Head gasket/seal problem? - 986 Forum - The Community for Porsche Boxster & Cayman Owners

kiosko · 03-11-2019, 08:24 AM

Guys I got a cylinder #1 misfire and when inspecting the coils and spark plugs, I have found a pretty nasty oil leak on the heads around cylinder #1. When i took the coil out of cylinder 1 and 2, both had oil puddled in the bottom of the spark plug chamber. The top of cylinder one was pretty dark and visible deposits. Does this mean it has been burning oil for a while? The amount of old oil around that area of the head leads me to suspect that. Is this a blown seal or a head gasket issue? No water mixed with the oil anywhere. Can you do a head job with the engine still in the car? The car is a 3.4 early tech art mod done by an independent dealer and has benn driven only 3k in 10 years+.

Paul · 03-11-2019, 02:36 PM

Assuming you still have a 2000 S, start by replacing the spark plug tubes and O rings.

Paul · 03-11-2019, 02:42 PM

https://www.pelicanparts.com/catalog/SuperCat/1048/POR_1048_ELIGNT_pg1.htm#item1

Geof3 · 03-11-2019, 09:24 PM

I’d bet 9x out ten leaks on the exterior of the cam covers are spark plug tube related. Clean them really well and replace the tubes, plugs and o-rings. Monitor. Prob good to go. Might want to do coils while you are there. There are a variety of things that can leak on top of the engine as well so it could be several things. The oil pressure sensor sits right above there and could be leaking. Most likely if there is oil in the tubes, the inner o- ring has failed, or the tubes have cracked. Porsche motors don’t particularly like sitting. Get the leak figured out and drive that thing to get some blood flowing.

Starter986 · 03-12-2019, 07:36 AM

Would someone mind explaining why are the spark plug tubes necessary?

The tube o-rings are keeping oil from where? Why are there not tubes on other automobiles, particularly domestics?

Do the tubes serve only to seat the coils?

Thank you.

PaulE · 03-12-2019, 12:41 PM

Quote:

Originally Posted by Starter986

Would someone mind explaining why are the spark plug tubes necessary?

The tube o-rings are keeping oil from where? Why are there not tubes on other automobiles, particularly domestics?

Do the tubes serve only to seat the coils?

Thank you.

I think they isolate the spark plugs from the oil in the top of the cylinder head. The spark plugs go through the cam covers to get screwed into the combustion chamber in the top of the head. The spark plug tubes were eliminated starting with the 3 chain engines in 2002 on the 9996 and 2003 on the Boxster.

Starter986 · 03-12-2019, 12:44 PM

Quote:

Originally Posted by PaulE

I think they isolate the spark plugs from the oil in the top of the cylinder head. The spark plugs go through the cam covers to get screwed into the combustion chamber in the top of the head. The spark plug tubes were eliminated starting with the 3 chain engines in 2002 on the 9996 and 2003 on the Boxster.

Gotcha. Thank you.

kiosko · 03-12-2019, 02:35 PM

Thank you guys for the quick reply. I will definitely replace all the tubes and orings as soon as i can figure out the misfire. Trying not to put anymore money in the car if the engine is dead. If a new coil in cylinder #1 makes it run smooth again, I’ll do all the coils, tubes and spark plugs. My concern is that the head gasket leak around cylinder one is something internal with seals, orings, valve seats, or the gasket itself which sounds like you have to pull out the engine to do. Lots of $’s i don’t have!

Paul · 03-12-2019, 04:50 PM

The cause of the misfire might be the oil in the spark plug tube.

Gilles · 03-12-2019, 06:34 PM

Quote:

Originally Posted by kiosko

Thank you guys for the quick reply. I will definitely replace all the tubes and orings as soon as i can figure out the misfire. Trying not to put anymore money in the car if the engine is dead. If a new coil in cylinder #1 makes it run smooth again, I’ll do all the coils, tubes and spark plugs. My concern is that the head gasket leak around cylinder one is something internal with seals, orings, valve seats, or the gasket itself which sounds like you have to pull out the engine to do. Lots of $’s i don’t have!

Kiosko,

Yes, before you have brain surgery, try an aspirin..

Seriously if you replace the ignition components (plugs / coils) your engine should run much smoother, the plastic tubes and o-rings should take care of the oil leaks, and the timing is perfect to do them at the same time.

Afterwards, wash your engine and would be able to spot any other oil leaks (if any..)

Good luck

Geof3 · 03-12-2019, 10:56 PM

Quote:

Originally Posted by kiosko

Thank you guys for the quick reply. I will definitely replace all the tubes and orings as soon as i can figure out the misfire. Trying not to put anymore money in the car if the engine is dead. If a new coil in cylinder #1 makes it run smooth again, I’ll do all the coils, tubes and spark plugs. My concern is that the head gasket leak around cylinder one is something internal with seals, orings, valve seats, or the gasket itself which sounds like you have to pull out the engine to do. Lots of $’s i don’t have!

I think you are confusing the cam covers for heads. If there is a head issue, usually that translates as an intermix issue (milky coolant). Pictures would help, but I would bet it’s the tubes, and if not, cam cover needs to be resealed.

kiosko · 03-13-2019, 04:05 AM

Thank you guys much appreciated. I will put in one new coil i bought over the weekend and see if it runs smooth again. if it does i will ordered 5 more coils and tubes to go with the new spark plugs.

Paul · 03-13-2019, 05:31 AM

If the tube is leaking, the oil will seep into the spark plug terminal of the new coil and may cause misfires. Highly recommend replacing the <$10 tube and seals first.

kiosko · 04-06-2019, 08:45 AM

Quote:

Originally Posted by Gilles

Kiosko,

Yes, before you have brain surgery, try an aspirin..

Seriously if you replace the ignition components (plugs / coils) your engine should run much smoother, the plastic tubes and o-rings should take care of the oil leaks, and the timing is perfect to do them at the same time.

Afterwards, wash your engine and would be able to spot any other oil leaks (if any..)

Good luck

Finally got back to the car today. figure out #1 is the completely opposite of 6 where the oil leak is at (no oil on one). After feeling like an idiot, i swapped the coil in 1, nothing changes, engine runs super rough (feels like it only running on 5 cyl) raw fuel smell out of exhaust. did a compression test and make shift leak down test with weird results. a mechanic friend and i were stomped. 0 compression but pushing air into it, does not leak. see new thread today, i’ll try to link. Any ideas, i’m stumped.

Weird compression test results 2000 986 S

Gelbster · 04-18-2019, 06:27 PM

Although it is extremely rare for the head gasket to fail on an M96,a cracked head is much more likely. But that would pressurize the coolant(measure it) or contaminate it with oil or combustion gases(measurable)

BYprodriver · 04-19-2019, 07:12 AM

Quote:

Originally Posted by Gelbster

Although it is extremely rare for the head gasket to fail on an M96,a cracked head is much more likely. But that would pressurize the coolant(measure it) or contaminate it with oil or combustion gases(measurable)

2000 & 2001 are the most likely to crack too.

Gelbster · 05-01-2019, 07:05 PM

If #1 head has cracked , suggest you start Search for "Intermix". But let's hope it is something simpler.
Whatever the cause of the overheating(like plugged up air intakes to the radiators) you will need to refil with coolant.That really requires vacuum filling. You can try the 'burp' valve method but that may be ineffective.