[BigL2U]

Since my car has 62000 miles on it I decide to change out the original spark plugs, cap, rotor, and wires.



When I pulled the boot off of the spark plug in cylinder two I noticed some oil at the base of the plug. When I removed that plug it was not even hand tight. <img src="/forum/images/smilies/968/dry.gif" class="smilie" alt="" />



The other plugs look okay and none of them seemed abnormally fouled. I'm trying not to read a ring job into this but I was wondering what you all think I should do next.



Oddly enough, the cap and rotor seemed to be the most worn. The lead on the rotor was almost completely gone compared to the new one.



I thought the car has been running pretty strong. I can't wait to see what it'll be like with all four cylinders working. <img src="/forum/images/smilies/968/blink.gif" class="smilie" alt="" />



Any advice would be greatly appreciated.

Partial Post: Please Login or Register to read the full post.

[bob blackwell]

Oil gets into the spark plug access tubes due to a failed o ring at the bottom. There is usually no problem due to this except a messy plug change until you replace the o ring. This will require removal of the valve cover and I recommend you replace all four of them and check out the vario cam tensioner, chain, rubbing pads and camshaft sprocket teeth at the same time. I also found some of my plugs loose when I first changed them but have taken to inspecting them more often now and it has not happened again. No telling how long those first plugs had been in use and vibrated loose over time. If you are really concerned about the condition of the piston rings, have a compression check done and a leak down test if it is indicated. This will reassure you of their condition. Our engine (and 944 engines too) seem to last a long time before needing new rings. Good luck, Bob Blackwell.

Partial Post: Please Login or Register to read the full post.

[BigL2U]

Thanks Bob, I'm sure you heard my sigh of relieve.. <img src="/forum/images/smilies/968/cool.gif" class="smilie" alt="" />



According to service records the car had a Variocam service at 48K miles. So I was going try and wait until ~70K miles before I did another inspection. But as you suggested, I'll keep my eye on it for now.



I also measured the resistance of the old plug wires vs the new ones. All of the new wires read ~ 4K ohms. One of the old wires read 3.1K and the other three were 4.4K.



Wierd, but I suppose that's within spec.



Thanks again!

Partial Post: Please Login or Register to read the full post.

[gbarrier]

Sounds like just a loose spark plug. We bought our 968 several months ago from a used car dealer. My son and I drove it pretty hard before we bought it and it ran fine. Of course we didn't know the condition of the cam sprockets but that's another story. We signed the papers, paid the man and headed to the car to drive it a couple of hundred miles home. My son started it up and turned on the A/c while we walked around it one more time. Then we hopped in, started out of the lot and there was a dead miss on one of the cylinders. We drove it briskly down the street and back to no avail. I was devastated. We borrowed a plug wrench and pulled the plugs. As I pulled the #2 plug out, there was oil all over the plug as well now my plug wrench. I just knew that we had big problems. After letting the oil drip off the plug and putting it back in, The engine ran fine. During that time quite a p.....g contest had gone on with the seller who still had my money in his back pocket and would not let me out of the deal. I wiped out the oil, tightened the plug and started home. The car never missed again. 200 miles later the plug was clean and there was no more oil and there has not been for several thousand miles now. I did notice that the plug just unscrewed when I took it out and when I put it back I could feel the washer crush like a new plug when I tightened. With any luck you probably have the same problem. These plugs had some age on them too. We had just driven it hard enough to make the cylinder pump oil as compression escaped by the loose plug.



Good luck

Partial Post: Please Login or Register to read the full post.

[MLB]

Just changed out the plugs tonight, with Bosch 7990s. Starting from the front I was concerned to see a small crescent of oil around the top of the plug. And it was really tight. But the next two plugs had a LOT of oil pooled around them, and only one felt loose to remove. Back plug had only a little oil. Job turned into a six-shop-rag clean-up party. But runs fine now with the new plugs. I have 17 years of maintenance records from POs, but no indication the plugs had ever been changed on this 94 cab. The old plugs were triple prong Bosch. Anyone know if those could have been original to the car?

Partial Post: Please Login or Register to read the full post.

[bombfactory]

You might need new seals around the plug holes. I also had some oil pooling in the spark plug wells so I changed them out when I had the valve cover gasket replaced.

Partial Post: Please Login or Register to read the full post.

[DaveN]

+1 on the plug seals.

Partial Post: Please Login or Register to read the full post.