Intermittent noise/vibration while under power/decel, seems like CV, but not?

bigred177

Veteran Member
Joined
Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
97 Jetta, 245k miles.

Took the car to have all four wheel bearings replaced, control arms rebuilt, new ball joints, new tie rods, and new shocks front and rear. I don't know the age of the axles or clutch, but the clutch is on its way out.

After finishing the work with no apparent problems I took the car for an alignment and then to Discount Tire for a balance and rotation.

After the rotation, the car was making a metal on metal sounding noise. In the past after a rotation sometimes one of my parking brake cables would come out of its hanger and rub on the rim, making a "click" noise as it bumped the wheel weights on the inside. That's what this sounded like, but wasn't the case this time.

It did it briefly then went away. I drove the car about 4k miles and it seemed okay. Then it started making the noise again faintly, growing louder over the course of about 500 miles to the point that it sounded like the car was going to come apart. It happens driving straight or in a turn, no difference. It would also have an intermittent vibration associated with it that was only present under power, like something is out of balance but it won't do it while coasting. The vibrations will get pretty violent before calming down and going away for a while.

The noise and vibrations will go away for some time and then come back. It sounds like it's coming from the center of the car. I thought it was an inner CV, but the mechanic said they look good. He also "drove" the car on the lift and couldn't get it to make the noise.

Over time the noise will go from faint, to making the noise under accel, to making the noise on accel and decel, then making he noise even while in neutral coasting. Then it'll stop for 100 miles.

I'm at a loss.
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
I'd be checking the wheel bearing on every corner regardless of whether they're recently replaced or not.

I'd also be talking to the tire shop to make sure that the tires don't show any irregularities during the balancing...sometimes shops won't tell you.

Also, are you running any aftermarket wheels that have a different fitment then factory?

Steve
 

bigred177

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Joined
Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
While up on the lift we checked the wheel play to see if it was a bearing.

I will take it back and see what they say but I can't see this being wheel related since it's so hit or miss. When it's not acting up the car feels amazing.

They are aftermarket wheels but they have been on the car since I've owned it for about 60k miles. They have hub adapters(?) plastic rings to make the wheels sit center. They're all present.
 

Mongler98

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Joined
Mar 23, 2011
Location
COLORADO (SE of Denver)
TDI
98 Jetta TDI AHU 1.9L (944 TDI swap in progress) I moved so now i got nothing but an AHU in a garage on a pallet.
if its not humming all the time when going around the right or left corner, its not the bearing. Besides even fairly noisy bearings cant be felt with the tire on when on the lift. you can feel it a little bit when the wheel and rotor are off and feeling the hub directly.
 

rallywagon

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Sep 19, 2007
Location
Western NC
TDI
'98 Jetta, '00 Jetta
I replaced my control arms on my '98 with some cheapos (Prime Choice)...seemed OK in every way, but they had a slightly thicker/taller flange that makes contact with my sway bar on one side or the other....it can sound like what you are describing. Try sliding a pocket knife between your sway bars and your control arms on both sides. Sometimes I get a rattle/squeak from the contact....other times I hear a growl under medium acceleration.
 

bigred177

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Joined
Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
I will check, but I'm 99% certain this is related to something rotating in the driveline. I can't adequately describe all of the things it's doing. Anyone in Houston want to go for a drive?

What kinds of issues does the differential have in these transmissions? The noise and vibrations sound like they're coming from the centerline of the car. There is fluid in it and the gears shift fine. It's just such a strange feeling.
 

Abacus

That helpful B4 guy
Joined
Nov 10, 2007
Location
Relocated from Maine to Dewey, AZ
TDI
Only the B4V left
Check your motor/tranny mounts. I've had the engine shift and create contacts and then return to normal at random times. The A3 had a factory hydraulic tranny mount that would fail in time. I have quite a few pictures of them failing but still looking ok from the top.

