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Very oily spark plugs

 
Old 04-20-2013, 02:30 AM
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545svk
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Default Very oily spark plugs

Good day, can anyone shed some light on this, please.

I changed the spark plugs on my '87 s4 this morning and all the plugs were soaked in oil. The white bodies were full of oil, the threads were oily and the tips as well. In 3 cases even the spark plug socket was oily when I removed it.

I think the previous plugs was in the car for about 10 yrs.

I have had this 928 for about two - three months and 3000 miles. In this time it has not used oil, does not smoke and does not drip oil in the garage.

There is also no oil around the valve covers.

Thanks
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Old 04-20-2013, 02:36 AM
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Lizard928
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From your description the cam covers are leaking for sure,

I dont see a huge problem other than the fact that these plugs show your engine is running a little lean.....

also use copper plugs, such as Bosch WR7DC+
Ditch the platinum plugs!
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Old 04-20-2013, 03:41 AM
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James Bailey
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Get enough oil and it can short the plug causing major misfire.....at least that is true for a BMW 318 went from 4 to 2 cylinders . Wife said it was running a bit rough and had no power......
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Old 04-20-2013, 03:55 AM
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Leak in the gasket seals to the cylinders on your valve covers. They're hockey puck shaped and one for each cylinder.

Mine had a leak on cylinder 8, and a slight on 6. Not THAT hard to change. The driver side is easier than the passenger side to remove. However, you have the possibility of stripping the valve cover bolts and making the job 10x more difficult if they haven't ever been removed before. You have to replace the valve cover gasket also.

I was lucky on my '86 of not stripping anything. Took me 2 days by myself as I was going slow and cleaning up everything as I go.

Get it fixed. You don't want your plugs and wire ends soaking in oil. It'll ground the plug and cause misfiring that the others mentioned.
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Old 04-20-2013, 04:34 AM
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Thanks for the replies. I got a big fright and saw a complete engine rebuilt! Then I thought "stroker!"

I changed the plugs to NGK BP7ES as suggested somewhere in the forum as an alternative to the Bosch plugs. My local shop had the NGKs but not the Bosch. Gap at 1mm and the improvement is huge.

I had the low speed misfire that made it feel wooly and sound like a Subaru. Now it is crisp.

Again, thanks.
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Old 04-20-2013, 09:38 AM
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I have had leaks into my plug housing from the camshaft tower covers and before I remove any spark plugs I clean the oil out to stop any dirty oil and debris entering the combustion spaces.

I have stopped all the leaks by fitting copper washer under the set bolts that hold the camshaft covers in place.

You are probably aware that the camshaft set bolts bottom out in the cylinder heads and the cup washers under the heads of the set bolts compress the "O" rings of the set bolts, the cord seals of the camshaft covers and the "O" rings seals of the spark plug holes. The logic behind these bottom out set bolts is to not overly compress the seals. The bottoming out of the set bolts is designed to compress the seals sufficiently to stop oil leaks.

In time the seals relax and some oil leaks occur. Porsche supply copper washers to fit above some of the cup washer to give a better seal around the centre of the camshaft cover IIRC, but by fitting a full set of copper washers I was able to apply extra compression to all the seals and stopper all the oil leaks. I turned up my wishers from copper pipe and made them around 1mm thick IIRC. If you have a PET or a Tech Bulletin you will be able to identify the washers and you should be able to buy them from an Official Porsche Centre or have them made up.

In some instances where the seals have hardened it will be difficult to get a return to a full seal, but it is worth a try especially to stop the oil leaking into the spark plug holes.
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Old 04-20-2013, 10:00 AM
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Bertrand Daoust
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Originally Posted by Tails View Post
I have had leaks into my plug housing from the camshaft tower covers and before I remove any spark plugs I clean the oil out to stop any dirty oil and debris entering the combustion spaces.

I have stopped all the leaks by fitting copper washer under the set bolts that hold the camshaft covers in place.

You are probably aware that the camshaft set bolts bottom out in the cylinder heads and the cup washers under the heads of the set bolts compress the "O" rings of the set bolts, the cord seals of the camshaft covers and the "O" rings seals of the spark plug holes. The logic behind these bottom out set bolts is to not overly compress the seals. The bottoming out of the set bolts is designed to compress the seals sufficiently to stop oil leaks.

In time the seals relax and some oil leaks occur. Porsche supply copper washers to fit above some of the cup washer to give a better seal around the centre of the camshaft cover IIRC, but by fitting a full set of copper washers I was able to apply extra compression to all the seals and stopper all the oil leaks. I turned up my wishers from copper pipe and made them around 1mm thick IIRC. If you have a PET or a Tech Bulletin you will be able to identify the washers and you should be able to buy them from an Official Porsche Centre or have them made up.

In some instances where the seals have hardened it will be difficult to get a return to a full seal, but it is worth a try especially to stop the oil leaking into the spark plug holes.
Where does the copper washers go please?
I have this same problem even after changing the spark plug seals on my covers refresh.
Thank you.
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Old 04-20-2013, 10:08 AM
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Fit as per copper washer 32a for every set bolt 33 & 34 so you further compress "O" rings seals 31 & 24 and seal 23.
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Old 04-20-2013, 10:21 AM
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I don't remember but does this mean that I don't have any or I'll put one more there?
Also, I guess that I can install them one by one without any problem. Right?
Thanks a lot.
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Old 04-20-2013, 10:55 AM
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Originally Posted by Bertranddaoust View Post
I don't remember but does this mean that I don't have any or I'll put one more there?
Also, I guess that I can install them one by one without any problem. Right?
Thanks a lot.
Bertrand,

Your '91 probably has the extra spacers already, they were specified for the four bolts along the bottom and the two on the ends (six total, per side). You can see them under the bolt-head if you look carefully. There was a TSB on this, Oct '86-- part of the Jim Morehouse CD set.

Tails is suggesting using them under all 13 bolts per side, not just the six that Porsche specified. That's certainly worth a try if you don't want to do a general refresh. The part# (#32A above) is 900 123 144 30, available from all of the usual suspects.
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Old 04-20-2013, 11:03 AM
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Thanks Jim.
I think I'll try that as I started to get some oil - not mutch - again about two years after my CC refresh.
Many thanks guys.
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Old 04-20-2013, 11:21 AM
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Just checked and I don't have any!!
Hum...
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Old 04-20-2013, 11:42 AM
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Originally Posted by Bertranddaoust View Post
Just checked and I don't have any!!
Hum...
Should be an easy fix, then-- particularly if the rubber seals are only a couple of years old. I think removing one bolt at a time and adding the spacer will work fine.

Cheers, Jim
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Old 04-20-2013, 12:00 PM
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Bertrand Daoust
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Actually, the seals are 3 years old.
Just looked at Dwayne's tutorial on the CC refresh and he mentions that Porsche put some of those washers in the '87, '88 and in some '89 but none on 90+.
Probably I didn't put any as the car didn't have any.
Should be an easy fix like you mention.
Thank you.
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Old 04-20-2013, 01:15 PM
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Originally Posted by 545svk View Post
Thanks for the replies. I got a big fright and saw a complete engine rebuilt! Then I thought "stroker!"

I changed the plugs to NGK BP7ES as suggested somewhere in the forum as an alternative to the Bosch plugs. My local shop had the NGKs but not the Bosch. Gap at 1mm and the improvement is huge.

I had the low speed misfire that made it feel wooly and sound like a Subaru. Now it is crisp.

Again, thanks.
You know that NGK BP7ES are two ranges colder than stock, right?

Dan
'91 928GT S/C 475hp/460lb.ft
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