Artwerks

I've done some research on this using "clicking" and "rattling", but I'm not quite certain that what I'm hearing fits either of those descriptors. I've read on some posts that this is completely "normal" for a Mezger engine. On the opposite end of the spectrum I've read that this could be cylinder or valve guide related issues. Somewhere in between I've read about loose exhaust or manifold fittings, oil sump or fuel pump issues. I probably wouldn't even have noticed this if a friend of mine didn't comment on it. He is not a Porsche guy nor is he used to hearing the unusual sounds of a Mezger engine. Regardless, now I'm concerned and would greatly appreciate some feedback from the community.
I've attached a video of the car running and close-up noise of both cylinder heads. I hear the noise on the right (passenger) side. My car is up on the lift so I was able to get a pretty good video. I think the noise is most noticeable when I move from the right head back to the left at the end of the video.
The car has just over 30k miles. I just recently did an oil change, brake fluid change, and subsequent HPDE event. The car has otherwise been running flawlessly and has no errors on the instrument cluster.


TIA,
Art

saabin

I listened to the video a few times, maybe it's hard to capture on video.. but I don't hear anything abnormal.. although my wife does tell me I'm going deaf I just call it selective hearing..

TT Surgeon

Tmistry

Seems to sound how mine sounds. Normal.

Artwerks

Thanks for responding, all. So you do hear a difference between the left and right cylinder heads, correct? The right cylinder head is louder and noisier than the left cylinder head? If that is all "normal", then what is the additional noise on the right side coming from, exactly? Any idea?

Kevin

What oil and weight are you running? I would be dropping some oil and adding 4 quarts of 5W50 oil. Where in the US are you located.

If you can get access to a PIWIS or Durametric and check the following

1) Engine hours and recent overRevs

2) Camshaft deviation.

Does your engine make a lifter noise on cold starts? Sometimes or never??

TT Surgeon

If anything maybe a slight exhaust leak.

Artwerks

Do you think tightening the bolts on the exhaust manifold would help? Do you know the torque spec?


Thanks for the response, Kevin. With all the good feedback I've heard, I intend to head your way for a software tune when I'm ready for it.
I'm in Denver, CO and I'm currently running the recommended Mobil 1 0W40 oil. I just changed it a few weeks ago prior to the HPDE event I did a couple weeks ago. I've kept an eye on the pressure and level and everything seems to be fine. It's been really hot here lately, though. Abnormally hot for Denver.
I don't have access to a PIWIS or Durametric. I'd probably have to go to my local dealer for this. I don't expect any major overRevs during my ownership which has been just prior to two years. The overRev report I got with the PPI didn't look too bad -- I bought the car.
You can measure, or there is a sensor that measures camshaft deviation? That is awesome!
I haven't noticed much, if any, lifter noise on cold starts. This is the first time I've noticed any sort of noise that concerns me about the drive train.

TT Surgeon

unless one of the bolts is loose, a leak usually needs a new gasket. the spec is 25 ft/lbs I believe.
c

V-TT

Bringing this one back from the dead.

Art, did you ever figure this out?

Artwerks

I did figure this out and you guys will be surprised what I found.

About a month after I originated this post, I went for a drive and then to the gym. Car was running perfectly. After the gym I started my car and it jumped violently and continued to shake with a horrifying sound. Something happened, I thought. Something very, very bad happened. Luckily I wasn't far from my Indy shop, so I limped the car there, probably against better judgment. You can flame me on that one. I deserve it.

Once at my independent shop of choice, the Durametric showed that the entire right side of the engine was dead (what I believe started this thread) -- cylinder misfires on all three of the right cylinders. The car continued to cause confusion for my Indy mechanic for months. They reached out to all the dealers and local indy shops in the area to try and find some help on what was going on... after all, this is a reliable and stout Mezger engine with few faults. In the end, my mechanic dropped the engine, disassembled the timing cover and valve cover on the right side, borrowed a timing tool from the local dealership, and found that the right exhaust camshaft gear had jumped two teeth!!! They reset the timing and replaced the right side hydraulic chain tensioner. Luckily no internal damage happened as a result and about $7K later, my car was running as expected again. I continue to worry about the sounds this car makes, but it seems everyone else does too.

The tensioners and the chain are not a weak point on this car and are never included in the Porsche scheduled minor or major service. So, why this happened remains a mystery. That just to say that you shouldn't jump to conclusions, because this happened to one person. The techs at the local dealership here in Denver said they've never seen this before in the entire history of dealership maintenance on the 997.

bmw_e30

wow crazy finale but glad it all worked out in the end

V-TT

While I certainly did not see that coming, it does make sense… these cars are known to spin cams, much like the leaking coolant pipes. Glad you figured it out and I am sure you took care of all the other “while the engine’s out” items.

Thanks for replying with very informative data to a very old thread!

Artwerks

Hey, what do you mean these engines are "known to spin cams"? I don't recall these Mezger engines being known for chain tensioner failures or... how else would a cam "spin"? Cam-to-drive-gear bolt failures? Variable valve timing failure?

saabin

The sleeve inside the camshaft rotates within the camshaft itself (its not supposed to do that)
The camshaft has oil passages that are used to activate the variocam, and when the sleeve "spins" it blocks (or partially blocks) these oil passages, thus affecting the cam timing.

One repair is for a machine shop to "pin" the cam by drilling a screw/pin into it to prevent it from "spinning"

Do a search on the turbo forum here for P0011 or P0022 and learn more about what happens. These are the codes that get triggered when the timing gets "over-advanced", and a spinning camshaft is ONE of the possible failure modes when that code is generated.