An easy check is to put the car in reverse, with the hood open and one foot on the brake (or parking brake on), and lightly load the engine by letting out the clutch. If the mounts are shot, the engine will lift from the rear. I had one car on which the owner said it'd make a huge bang sound in reverse if he wasn't easy and he thought the tranny was bad. It was the entire engine rotating forward and slamming into the fan assembly due to both rear mounts being torn apart. And yes, the exhaust flex pipe needed replacing as well due to the damage.
 

iluvmydiesels

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Joined
Nov 21, 2015
Location
phila area
TDI
AHU
might i point out; the problem seems to have started when you took your car to a cheapie tire place, for a balance and rotation. somewhere right there a problem seems to have happened. for one balance, could be weight(s) in few miles have fallen off. another-2, you have off-center aftermarket rims, and plastic hub rings. rims may not have been put back on right. plastic may have been cracked or put on wrong and have serious problems there. causing rims to ?rub? and/or ruined plastic rings, causing that and vibration.
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
I would ask the tire shop if there were any odd wear patterns on the tires. I've had tires balance out before but when I went for a ride they made a rumbling noise on the pavement because they had weird wear pattern across the tread surface.

The shop never said a thing because they didn't probably check for that, and it wasn't their job to do so. They were hired to balance and that they did.

Changed tires and problem solved.

I would also ask the shop if they made sure to reinstall the hub rings with the wheels like iluvmydiesel suggested.

I'm not criticizing Discount Tire, I think they do a fine job, probably better than some places and any more the tire mounting/balancing technology really takes care of any employee idiocy. The one benefit is that all they do is sell / mount / balance tires so they do have a degree of specialization.

Another question is whether you have directional tires and whether the shop mounted them back on the car correctly?

Steve
 

ToddA1

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Joined
Aug 3, 2011
Location
NJ 08002
TDI
'96 B4V, '97 B4 (sold), '97 Jetta (scrapped)
The intermittent part has me wondering, but try applying more torque to the outer CV nuts.

-Todd
 

iluvmydiesels

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Joined
Nov 21, 2015
Location
phila area
TDI
AHU
at one time, yrs ago, i had a shop put in axles, after some years of running around, seems inners had loosened some, thats what you get for book tightening values, hence now i get inners to about 42ftlbs or so. nice and snug. mine made quite an obvious noise mainly during acceleration. inners/outters easy to check and if problem to correct. i like to hit outters w/a good impact, if they do need tightening finish with a bar & pipe.
 

bigred177

Veteran Member
Joined
Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
Sorry for the super long delay. Thought we had it worked out,
but then not, and I took a break for a bit.

Check your motor/tranny mounts. I've had the engine shift and create contacts and then return to normal at random times. The A3 had a factory hydraulic tranny mount that would fail in time. I have quite a few pictures of them failing but still looking ok from the top.

An easy check is to put the car in reverse, with the hood open and one foot on the brake (or parking brake on), and lightly load the engine by letting out the clutch. If the mounts are shot, the engine will lift from the rear. I had one car on which the owner said it'd make a huge bang sound in reverse if he wasn't easy and he thought the tranny was bad. It was the entire engine rotating forward and slamming into the fan assembly due to both rear mounts being torn apart. And yes, the exhaust flex pipe needed replacing as well due to the damage.
I knew I needed to do this anyway so this was my most recent fix. So far the car hasn't made the noises but I haven't driven it much since then. Driving to Houston tomorrow will be the test that usually makes it act up. Man, there is a noticeable difference in vibrations at idle between new and very old mounts. The previous owner had put the Passat solid mount in evidently, went back to the hydraulic.

might i point out; the problem seems to have started when you took your car to a cheapie tire place, for a balance and rotation. somewhere right there a problem seems to have happened. for one balance, could be weight(s) in few miles have fallen off. another-2, you have off-center aftermarket rims, and plastic hub rings. rims may not have been put back on right. plastic may have been cracked or put on wrong and have serious problems there. causing rims to ?rub? and/or ruined plastic rings, causing that and vibration.
I have experienced all of these before because of these wheels on this car. So now I watch them like a hawk when they do my tires and I also let them know about the spacer rings. I know all of the things you describe well, and what the car is doing now isn't any of them.

