C900S weird tin-y chatter coming from under the hood

All,

Classic 900S owner looking for some help - The sound has grown progressively worse in the last two days, now there's a slight squeak associated with it - theres a clinking/pinging sound coming from an area very near the alternator, sounds like a thin piece of metal being tapped, similar to the sound a pot lid would make - the sound speeds up with the motor and at times I think I can feel it in the steering column and clutch pedal. I need to narrow down the culprits as I live

40 miles from a Saab specialist. If it's the alternator that's gone bad I can take it to a BMW mech I trust. I had a monster service done 5k ago - replaced the auto trans with a manual, CV joints, head gasket, timing chain, brakes, 90k tuneup. Any advice greatly appreciated !
Reply to
Judd Austin
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My first guess would be alternator or water pump bearing, but I'm puzzled by the fact that you say you feel it through the steering/clutch

- you are very unlikely to feel either of these things.

Just in case it is, spray a little WD40 onto the alternator bearing. Does it change? Spray some more onto the water pump bearing. Change?

Reply to
Grunff

AARGH! please don't put WD-40 near anything important. It's a water displacer and a solvent, not a lubricant. Short term apparent improvement in exchange for a shorte life is never worth it.

Reply to
Dave Hinz

But if it's knackered, and quietens down with the WD-40 then it needs replacing anyway surely :-)

Mike

Reply to
Mike P

Killing the patient to get a diagnosis isn't a good practice though, is it?

Reply to
Dave Hinz

Dave - I know that - but this is one of the few things it's ok for, testing whether a bearing is squeaking. I suggested it because it's the one suitable thing most people are likely to have.

The other thing WD is suitable for is spraying all over/wiping down my tools. Keeps them nice and shiny.

Reply to
Grunff

Problem is, if that's not a squeaking bearing, dissolving the lubricant out of it isn't going to help it much, is it? Takes "OK now" to "bad soon" if that solvent gets into where the lubricant is.

OK, I'll grant it that.

Dave Hinz

Reply to
Dave Hinz

ISWYM, but I can't say I've actually experienced failures as a result of doing this - and I've done it plenty of times when trying to diagnose squeaks.

It really isn't bad stuff, as long as you recognise its limitations. It's great on exterior metal work (hinges on the barn doors, stables etc.), great on tools and other bits of workshop machinery (drill press, lathe, grinder).

It's a poor lubricant, and a very poor substitute for penetrating oil.

Reply to
Grunff

Turns out to have been the Harmonic balancer - completely seperated. It took out the 4 month old waterpump as well. I understand it could have been worse - oil pump is nearby. This has been a VERY expensive year for old greenie

$4000 in March, converted the car to a manual trans (auto died at 94k) this included 90k service, new timing chain, head gasket, fixed drivers seat, antenna mast, new front brakes CV joint/boot. $350 in April, Heater core dumped into the drivers compartment $1000 in June, new alpine head unit, speakers, and Eclipse 100w 4 channel amp $450 in july, Dunlops gave way to a set of Michelins $550 for the harmonic balancer/waterpump

Keep in mind I bought her for $6k early last year...

Thanks

Judd

'94 C900S Convertible 102k

Reply to
Judd Austin

Glad you've fixed it.

I wouldn't have thought this was economical to do. I've done it once, and it took quite a lot of time to do. But that was done as a hobby. If you're paying someone to do it, ouch!

Reply to
Grunff

Depends how clean the rest of the car is. And what else has been spent over the years. If it runs fine the body work is solid, and that $4k is the difference between a good car that needs work, and a newer car that is now fairly high mileage, and an unknown quantity. I would be tempted.

Reply to
MeatballTurbo

Yep. That's where I ended up. this is a California car and in fine condition -body/paint is flawless, compression is fine, doesn't burn oil, idles right, top is fine, interior is in great shape - seats and carpet are clean, no cracks on the dash etc... It's just that the trans went. The cost to replace the auto with either a used pull or rebuilt was about $1500-$3500 and it came with a 1 year warranty at best. Absolute Saab in Encinitas, CA. offered a Manual conversion for $3000 with a 3 year warranty. I figured I could get better gas milage with a manual (it now cruises at around 3k RPM @75mph and gets approx.

24 mpg freeway)and easily another 3-4 years of use out of it. As I described I took care of a lot of other things while they were at it. The car is my daily driver, I put down 80-90 miles a day.
Reply to
Judd Austin

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