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clunk clunk clunk...LONG post,please help!!!


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11eleven
New User

Jan 11, 2008, 2:17 PM

Post #1 of 3 (4042 views)
clunk clunk clunk...LONG post,please help!!! Sign In

Hi,

I have a 1990 Pontiac Bonneville SSE that is an amazing runner, but has a few mystery issues…
When I bought the car 4 months ago it had about 174k miles on it, and I have since put another 18k on it. (I drive an average of 120 miles a day round trip for work!!!) as well as having taken it on a few trips.

Issue #1
When I purchased the car it made a funky clanking noise, (kind of sounds like a big cow bell or someone clanking two pieces of metal together) and I was told it was the a/c compressor. A few drops of gear lube every other day on the a/c compressor greatly quieted the clank.

The noise has always driven me absolutely crazy, but as of the last few months it has gotten much worse, and the gear oil no longer makes a damn bit of difference! (I’m beginning to wonder if it ever really did!?!)
I have done countless hours of research and have studied the repair manual well. I have had several opinions from several mechanics, one said it was the a/c compressor, one said it was the a/c clutch; one said it was the alternator, and another said it was the water pump. A few weeks ago a friend of mine who has some mechanical experience gave it a listen. I had just told him that through MY research I believed it had something to do with the harmonic balancer.
He listened and looked with the engine running, then gave it a look with the engine turned off. IMMEDIATELY he said, “Whoa! You have a huge chunk missing out of your harmonic balancer!” and he was right!
There is a huge chunk of the rubber ring piece missing… I’d say its approximately 1 ½” wide at the widest point and a half inch wide at the narrowest (kind of shaped like a pie slice).
My question is this… from everything I’ve read on the net if your harmonic balancer is this damaged there’s no way in hell the car is gonna put out another 18k without something seriously going wrong. So is this TRULY what’s making the noise?

Here are all the detailed facts I have personally gathered about the clank:

It is obnoxiously loud at idle with the car in drive and foot on the brake
It is 50% more quiet at idle with the car in park no foot on the break
It is damn near SILENT at idle with the car in neutral no foot on the break

Both the air conditioner and heater work fine, the a/c is cold, and the heat is hot…
HOWEVER I was having issues with the fan being intermittent…some days it would blow air through the vents, other days nothing.
And as of the last 3 weeks, it hadn’t blown at all, until last night when I hit quite a large pothole on the front passenger side and all of a sudden, the fan decided to work again and has worked ever since!! (Is this getting strange or what???)

It is obnoxiously loud with the a/c OR heater turned off
About 50% more quiet with a/c OR heater on
About 75% quiet with the a/c OR heater on defrost mode
I’ve noticed that when I step on the brake, whatever gear I’m in, the clank is much quieter.
The sound decreases by about 75% when the triangle thing on the front of the a/c pulley kicks in and starts to spin (sorry not sure what that thing is called) as soon as it stops the car is loud, of course, unless it’s in neutral.
I have read that if you are able to turn the balancer at all with your hand that this means it’s bad and needs to be replaced? Not sure if this is even true, but if it IS, I am able to rotate the balancer approximately 4 inches front to back with my hand. And where it stops when I do this it makes the same clank (sounds like the same anyways) as the constant clank it makes running.
When the engine is running it appears that the balancer has a slight “wobble” to it, but nothing major.
When I tap the accelerator it makes the clank very loudly upon deceleration.
And when I turn the engine off, the clank is the last thing you hear coming from the engine when it shuts off. However, it does not make the clank upon starting the engine.

Issue #2
When driving at speeds of over approximately 30mph, it sounds like there is a jet airplane lodged in the front passenger side tire. It makes the plastic trim around the interior of the passenger side vibrate, of course resulting in more obnoxious noise!
It goes away when I turn right, gets louder when I turn left. It is often so loud that I can barely hear what my passengers are saying to me!
About a month ago I was at a stop sign preparing to turn left. Traffic was horrid so I had to really stomp on it to make it across without getting hit.
As I stomped on the gas the right front tire felt like it “bounced” or “skipped” instead of actually rotating to catch up with the other three.
I was told by the shop that changed my oil last that my axle boots were torn, could this possibly be the reason for the jet noise?

Ok, now here is an interesting coincidence that I just can’t ignore…

Ever since having my oil changed at this place my poor car has been on the downhill slide. The clunking noise has been there since I purchased it, so I can’t point a finger for that one…BUT the fan stopped blowing about 2 days after seeing them, the jet plane noise started the day after seeing them, and I have blown countless fuses and had tons of weird little things come and go.
When I got home and popped the hood I found that they had not even screwed my oil cap back on, and one of my biggest complaints is that my gas mileage has decreased from 24mpg to 18mpg, a HUGE decrease when gas is as pricey as it is right now.
I don’t really know if the oil change is at all related to these problems or just coincidence, just thought I’d mention it as I’m trying to be as specific as possible.

I live in a VERY small town and have already had my fair share dealing with the crooked mechanics around here! I HATE the thought of taking it in to get the a/c compressor replaced and the problem having been the balancer! I would much rather buy the parts and do the work myself.


If anyone has a list of what harmonic balancers are compatible with my car I’d greatly appreciate it. There aren’t many junk yards around here for me to pull one from, so the chances of finding a junked 90 Bonneville SSE are slim, and I just can’t afford the $150 Kragen wants to charge me for a refurbished one.

Many thanks for taking the time to read my super long post, sorry it was so long but I just wanted to make sure and be VERY specific and detailed so that hopefully I can get the right answers!

Any help or advice is much appreciated!


Double J
Veteran / Moderator
Double J profile image

Jan 11, 2008, 3:21 PM

Post #2 of 3 (4040 views)
Re: clunk clunk clunk...LONG post,please help!!! Sign In

howdy

call your local junk yard,they will have an interchange,let you know what fits what..

yes.common problem with the balancers on these years...seen many.it should be changed before you keep driving it...it does what it says. (another name for it is "vibration damper"
the jet airplane noise sounds like it could be the hub bearing assembly....
also if the boots are torn,they'll need replacement and you should have the cv joints checked for wear,especially since the car has been driven with torn boots.

on the blower problem,sounds like the blower motor is worn and needing replacement.
simple stuff.....
post back with results..

Jim


(This post was edited by JIM N on Jan 13, 2008, 3:18 PM)


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Jan 12, 2008, 5:02 AM

Post #3 of 3 (4036 views)
Re: clunk clunk clunk...LONG post,please help!!! Sign In

Ditto with JIM. May I add that the compressor is two bushings in compressor only in use when compressor is engaged and one sealed bearing in clutch which is only in use when A/C is not engaged. That is.... with A/C off - you need to unplug it as it can kick on with defrost, and the whole thing is essentially a blank pulley. You can't lube any of the bearings. What may have happened is a drop of oil on belt shut it up. Belts can make wild noises with nothing else wrong. Spray them with WD-40 and if that shuts them up instantly they really must go.

The problem with balancer must be addressed. The A/C is a hard load on the belt and would exaserbate any other problem with a pulley or the belt. For now I don't think this is A/C anything.

Used parts can be had from anywhere, any time of year. There is an inventory network. Where are you? A balancer weighs a bit so shipping could be up there. I can give you phone #s for used right from MA and the part will be found near you,

T







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