I would ask the tire shop if there were any odd wear patterns on the tires. I've had tires balance out before but when I went for a ride they made a rumbling noise on the pavement because they had weird wear pattern across the tread surface.

The shop never said a thing because they didn't probably check for that, and it wasn't their job to do so. They were hired to balance and that they did.

Changed tires and problem solved.

I would also ask the shop if they made sure to reinstall the hub rings with the wheels like iluvmydiesel suggested.

I'm not criticizing Discount Tire, I think they do a fine job, probably better than some places and any more the tire mounting/balancing technology really takes care of any employee idiocy. The one benefit is that all they do is sell / mount / balance tires so they do have a degree of specialization.

Another question is whether you have directional tires and whether the shop mounted them back on the car correctly?

Steve
Same as above. No strange wear on the tires and not directional.

The intermittent part has me wondering, but try applying more torque to the outer CV nuts.

-Todd
That was the initial suspicion about 3 weeks ago. Loosened them and them hammered them back down. They are not loose now. Car was fine for about 120 of 180 miles from Austin to Houston and then it started making the noises again. Then, when driving locally, it wouldn't. On the way back from Houston to Austin it started about 80 miles into the trip. The vibrations got so bad I wasn't even able to maintain speed for a while. Almost like a death wobble on a Dodge. Anytime I added power to maintain 60 it would shake terribly. Then it stopped.

at one time, yrs ago, i had a shop put in axles, after some years of running around, seems inners had loosened some, thats what you get for book tightening values, hence now i get inners to about 42ftlbs or so. nice and snug. mine made quite an obvious noise mainly during acceleration. inners/outters easy to check and if problem to correct. i like to hit outters w/a good impact, if they do need tightening finish with a bar & pipe.
That's the next thing I'm going to mess with if the motor mounts didn't get it. I grabbed the axles with both hands and shook with all of my 250lbs and they didn't make a peep.


Before removing the mounts I put the car on stands and ran it in gear. With no load on the drive line nothing happens, but when I started adding load by stepping on the brake and applying a little power the engine started bouncing quite a lot. Never made the noises but the bounce felt the same. I watched from the outside while another driver did the same thing and the passenger rear motor mount looked like it was providing no resistance to the movements.


Fingers crossed, we'll find out tomorrow.
 

bigred177

Veteran Member
Joined
Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
Anyone have a good source for those plastic clips that hold the hood insulation up? My last two let go today and it fell down. Car seems louder now and I wanted to stick it back in.
 

bigred177

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Joined
Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
Well that didn't do it. The motor mount controlled the vibrations a little more but it's still often and violent.

Someone I talked to threw out ball joints as a thought. I can't really think of a reason why they would cause a problem but they were one of the things replaced right before this started happening. Maybe?
 

iluvmydiesels

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Joined
Nov 21, 2015
Location
phila area
TDI
AHU
ball joints arent really a load or power area where it would shake violently. if you jack up a tire, either push/pull on bottom of tire, or take a engine pry bar and try to pry tire out, and see if it has play. mostly this will tell you if a ball joint is bad. seems what your describing is in the power 'train' it mostly stops at the cv/axle ends, and may include the wheel hubs, and perhaps wheel bearings.
id get underneath, put on stands and check all nuts/bolts,fasteners for tightness, for one, with up on stands and someone in drivers seat, check inner cv bolts are well snug. check brakes, calipers are good and tight too..other than that thats all the help i can be for now. gl.
 

bigred177

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Joined
Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
Is there any way to peek into the transmission/differential to check its health? Could something in there be causing the problems?

My clutch Master was not holding pressure so I thought maybe it was causing some interference with something. Changed it out and now it feels much better, and safer, but no change on the original problem.

