Whining noise when accelerating

dfrederick · 05-25-2006, 09:23 AM

I have a 1999 Pontiac Montana that has recently started whining when I accelerate. It stops after I take my foot off the gas pedal. It usually takes about 15 minutes of driving before the whining starts. It started about 4 months ago and has recently become louder.

Van has 85K miles.

Any ideas?

GTP Dad · 05-25-2006, 05:32 PM

Welcome to AF!!

Check and make sure that the transmission fluid is full. If you haven't changed the fluid and filter recently you may have a plugged filter causing the whining problem due to restricted fluid flow. Change the fluid and filter and add a can of Sea Foam or Lube Gard additive to the fluid. This should help. If the fluid is new and the whine continues the front pump may be going bad in the transmission.

dfrederick · 05-26-2006, 10:24 AM

Thanks for your reply. Just a clarification: The noise goes away after I release the accelerator. Would this still be a transmission issue?

dfrederick

mhall02 · 05-26-2006, 11:37 AM

Does it sound like it is coming from around the belt? My serpentine belt tensioner started whinning and it got worse, and worse (went on for a few months) and finally the pully locked up. It was most noticeable when acclerating or revving the engine. Fortunately it went out right in front of my house, threw the belt and I shut it down. Bought a new one at Advanced Auto for around $39 and one bolt holds it on. I took longer to thread the serpentine belt on than it took to take off the old tensioner and put the new one on. Mine is a 99 as well, but has 142,000 miles one it, the tensioner went at around 136,000 miles.

dfrederick · 05-26-2006, 12:52 PM

Actually, I've been suspecting that the noise originates from something within the belt drive. It sounds like a bearing is going bad. I'll see if I can isolate it this weekend.

GTP Dad · 05-26-2006, 06:22 PM

Usually a transmission will whine more under accleration. It is quite possible that the issue lies with the belt drive or even the alternator. Check everything and try to localize where the noise is coming from.

dfrederick · 05-31-2006, 08:52 AM

It seems that the noise is originating from the belt drive area. I used a garden hose to try to isolate the exact component causing the noise; however, it was difficult to determine. If I were a betting man, I'd say it's coming from the alternator.

How easy is it to replace the alternator? Can only the bearing be replaced? Is there a better way to determine the origin of the noise?

Thanks in advance.

DF

GTP Dad · 05-31-2006, 05:19 PM

You can remove the belt and start the engine without the alternator hooked up. If it is the alternator then the whine should be gone. Just don't run the van very long or the engine will overheat. If it is the alternator you would be better off with a new one. Replacing the bearings can be done but they are a press fit and for the time and effort you would have in rebuilding the one you have you could purchase another one. You may want to look for a used one at a wrecking yard they are fairly inexpensive and if it isn't the alternator then you won't have a lot of money in the replacement. Based on your description, I have to say you have found the culprit.

I had one on a Chrysler that whined for almost 100K miles and never did go bad. It was slightly annoying but I got used to it. As long as it charges and runs everything then let it whine unless the noise is so bad that you can't tolerate it any longer.

1999montana · 06-05-2006, 08:42 AM

Quote:

Originally Posted by GTP Dad

.....I had one on a Chrysler that whined for almost 100K miles and never did go bad. It was slightly annoying but I got used to it.....

I have to agree with your comment.

My Dad is a retired mechanic.

When I was a teenager and inexperienced with cars, I'd tell him that I heard this noise or that noise after taking the family car out.

His reaction; - "Turn the radio up and you won't hear it!"

Hmmm, he's still a good mechanic at 81 ....

pontiac72 · 06-15-2015, 05:06 PM

POSSIBLE SOLUTION for you: I actually have two, 2003 Pontiac Montana Vans.....Easy to do a comparison of parts/positioning ect....There was squealing going on around the belt....Replaced alot of stuff from the alternator to the pulleys to the water pump ect., Some forums suggested replacing the power steering pump ect.... The squeal seemed to stop from time to time, but eventually would start again.....SOLUTION: One thing that is RARELY mentioned on these forums is to check to see if ANYTHING if rubbing or touching the belt itself, especially INTERMITTENTLY......In our case, the CRANKSHAFT POSITIONING SENSOR, which is a plastic to plastic connector, which sits on a thin piece of metal was the problem...This is on the RIGHT side of the belt near the bottom of the belt, and is less than an INCH away from the belt.... This had somehow gotten lose or bent enough, where it was touching the belt(there had been recent work done on the car).....This rubbing caused it to whine line a banchee at times, and other times not so much.....It was extremely easy to move with one finger(which also explains it's INTERMITTENT contact with the belt), but make sure everything is cooled down....There doesn't seem to be a screw or anything that keeps this metal/plastic connector to the right(and again possibly touching the belt by shifting again to the left), so we bent the metal piece to the RIGHT, farther away from the belt(again no more than an INCH away...But it's now as quiet as a mouse.....So now we know if it happens again, what to look for......Hope this solves the problem.....

Tech II · 06-23-2015, 09:56 PM

Newbie, check the date of the post.....it's 9 years old....

pontiac72 · 06-26-2015, 07:37 PM

tech2, gee and I thought it was still 2006 ....No kidding it's many years old, but people still drive these vans around, and they may come across this very same issue....These forums are about USED cars....I happen to run across this forum, as I have this make/model vehicle...
Save your patronizing for someone who gives a rats azz.....

Tech II · 06-28-2015, 10:05 AM

Don't get your panties in an uproar.....

This forum is about give and take.......

People post a problem, we in the forum give suggestions, and hopefully we get responses, to these suggestions....

If you want to give suggestions to all the 9 year or more old posts on this forum, to people who don't even own their cars anymore, be my guest.....

donnarebeca · 06-28-2015, 03:01 PM

Quote:

Originally Posted by dfrederick

I have a 1999 Pontiac Montana that has recently started whining when I accelerate. It stops after I take my foot off the gas pedal. It usually takes about 15 minutes of driving before the whining starts. It started about 4 months ago and has recently become louder.

Van has 85K miles.

Any ideas?

I've been suspecting that the noise originates from something within the belt drive

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