924Board.org

[B]

Hey everyone

After hooking up my new walbro fuel pump, I went to start the car up to test it and look for leaks - thankfully it worked and so far no leaks - the car was not the most enthusiastic to get started - especially because it had sat for a while without starting.

When it started it let out a strange crunchy sound once or twice and then a high pitched squeal - the squeal I recognized as a loose alternator belt the crunch not so much. It was muffled behind the squeal and only happened once or twice.

I let it alone until the next day, a little more energetic little to no squeal but a little more crunch. I checked the belt and tightened things up and tried again.

Now no squeal but holy crap that crunchy loud rocks in a tin can sound will not go away.

I don't know how else to describe it besides loud motorized marbles or rocks in a tin can sound.

Now that the long story is over - It sounds like it could be an alternator bearing but I am not sure

Is there anyone else out there that has encountered something like this? any thoughts on what it could be? I am kinda nervous to try to start it again in case it may be something worse.
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1979 924 n/a
BAE turbo
5-speed snailshell

[B]

I also thought about trying to start it with the alternator belt off - I realize the water pump would also be disconnected, but I thought I might be able to for a second or 2 just to see if the sound is there ...
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

[Kevin D]

If you loosen the belt tension and spin the alt pulley by hand, how does it feel? If it is the alternator, it should be pretty obvious when you try and turn it by hand.
_________________
'88 924S 3L 6sp RedRat
'92 Duc 900ss
'02 Duc 998 Carbon
'72 RD 350

[B]

it spins - but not very well appears to be a bit of a drag to it I had a spare that was no good and it spins freely - much better than the one on the car now

neither has noise

thanks
Sean
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

[fiat22turbo]

perhaps the timing belt tensioner?
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[Harm]

Checked the waterpump for play at its wheel?
When its axle wears out, the rotor inside causes to hit the block and will sound horrid…
It can also stop the belt: loud high pitched squeal.
Easy check:
Remove the belt and wiggling the pulley by hand feeling for any play…
When worn it will probably loose coolant around that axle.
HTH
_________________
Porsche 924 NA 1982 LY7A/A3A3 _ Greater driving pleasure never harmed anyone.

[Rasta Monsta]

+1 on the tensioner.
_________________
Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[B]

the water pump seems ok no wiggle that I can see or feel - on to the tensioner next

thanks everyone
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

[B]

the tensioner (which I forgot is relatively new 1-2 years) seemed fine - did not rotate too freely and made not noise when it was rotating

I am going to look at the turbo next to see if something got in there - I have no idea what

otherwise I am completely lost - I was fairly certain it was going to be belt drive related -

could it still be the alternator?

I am hoping it is not an internal part -
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

[B]

I think this is a similar sound
http://www.youtube.com/watch?v=zl-AGOplM-8
(hopefully this link works) maybe this type of sound and it increases with engine speed

I may try to start the car without the water pump/alt. belt hooked up to see if it makes any noise - hopefully that will not be bad for a few seconds

any thoughts?
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

[fiat22turbo]

Could just be something stuck and rubbing on a belt or pulley.

The timing belt tensioner should spin freely and without noise. Also new parts doesn't always mean they are good.
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[B]

Thanks Stefan

I was not sure about the tensioner or the alternator - neither spin very freely - a few rotations max then slow and stop

I found an old tensioner that I took off and it spins great but it does have a bit of a grinding sound to it - but the difference between the two as far as spinning is night and day
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

[fiat22turbo]

Yep, both should spin pretty well if you give em a good fling. If they don't? That's not great. Luckily the alternators and tensioners aren't too expensive or hard to find, except maybe 4th of July weekend
_________________
Stefan
1979 924 Carrera GTS (clone-ish)
1988 944 Turbo S (Silver Rose)

[B]

Thanks Stefan
I think I will give a couple of places a try tomorrow. The alternator was not a stock type it is a summit 100amp - so I will see what they have for that and I think I may have a line on a tensioner as well - hopefully that will take care of it

thanks again

Sean
_________________
1979 924 n/a
BAE turbo
5-speed snailshell

[B]

ok so the alternator tested ok and did not make any noise at least not at auto zone

the noise was not there when I took the belt off of the alternator, and waterpump - so I did not here anything for the minute or two that it ran - so I might assume the tensioner is ok

After I tested to see if the tensioner was making the noise - I reconnected the other belt and the noise returned instantly

Now I am really out of ideas

could it be

the water pump - it is really loud though and I do not see any signs of leaking

turbocharger I do not know why it would be - but I suppose it could be

something else engine related?

any other ideas or suggestions would be greatly welcome and appreciated

Sean
_________________
1979 924 n/a
BAE turbo
5-speed snailshell