Putting the car on stands and in gear there is a little play rotating the wheels back and forth along with some noise from the transmission/differential. No slop at all in either axle. I have a new passenger axle, but don't want to mess with that unless I have to.
 

bigred177

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Location
Austin, TX
TDI
97 Jetta
The transmission has always had a good fluid level in it and it's never been hard to shift in any gear and it stays in gear.
 

bigred177

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Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
I had pulled it up onto ramps the other day and when I drove it afterwards it still made the noise. I just had it up on jack stands off of the wheels and now it's not making any noise at all. It's done this a few times. Maybe a clue?
 

bigred177

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Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
Put a passenger axle on just because we had it already and we're running out of spinning parts to put on. We'll find out tomorrow.
 

iluvmydiesels

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phila area
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i dont know what exactly to tell you from here. i doubt its transmission, although if the fluid level is low, well you ll eat 'er up, if its that bad, and if its trans, it d be pretty well gone by now. i forget exactly how to check that trans level. on a level ground, perhaps, pop off fill up screw, and see if fluid dribbles/drains out. not 100% sure of fluid level. as for mk2s youd fill from fill up, as fluid tops off and some dribbles out, you not put cap/screw on, and add a 1/2 (oz?iirc) in top speedo port.
possible, yet remote, it could be clutch related. just running down diagnosis line. either or both axles, or cv joint tightness. wheel bearings, or hubs, could be the wheel bearing hub assembly. ball joints not as likely, tie rod ends not as likely. if either its most likely not mounted correctly, could be defective parts. if either most likely not tightened enough/correctly. it could be bad a-arm(s), mainly shot bushings in a-arm.
gl in tracing down. other than that when that shop dismounted tires, its possible something happened with those wheel rings you use. or some type of balancing problem. that has been previously discussed. or something went wrong/is incorrect in the alignment you got. :confused:<scratch head.
 

bigred177

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Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
Well after about 200 miles it seems to be holding together. First trip I've made since September where my fillings are still in my head at the end of it. There wasn't any obvious damage to the old axle/cv, it actually looked like it was in really good shape. The condition combined with the fact that the worst problems occurred straight ahead and not in a turn seems like a really strange failure. I'll just be glad to have it fixed.
 

Steve Addy

Top Post Dawg
Joined
Aug 7, 2002
Location
Iowa
TDI
97 Mk3
Did you replace the CV's along with the new axle? I'd be curious to know since that's three different parts that could be at fault.

Would also like to know if the axle that was one there originally (prior to your replacement) was a hollow axle or a solid one? Some aftermarket replacements are solid and those are known to cause problems with vibrations.

If the axle shaft itself is in good shape, not bent at all, and it's original I encourage people to replace the CV joints and boots alone and use the good axle.

Steve
 

bigred177

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Aug 23, 2011
Location
Austin, TX
TDI
97 Jetta
I replaced the whole assembly: axle and both CVs. I'm thinking it was something to do with the inner CV because the noise was mostly there. I don't know if it's hollow or solid but the new axle is quite a bit thinner than the one it replaces. The old one wasn't original. Interpart I believe. I'll have to look at it. I'm not near it right now. I was thinking about rebuilding the CV and having it as a spare. Everything looks like it's in great shape.

What's weird is that everything was fine for the last 60k miles and then all of a sudden it wasn't, but no obvious failure.
 

iluvmydiesels

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phila area
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AHU
passenger axle is best large 'tube' type of (longer side) axle. thinner may be a different aftermarket, or somewhat cheaper (again aftermarket). you want this side axle to be hollow (kind of like tubular)axle. the factory or oem will most likely still have a dampener about the middle of axle. i have had a few or more (from my NAPA store) that are with-out this dampener 'ring' or doughnut. they tend to run fine, although are quite a bit less expensive from VW factory or similar type,quality axles. a thin(not unlike the drivers-side axle thickness,diameter,or solid) may give problems. got a pic of both axles? would help us to understand what you have in/under there a 'little' better.
if you can get pics, also would help, some, a pic of axle you took out.
 
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