Need Valve Guides???

[nene]

I need some input of the visual of the following valv/valve guides. I realize this is only a visual...............but a quick story of the car: I purchased it in July 2013 and the PO told me that his PO (Porsche mechanic) had overhauled the engine to some extent, but no paper trail to back it up (BTW, the car has 191k). The engine looks is very clean bottom and top. When I pulled the intake manifold to replace the fuel lines, I took a peak at the intake valves and notice that, in particular one valve was leaking oil, which appeared from the guide Now, the others also have some residue, but I believe the oil is from the over-filling the tank. The valves and guides do not appear as part of a 199k mile engine, but I could be wrong.

Calling all Pros: What are your professional opinions on this?

[pors1968]

ON your third pic it look something drop beside the valve.

[E Sully]

It looks like the valves and guides have been redone. The oil could be from over filling. I would make sure the oil level is correct and then drive the car. After it is up to temperature, check to see if it smokes on acceleration or deceleration, giving you an idea if the guides are ok. Do a compression and or leak down test. This will help see if the rings and valves are seating well.

[nene]

Thanx Sully, I keep the tank at mid level, so I don't think it's that. The compression was about 170 all around, but have not done a lead down. I occasionally get the morning cold start puff of smoke, but none on decel and accel, so that's good. Note, the PO had it for 10 years and only put 8k miles on it, so the car sat in storage for a while. Anything I can add to maybe loosen up the rings if they are stuck?

[Jcslocum]

Just drive it and monitor oil consumption for now. The guides look new so maybe just a bad stem seal.

[earossi]

Originally Posted by nene

Thanx Sully, I keep the tank at mid level, so I don't think it's that. The compression was about 170 all around, but have not done a lead down. I occasionally get the morning cold start puff of smoke, but none on decel and accel, so that's good. Note, the PO had it for 10 years and only put 8k miles on it, so the car sat in storage for a while. Anything I can add to maybe loosen up the rings if they are stuck?

There is some consensus that squirting Marvel Mystery Oil into each spark plug hole and then allowing the oil to set for several days will free up rings. Ideally, you should have the motor on the stand so that the P&C's are vertical and then roll the motor over to TDC for one of the pistons Then flood the single piston with MMO and allow it so sit for several days. Then roll the motor over until the next piston reaches TDC and repeat the MMO exercise. Do the arithmetic and it will take you several weeks to treat each piston and its rings to the MMO treatment.

[nene]

Is it an easy task to remove/replace Valve Seals? Input would be greatly appreciated.

Serge

[cgarr]

Originally Posted by nene

Is it an easy task to remove/replace Valve Seals? Input would be greatly appreciated.

Serge

If you can verify the guides are in spec you could replace the seals in the car but I would not want to do it, you either need to hold the valve closed with air pressure or a coil of rope in the cylinder and compress the spring, problem not much room to work. If the guides are shot no reason to put seals in it just to save some oil, you will just beat the hell out of the seats which will make rebuilding more expensive.

So to answer your question, no

[911 tweaks]

^^^^^^ what cgarr says...listen to someone who knows what he is talking about...jmho...

[Lapkritis]

That much oil from a guide at rest isn't possible. I would be more inclined to place my guess on oil leaking primarily past the piston rings when the engine has rested for awhile.

[nene]

Anyone else have an opinion on this?

Serge

[Lapkritis]

My apologies- not sure what I was thinking when I posted it might be due to oil past the rings. That would also be nearly impossible due to gravity. I'm also in the stem seal boat for my guess. Perhaps the spring on the seal broke for that valve. It does happen although rare.

[john walker's workshop]

intake guides are way up out of the oil that collects at the bottom of the cam tower, so i doubt that much would come down the guide, even without a stem seal.

[Oldporsche]

The seal could be replaced without removing the head.

The oil could be there from just sitting too long. Probably you need to drive it more.

[Oldporsche]

As clean as the intakes look, it has probably had the claimed work done. The discoloration of the interior (brown stain) could come from dye in the gas.

[earossi]

I've been following this thread for a while, since your picture of the puddle of oil on top of an inlet valve was intriguing. Since no plausible resolution has been offered up, here is my "non-professional" opinion.

First off, the oil had to appear AFTER an engine shutdown since that area is continuously washed down with an air/fuel mixture which should cleanse the area of any oil accumulation.

Second, the oil that is present appears to be extremely clean with no discoloration. So, unless you had just changed your oil prior to removing your induction system, I question that what you are seeing is engine oil from your system.

So, is there the possibility that you used some sort of petroleum solvent in the process of dismantling the induction system on the car? Is there a possibility that you somehow spilled some into that single port?

Incidentally, the back side of the valves look pretty clean, and not what you might expect to see out of an engine with more than 100k miles on it. In the 911's I have owned, the valve guides were usually shot by about 80k miles. So my guess is that your car has had at least one if not more upper end refreshes and it appears that you may have had a refresh not to long ago.

[nene]

Earossi,

The oil that you see does not have many miles on it, and that is why it looks clean. Prior to taking the intake off, I did not use any solvents at all. Here is a shot of the Plenum when it was off, Nasty!

The PO did state that the engine had been rebuilt (but no paperwork to prove it), and according to my calculations that I came up with, the engine appears to have approximately 10k miles on it.

all

Appreciate the feedback from all of you!

Serge

[earossi]

Originally Posted by nene

Earossi,

The oil that you see does not have many miles on it, and that is why it looks clean. Prior to taking the intake off, I did not use any solvents at all. Here is a shot of the Plenum when it was off, Nasty!

The PO did state that the engine had been rebuilt (but no paperwork to prove it), and according to my calculations that I came up with, the engine appears to have approximately 10k miles on it.

all

Appreciate the feedback from all of you!

Serge

Actually, that induction system looks pretty good. And, confirms to me that the system has been apart and cleaned at least once in its life! Keep in mind that evaporative emissions system on these cars results in all kinds of dirty residue building up in the inlet plenums. The fact that you can see the base material of the plenum through the oil is pretty good, IMHO.

[Walt Fricke]

I couldn't find where you told us what engine this is? However, the last picture makes it look like a 3.2 intake?

Judging from the oil in that picture, I'd guess that is the source of a bit of oil in the intake port area. Why not just clean out those parts of the intake, plus whatever else you can get at conveniently between the air filter and the intake manifolds, wipe out the ports with a rag or towel, and call it good for the moment.

I'm not hearing that you have signs of problems. Some puffs on startup are normal - perhaps a feature of a horizontal boxer motor?

[nene]

Yes, it is a 3.2 and the "PUFF" of smoke is random and I am not experiencing any issues with the car running, although there is a hint of burning oil smell through the exhaust (no smoke upon acce/decel. When I check the spark-plugs, I notice that the only slightly "Darker" one in color is this one that lives below the "Oily" puddled valve. Here is a pic of what the engine bay looks like now.