help me identify that noise / issue

[1985coupe]

After some spirited driving last night, I started to feel some vibrations that got worse with time; within 10 min the grinding / tapping noises were getting louder.
This a.m. I started the car and made that short video.
It sounds like it's a belt issue -there is quite a bit of "rust dust" around the AC compressor's pulley and on both belts.

I'd really appreciate it if someone could give me some input about what the problem sound like, and what the remedy would be. Thanks in advance !



- Olivier

[Joe Bob]

Fan belt is jumping....could be the pulley.

[1985coupe]

Thanks Joe; I do see the fan belt jumping / getting loose, as if the fan pulley was indeed seized somewhat. What would be the part number if I'd want to replace (both?) pulley(s) ?
I can only find the outer one:
Pelican Parts - Product Information: PEL-RS-PUL2-BLK
Thanks !

[kach22i]

I had a similar sound, my belt was too tight, not too loose.

I had tightened up the belt so I could turn the engine while adjusting the valves. A few days later a ticking noise showed up. I re-adjusted the belt tension and the ticking went away.

[1985coupe]

I have removed both the fan pulley and the AC compressor pulley and I still get the same loud tapping that seems to be coming from the engine (block) area. like very loud valve clapping. Doesn't sound good at all...

[Paulporsche]

Chain tensioner failing?

[Trackrash]

Chain tensioner failing?

I would definitely be checking for that. I would use a stethoscope to try and isolate where the noise is coming from. (a hose or long screwdriver held to your ear can work). If it's coming from the chain cover, it's time to take a look inside before it's big bucks.
Good luck, let us know what you find out.

[1985coupe]

I tried to use a stethoscope to locate the source of the noise, but it is so loud that it is hard to pinpoint the exact location; sounds like it's coming from either the right chain housing or the right valve cover.

[Trackrash]

Probably should pull the valve covers first. Could be a broken valve spring, rocker shaft etc.
Then I'd pull the cam chain cover. Could be a broken chain guide. Either way I don't think you should run it till you check.

[1985coupe]

Thanks for all of the input. I do agree that I should not run the car under those conditions...
I guess I could put it up and as Gordon suggests start by pulling the right valve cover -my first thought was indeed a broken spring that could explain the banging -of a valve against a cylinder ?!?
Can this all be checked / done without removing the engine (e.g., rocker shaft?) ?
Thanks again.

[Hodgey]

1985coupe,
I don't want to scare you but this sounds much like the sound I had when I had a blockage in one of my oil feed holes to the camshaft lobe/valve rocker shaft area. There was no oil getting to the rocker surface and lo there was irreparable damage to the rocker and cam.....and a noise similar to yours at about a half engine speed.
Result? Complete engine strip down (as it was treated as a catastrophic failure to ensure nothing was left unturned to find the cause), reworked camshaft (stock) and new rocker....


Neil

[1985coupe]

Neil, thanks for your input, and I'm afraid you might be right

Could you hear that noise coming distinctively from the right side though ?

Well, and yes I am really scared now

[Nine9six]

Please post what you find as the culprit

[Hodgey]

Originally Posted by 1985coupe

Neil, thanks for your input, and I'm afraid you might be right

Could you hear that noise coming distinctively from the right side though ?

Well, and yes I am really scared now

1985; Co-incidentally the noise was from the right side as it happens: over #5 cylinder. Turned out to be a small piece of latex rubber that got in the oil rail peventing the flow of lubricant to the area.

(PM me for the details of how it got there)


Neil

[1985coupe]

Thanks Neil... Let me guess about that piece of latex: glove ? I do use those to work on my car(s) too and I could see how one could tear up a piece that could fall in the wrong place.

I have sent the video to a Porsche mechanic (Star Auto, Timonium, MD) but they can't say what it is and would need to look at it -so I'd need to get it towed there.

If you're right about this and I would need the engine to be rebuilt, how much am I looking into spending ? I probably don't have the skills / tools / time to do it myself, but I just can't think about spending upward of $5K to get it back on the road -and I guess there would be a lot of things I'd want to change if I were to drop the engine -clutch, seals, etc...

I will definitely post more details as I get them (996

Thanks again.

[Hodgey]

Originally Posted by 1985coupe

Thanks Neil... Let me guess about that piece of latex: glove ? I do use those to work on my car(s) too and I could see how one could tear up a piece that could fall in the wrong place.

I have sent the video to a Porsche mechanic (Star Auto, Timonium, MD) but they can't say what it is and would need to look at it -so I'd need to get it towed there.

If you're right about this and I would need the engine to be rebuilt, how much am I looking into spending ? I probably don't have the skills / tools / time to do it myself, but I just can't think about spending upward of $5K to get it back on the road -and I guess there would be a lot of things I'd want to change if I were to drop the engine -clutch, seals, etc...

I will definitely post more details as I get them (996

Thanks again.

1985; the cost is dependant upon the cause, and the condition of the rest of the engine prior to this. You don't say what kind of mileage you have on it or any other issues or big engine jobs done i.e. rings, valve guides etc etc.
A top end rebuild including machining work and the guides replacing will run around $4k depending on how much you do yourself and how much you sub out...

Neil

PS please keep us posted!!

[1985coupe]

I don't have much info about the history of the car; I bought it 5 years ago from a dealer who bought it at an auction, and it now has 100K miles on it -got it @ 77K I believe. As far as I know the internals of the engine have never been touched and don't believe the case was ever open. I would definitely replace the valve guides as most of the time I get a big black puff of smoke at start-up -not always but 90% of the time.

I understand that the engine would have to come out... but then it'd be all down hill from there -did I mention my first gear synchro ? I have Wayne's 101 projects book and I guess I could follow the instructions on how to drop the engine - I do have a scissor lift in my 1-car garage. Unfortunately if I'd go that route I wouldn't be able to tackle this issue before Fall -I will be leaving in 2 weeks for France for the whole month of September.

Is there such a place where you just drop the engine and get it worked on ?
I am reluctant to bring it somewhere as I'd feel kind of trapped

Thanks for the advice, and hope I can find the best way to get around that problem.
If any of you know of a reputable shop that could do this kind of work -in my area, Baltimore-Washington DC- that'd be a great plus. I think I am more concerned about the work being done properly than the actual cost -although I really don't have unlimited funds at my disposal... But I'd rather pay more for a job done professionally.
I am willing to get my hands dirty though -I have tackled a few projects on the car including installing turbo tie rods, rebuilding front brake calipers, installing new wheel bearings, putting a new pedal cluster (my clutch pedal broke in 2!), replacing and adjusting the clutch cable, etc... but obviously nothing really major...

Thanks again ! Will keep you posted...

- Olivier

[Hodgey]

Olivier.....you're a pro!!!!
Seriously, you have it all in the right order.....I'm sure there are reputable companies by you that will take care of you.....just DON'T send your motor to MotorMe!ster....READ THE THREADS!!!

[maxhofer]

I have a very similar noise in my '85. It started after a hard drive last weekend (car parked since then).

Please let us know when you find out what the problem is Olivier.

Max.

[1985coupe]

Neil you're too kind... Really not a pro though... But I can follow instructions
Max, I'm sorry to hear you're having the same issue
I'm flying to France today and have not had the chance to look into that problem.
My plan is to start taking it apart once I'm back at the end of next month...
Will keep you guys posted.
Thanks to all !

- Olivier