you looked at them wrong.... Hitting them with a new spark plug/wrench is all it takes for some of the old originals to disintegrate.