SC Tensioner Upgrade = Loud Whirring.

[marcar911]

After installing pressure fed tensioners on my 82SC, I have noticed a constant loud whirring sound from the engine.

I have read other posts of this phenomenon and I am wondering if this is someting to be concerned about.

To characterize the volume of the whiring, with the stock muffler you could not hear the exhaust note over the whirring. With a dual out Dansk, under light/medium throttle, the whiring and exhaust are about the same level.

I am considering pulling the cam covers and examining chain tension. Is it possible for the chain to be too tight?

Thank you,

Marlin

[450knotOffice]

I've got an '84 Carrera and mine whirrs pretty loudly but it always has. Doesn't seem to be aproblem for my engine.

[aigel]

There definitely should be no sound that is louder than the stock exhaust. Anything that sounds different than a well oiled sewing machine is not a good sign.

Describe the noise some more. If it has any grinding or rattle to it (muffled), it may mean that your new tensioner(s) are no good. Try to pinpoint the noise by using a long screw driver or breaker bar as a stehtoscope and put it on the chain covers. (Careful with a running engine there!)

The carrera tensioners are silent, just like the ones you took out.

Did you mess with the chain ramps? Maybe something is just slightly rubbing.

George

[Crowbob]

It could be the alternator bearings are going.

[spydr32000]

Sounds to me that some how your chain alignment is out. This is one of the few things that will cause a whirring noise in the engine, especially, if it has occurred after changing tensioners.

The other thing is of course is the alternator, or any belt driven accessories, these are easily eliminated by removing each relevant belt one at a time and listening for the noise after removing each belt!
Regards Mike

[marcar911]

To descibe the noise some more, it is a definte whine similiar to a sqare cut gear noise.

There is no grinding or rattling consistant with a collapsed tensioner. The resultant sound (after upgrade) is quite different as compared to the sound before the upgrade. Before the upgrade, I had one collapsed tensioner that was quite noisy cold.

I did not touch the ramps or chains. Just replaced old tensioners with new. I did hold the chains tight when installing the new tensioners before pulling the pins.

Do the tensioners have a one way valve that hydraulically locks them in the furthest out position attained? Meaning is it possible to preload the chain to much prior to pin pull? Or, will stretched chains make noise?

It does not appear to be the alternator - just in the chain housings. I definitely do not have a sewing machine sound either.

How would one verify chain alignment as proposed above.

Thank you,

Marlin

[aigel]

Marlin:

Ok, you know what a bad tensioner sounds like!


"Do the tensioners have a one way valve that hydraulically locks them in the furthest out position attained? Meaning is it possible to preload the chain to much prior to pin pull? Or, will stretched chains make noise?"


They are somewhat "locked" mechanically, however, they bleed off very slowly to where the tensioner is just nice and snug. They work like shocks, practically. So, no, you can't preload them during installation where they would not return to their ideal position.

The chain alignment is not changed by the tensioners. The alignment is between the intermediate shaft gear and the cam sprocket. Only if you take the cam sprocket off (or more), you will need to worry about it.

If your car wouldn't be an 82, I'd say you forgot the spacer for the idler arm. But your idler arms are already the ones with the wider base (80 and later).

I am clueless. I do not have enough years with these cars to know what the noise could be. If it were my car, I'd just take the covers off again and see what's up.

Do both sides whine? Stuipd question: Did you forget anything in there? It happens to surgeons too, sometimes.

George

[marcar911]

I will have to check into if the noise is more prominant on one side or the other. At the current time, it appears to be coming from both sides.

Thank you for the tensioner info. It is good to know the tensioners will find the ideal position. Saves uninstalling and reinstalling them again.

I agree, I may just have to pull both chain covers and inspect to gain more insight.

Other than the tensioner install, the only other change performed that day was the oil. Filled up with 10w-40 semi synthetic changing away from 20w-50 non synth. Probably not a factor in the noise equation...just considering all aspects.

Marlin

[350HP930]

I too suspect a problem with the chain or tensioner gear alignment.

[marcar911]

Does an easy way exist to check chain alignment? Is this best done by a mechanic i.e Porsche dealer?

During the process, the tensioner idler arms were not removed. I tried to remove just what was necessary - the tensioners.

Before the upgrade, it appears as if both chains were potentially alot looser. The resultant chain tension appears to have revealed the issue (or problem).



Marlin

[Matt Smith]

My car immediately made a different noise when the pressure-fed tensioners went in. Not too loud though, but definately a more pronounced whining noise, a 'gear driven' sound if that makes sense.
At the time of install, lots of people on this board were adamant this was normal, and I'm inclined to agree in my application. Sounds good anyway.
Yours sounds louder?? Maybe your exhaust is too quiet!
Just kidding. Listen to all the wise advice.

I'm not hugely impressed with the carrera tensioner upgrade, as mine has shown 'issues' with pressure on the right hand side shortly following startup. Time to pop the covers ..again...

[aigel]

Originally posted by marcar911
Does an easy way exist to check chain alignment? Is this best done by a mechanic i.e Porsche dealer?

During the process, the tensioner idler arms were not removed. I tried to remove just what was necessary - the tensioners.

Again, the sprocket and the intermediate shaft gear are the two things that need to align and you didn't change any of that. The idler arm has enough travel on the shaft to go wherever it needs to be, so even if you would have taken it off, you'd still be fine.

You should post your question on the engine rebuild forum, where the engine builder gurus and experienced mechanics hang out. I still doubt you should expect a noise that's louder than stock exhaust. Maybe your chain ramps got beat up and now make more noise with the better tensioned chains, I dunno. At this point I'd be in there.

George

[juanbenae]

is it more pronounced when the motor is 1st started and not warm? thats when mine did it, after it was warm no mas. it was never louder than the exhaust, but i could hear it. don't notice it anymore.

[john walker's workshop]

is it cold in iowa still, like around freezing? i've noticed some whirring when the engine was real cold, for a few minutes. other than that, i would pull the covers again and give a light pry with a screwdriver to see if they ever pumped up. i've had 2 recently that would not bleed out. i use a pump style oil squirter can with a hose and banjo fitting attached to bench bleed the suckers. if it won't firm up, it ain't going in.

[marcar911]

The whiring is not temerature dependant. Sounds pretty much the same cold vs. hot.

The sound is RPM dependant. The higher the RPM, the higher the pitch the whir / whine as one would expect. A "gear driven" sound is accurate as Matt has stated above.

Sounds like in the near future I will be pulling both covers as time allows paying close attention to if the tensioners are pumped up.

I will also look into the alignment of the idler sprocket. If memory serves, this arm can float on the pin(?) and is located on one side by the cover and the other side by the tensioner arm around the pin.


Thank you,

Marlin