help me identify that noise / issue

[williecoyote]

Bon Voyage.

[1985coupe]

Well things are pretty much where I left them last time around. I have not yet started to dismantle my special piece of German engineering but will probably start doing this early next month -major deadline for me at the end of Oct.

Please share your personal experience if you do (did) happen to have similar issues.

I feel confident that with the help of this group of highly committed Porsche enthusiasts I shall find a way to the heavens of my air-cooled boxer engine

Thanks to all !

[1985coupe]

OK the weather is starting to get better so now would be the time to think about getting my 911 back on the road.
Not sure where that video clip went to here it is again:
CIMG3805.mp4 video by frenchsailor - Photobucket

I will soon start taking things apart and will document things. I have not yet been able to find a reputable mechanic who wouldn't rob me so it looks like I'll have to make the plunge and get my hands dirty instead of going sailing...

As usual any and all help is greatly appreciated.

- Olivier

[pdx930]

I'm no expert in these things, but the accumulation of rust dust on the belts and pulleys and the jumping fan belt is interesting. Is it possible that something dropped down in between the engine cradle and the crank pulley and either bent or knocked the pulley loose so that it is rubbing on the cradle? Does the crank pulley run true?

[1985coupe]

That's an interesting proposal and hadn't thought about something having broken down and fallen in the guts of the pulley / shafts arrangement and screw something up...

That knocking noise originates more towards the right side, that is quite certain, and its frequency seems about 1/3 or 1/2 that of the engine.

Wonder if there is a table somewhere that provides information about the frequency of the various moving parts of the engine as a function of engine RPM -a bit similar to what is provided for transmission gear ratio. That could maybe help pinpoint to a more likely culprit -short of a 3.2l 911 engine expert with golden ears. That is before I start taking that thing apart... Can't afford to screw things up...

Thanks again for the input -great suggestion.

- Olivier

[schnellmann]

After watching the video, and reading that you already ruled out the AC compressor by removing the belt, it's almost certainly a 1/2 engine speed tick. There is only one thing in your motor that spins half speed, and that's the cams.

Before pulling the motor, why not just remove the upper and lower valve covers? Maybe you'll find the cause right away. If it's a broken spring or broken rocker, it will be obvious when you examine the cam tower.

Also, while you have the valve covers off, check the head stud nuts. Make sure they are all there and torqued to spec. Sometimes a broken stud (or two!) can cause a ticking noise because the head and the jug are gapping and then slapping together when the piston moves through the cycle. Broken studs are not unheard of in the 3.2s, and worth a look.

Removing the valve covers will cost at most the price of a gasket kit. I'll be curious to know how it goes...

[DRACO A5OG]

What brand of oil are you using?

Just a thought but maybe the Carrera Chain Tensioner Oil lines are clogged. I recall during my PPI that was one of the first things Tony Callas swapped in my baby.

[1985coupe]

OK I think I have collected enough information with the help of you guys to be quite ready to start taking things apart. Valve covers will be the first thing to go and I will report on my findings.

I have been using Castrol GTX High-mileage 10W-40 -the car has just under 100K miles. I live in Baltimore, MD, and the car is always garaged -so it rarely goes below freezing; summers are quite hot and humid... I drive maybe 3-4000 miles / year.
I have also been using Mobil 1 for a while and wanted to go fully synthetic but I am not quite ready to start chasing oil leaks... Although this should be the one I'd like to use.
Maybe I should start an oil thread -just kidding

Many thanks for all who contributed to this thread; I am about to take the plunge and get my hands dirty and will feel more comfortable knowing that help will never be very far, time-wise at least. This is once again great to have all of this concentration of P-car enthusiasts and experts.

I will report as soon as I have the valve covers off; might have to wait for this week-end -or next, or the one after... So many projects around and inside the house as well... Not counting recommissioning the boat after a loooog winter...

Thanks again -and you can always keep on making suggestions. Best to all !

- Olivier

[SCWDP911]

good luck! Hoping for the best for you and the car.

[1985coupe]

So I drained the oil and found a lot of metal shavings on both drain plugs.
I could only get about 4 quarts out though, mostly from the oil tank. I could retrieve more metal shavings from the case drain hole with my finger and attempted to help get those out by adding oil through the oil fill, but it was only accumulating in the tank and would apparently not make its way to the engine... Sounds like an indication of a major blockage...

Looks like I am in for a rebuild or a new engine... I'm quite devastated...

As usual any advice is greatly appreciated !

Best,

- Olivier

[NOLAsc]

Olivier,

What happened? Were you able to fix it?

Shawn

[1985coupe]

I haven't had the time or money to get my 911 fixed. I am reluctantly putting it up for sale as is.
Bring me your best possible offer. From what I now understand we are looking at an engine overhaul / rebuild due to probably thrown out bearing -lots of small shiny bits of metal that are magnetic...
Vehicle located in Baltimore, MD.

[Mrame]

A few years ago I had a similar sound coming my engine after an aggressive drive, during that drive I missed a shift and bent some valves. I really hope this is not what happened to you. Very expensive mistake !!

[maxhofer]

So sorry to hear that Olivier. I am in the same situation as you are...my wife is putting pressure on me to sell my car as it is (very similar problem as yours)...but I still cannot see myself without my precious!!!

[orlandotarga]

I have the exact same noise coming from my engine as well. Did anyone find out what it was?