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Hoboceratops · Joined: 16 Aug 2006 Posts: 156 Location: Atlanta, GA

So I just got the head gasket, oil cooler seals, timing and balance shaft belts and various other minor things replaced in my 924S this week, so now it runs great; lope in the idle is gone, no smoke, much more smooth running overall.

BUT

and this is a big, round, full bodied but -

The engine is whining like crazy. Higher the rpm, higher the whine. Little reading up, possible the mechanic tightened the timing or balance shaft belt (the belt's been off for who knows how long, possibly years) too much? Or could it only be the timing belt?

Any tips would be pretty great, I'd like my belts to not explode on me.
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1987 924S: Very much in love with it, even if it's all finnicky

968rz · Joined: 21 Aug 2006 Posts: 537 Location: S. E. Wisconsin

It could be any of the belts. It's not that hard to loosen the acc belts (alt,ac.ps), but if you just had the work done I would take it back and ask the mech to check it out (if he cares about his work he should).
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Rick
79 924 coupe Petrol Blue 3spd auto (wife's DD)
93 968 coupe Amazon Green 4spd Tip (my DD)

Hoboceratops · Joined: 16 Aug 2006 Posts: 156 Location: Atlanta, GA

The acc. belts are fine, just checked them a little while ago, as my PS pump is loose on the mount and that belt is always finnicky. Not the problem, so it's gonna be the balance or timing then I think. >.<

Gonna pop the covers off and check the tension on the belts with the finger twist as a base and loosen it a touch to see if I can drop the whine, then take it to the shop tomorrow.
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1987 924S: Very much in love with it, even if it's all finnicky

Paul · Posted: Mon Nov 06, 2006 1:29 pm Post subject:

The most often cause of this whine is a balance shaft belt that's way too tight or the balance shaft idler pulley is installed too close to the balance shaft belt.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

Hoboceratops · Joined: 16 Aug 2006 Posts: 156 Location: Atlanta, GA

Lizard · Posted: Mon Nov 06, 2006 1:39 pm Post subject:

I found that if you tensioned the belt with turning the tensioner clockwise to tension that I could not get enough space between the idler roller and the belt, If you instead turn it counter clockwise to tension that you get alot more room of adjustment for the idler roller and that the whining noise almost completely disappears.
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3 928s,

Paul · Posted: Mon Nov 06, 2006 1:52 pm Post subject:

It's labeled "Balance Belt Idler Roller". It should just barely touch the belt.

Courtesy of Clarks Garage:

_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

Hoboceratops · Joined: 16 Aug 2006 Posts: 156 Location: Atlanta, GA

A'right, thanks a bunch you guys. Down to the garage I go.
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1987 924S: Very much in love with it, even if it's all finnicky

timstar92404 · Joined: 22 Sep 2004 Posts: 2075 Location: richmond BC

the balance belt is also suppose to be pretty loose, I just tightened it just enough so it doesn't come off or slip. If you make it a little too tight the noise will be much higher.

I'm taking my car to a porsche shop to have it all tensioned by a professional with the 9201. Probably a good idea to take to a shop with the porsche tool to get the belts adjusted, it shouldn't cost much (maybe 1 hour labour).

when I had my belt adusted wrong it had a really loud belt whine I could hear inside the car with the hood and doors closed.
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78 924 sold.
85.5 944

Paul · Posted: Mon Nov 06, 2006 2:02 pm Post subject:

I recommend that you take it back to whomever installed it.....
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

Hoboceratops · Joined: 16 Aug 2006 Posts: 156 Location: Atlanta, GA

Yeah, just gonna loosen the B.S. belt a touch and get it into the shop tomorrow.
_________________
1987 924S: Very much in love with it, even if it's all finnicky

Paul · Posted: Mon Nov 06, 2006 2:11 pm Post subject:

The tension may be fine, check to see if the idler is causing the noise (since it's smooth and the belt has teeth, when the belt hits the idler, it howls).
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

Hoboceratops · Joined: 16 Aug 2006 Posts: 156 Location: Atlanta, GA

Err.. sorry, that's what I meant
_________________
1987 924S: Very much in love with it, even if it's all finnicky

Paul · Posted: Mon Nov 06, 2006 2:15 pm Post subject:

The purpose of that idler is to keep the belt on the balance shaft sprocket....
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

Lizard · Posted: Tue Nov 07, 2006 2:11 am Post subject:

iirc the manuals say that you should be able to fit a feeler guage between the idler roller and the BS belt. though I cannot recall the thickness of the feeler guage.
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3 928s,