PontiacBonnevilleClub.com

If you haven't read my intro post, I recently bought a 2004 SE with 137k mi and started fixing it up.
This is one of the more annoying noises I've had with any vehicle although thankfully it hasn't been a 'grand stranding' incident involving a tow truck yet.  The car runs/drives and generally operates pretty well, but there's a rather loud clanking metal noise that only occurs when turning right or banking right at speed.  It resembles a tin can dragging/bouncing along the axle or road, fan hitting.  People do notice....we're calling it the Pedestrian Early Warning System-Half Duplex (PEWS-HD).
A video link you can hopefully use (remember, it does not make the noise going straight or turning left - NOT heat/dust shields, rocks, bearings, axles, fan shroud, COULD BE: oddest cracked flexplate): https://www.icloud.com/photos/#02PUte0R ... X9b82UxCCA
This long story is getting longer and possibly more time-consuming/expensive than most mechanical repairs I've ever undertaken myself or paid a shop to do.
We've had the car up in the air at my place a few times trying to diagnose the problem.  The shop that rebuilt the transmission that also does driveline work couldn't figure it out although they didn't spend much time on it. Their alignment shop looked at it twice. Two of my mechanic friends looked at it with me.
At least five different mechanics and a number of other very knowledgeable people haven't figured it out.  Up until this past week, it hasn't cost me anything, but time and favors from friends.
Without a solution and during a moment of impatience, I left it at a busy Firestone after Thanksgiving and let them see what they thought.  The initial cost was $10 (inspection/tire rotation coupon - yes I'm aware that's how they get money for add-on air filters, wipers, and other easy jobs.)  The location was convenient for me.  I got a call later that day and they said it was the right CV joint.  It sounded like no other CV joint or fwd axle I've ever heard before, but they know more than me, right?  I heard a reasonable price and that they would have it done the same day.  I got a call a few hours later and they said it was almost done, but there's still noise from the transmission.  I thought maybe I had heard a constant sound while on the highway so dismissed the new noise plus the rebuild has a warranty.  I went to pick up the car.  As soon as I drove out of the lot, the clanking was evident on turning right so I went back and had the tech ride with me.  He said they thought it was the cv/axle, but now they think it's the transmission.  I was able to get him to admit that they weren't sure.  I don't think anything was wrong with the cv joint.  The manager agreed to 'make it right' once the transmission shop had a look at it.  I have heard a sound that has some similarities some years ago from a transfer case, but certainly not as loud and not as hard to pinpoint.  It could be a really odd flexplate crack that the shop didn't notice when doing the rear main seal. The flexplate shouldn't be affected by a turn.  At one point I thought it might be a cooling fan somehow hitting the shroud off and on.  We quickly ruled that out.  The transmission shop knew about the noise and even pointed it out when I picked it up.  I bought it that way and didn't think it was more than a dust shield especially since it only happened on right turns.

I've watched the video and even with your post describing how everyone has failed to diagnose this, I am very confident I could figure this one out. However, I don't think you'll get your answer from a forum post. If it were in my shop, I'd have it up on the 2 post lift, and then put a load on both front control arms as if it were driving. However, based on the video, its not a rhythmic rotational sound as it doesn't start immediately on your acceleration. Seems like something is dangling, although this can't possibly be true considering how many people have looked at it. Maybe a GoPro mounted in the wheelwell?

It definitely doesn't sound like a CV axle, that shop just wanted a quick buck. And there is no way its the transmission itself.

I have provided no useful information, but wish you the best of luck.

I'm picturing something in the bell housing that needs some momentum to fall to the left where it gets knocked around by the flexplate.

Oh, how's the starter doing? One time, whatever pulls the Bendix back failed and when it turned the one way, it would flop out and intermittently catch the flexplate.

J Wikoff wrote:I'm picturing something in the bell housing that needs some momentum to fall to the left where it gets knocked around by the flexplate.

Oh, how's the starter doing? One time, whatever pulls the Bendix back failed and when it turned the one way, it would flop out and intermittently catch the flexplate.

That makes a lot of sense, I'd definitely be looking into that.

Thank you for your ideas. Maybe I'll tape an old phone under the chassis in various spots to see what noises it picks up on a recording. The starter works well and doesn't seem to be affected however it's definitely something to monitor. The alignment shop said the only place that was 'shiny' was the ring gear on the flexplate which is normal. They looked it over quite a while and this little independent shop has been around a very long time. Their last comment was to drive it since it won't get better. At that point, we can maybe figure it out.

I go to Firestone today since the manager said he would refund part of the cost. Why they didn't do the refund over the phone is a concern.

Update, I was able to get it to do the noise while totally stopped in park. Reving the engine did make the noise alter slightly, but it really did it at idle most which could mean it gets torqued differently with higher RPMs. We drove it around on Sunday and were looking at all the empty car lots. While driving behind the Ford dealer on a left tilting slope in the lot, the car started making the noise. I stopped and it continued but much quieter. I'll try this again soon and record the noise while listening carefully with a stethoscope. I also got a P1887 code on the way home. TCC switch it seems. I cleared it and we'll see if it returns. Hopefully, that's not the proverbial air pressure sensor like the shuttle columbia's clue.

Btw, Firestone gave me a little back, but I had to go there and there were a few games played. Overall they did spend some time on it, replaced the cv axle, and did an alignment. I kept the lifetime alignment.

Must be so frustrating, to add to the other advice;

Since the noise is also heard at idle, try removing the belt to see if that alters the noise.
Separately, many years ago I experienced an elusive noise which was due to a loose torque convertor bolt.

Update, apparently that dealership parking lot tilt is special in severity since I couldn't get it to do the noise on another not so steep tilt while parked. The noise does not occur while turning with the engine off. I've tried that a few times our here in the middle of nowhere. Now the plenum started leaking coolant...what's next? P1887 returned eventually. I'll mention that to the transmission shop, but I doubt they'll cover the switch although they could have caused a bad connector. They did replace the torque converter.

I've just been driving the car with the noise although still have not found a nice tilted lot again. I drove to the dealer last week and they had cars parked all along where I had driven/parked before. I do think the noise is ever so slightly worse. The coolant leak is also getting slightly worse and I'll tackle that project after the holidays. It mostly seals up as soon as the engine is hot. Merry Christmas and happy new year!

Happy new year!
I finally got a chance to get a video on a tilt with the noise while parked usually only heard when turning right.
Original video: https://share.icloud.com/photos/07a51tA ... kFPonjUipw
Noise while parked video 1: https://share.icloud.com/photos/05dzUmW ... c0YuCsMSug
Noise parked video 2: https://share.icloud.com/photos/099Jnaf ... zoKS9smkyw
Noise from inside/outside while parked: https://share.icloud.com/photos/086IU0h ... trMB1MhcTg
If it's the starter, I haven't noticed anything usual when starting, but it seems to require that the entire front be shifted left.
I'm still leaning toward the flex plate. The check gauge light is the fuel sensor and the check engine is the TCC switch.

I understand it's not convenient, but parking where it will make the sound and removing the belt to let it idle for a minute can rule out some stuff. Maybe if you have a portable ramp, pile of boards, or maybe even jack the passenger side up. Might also have to remove the starter and inspect the Bendix and try to move it in/out.

J Wikoff wrote:I understand it's not convenient, but parking where it will make the sound and removing the belt to let it idle for a minute can rule out some stuff. Maybe if you have a portable ramp, pile of boards, or maybe even jack the passenger side up. Might also have to remove the starter and inspect the Bendix and try to move it in/out.

Thanks, I'll remove the belt when the temps here are higher. That should rule out the accessories/harmonic balancer. Jacking up in a variety of ways doesn't cause the noise while parked although I haven't yet tried a side ramp or planks. It seems louder on the transmission side. I wasn't planning on doing any diagnosis when I caught the noise on video. The only sure way to make the noise is to drive it and turn or bank right. I think driving for about an hour helps make the noise when all four wheels have weight on a tilt while parked.

That is the SAME noise I am hearing in my 2001 SE!!!