Suspension refresh....new resonance noise @ 1800 RPM.

I completed a front/rear suspension refresh on a 2004 Jetta TDI (250k miles): struts, shocks, ball joints, tie rods, bushings, etc. along with front/rear rotors/pads. All went well.

However, now when I drive, I have a new loud resonance sound just under 2000 RPM. Driving in 5th gear at 55 MPH seems to make the loudest noise. I think I have another resonance point at lower RPM around 35 MPH. I've never heard these previously.

What happened? This sound like exhaust resonance to me. My best guess is that as I was jacking up the car corner by corner, I twisted and body a bit which subsequently twisted the engine/exhaust - maybe shaking loose some carbon, etc.? Maybe a pipe is now touching metal somewhere? Ugh. Uncertain. Can anyone provide direction?

Thanks!

Hey, were you ever able to diagnose this?
I just did a full refresh with koni reds last week and I have the same problem.
I was hoping it was just out of alignment causing the noise but its still there.

Hi

I know this is a really old thread but I just had my suspension refreshed also and I ended up with a low droning type noise also ....

For what it's worth I did go with harder Audi TT bushings VR6 Springs and koni special active shocks which made everything stiffer so I'm guessing that's what's causing the extra drone ??

Hopefully somebody else can chime in on this since it seems to be a fairly standard problem with suspension refreshes although I'm assuming mine maybe a little worse because I used upgraded harder bushings and firmer springs/ dampers..

Thanks
Andrew

Do you have a dieselgeek skid plate or other similar skid plate?

Tdijarhead said:

Do you have a dieselgeek skid plate or other similar skid plate?

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No just factory plastic under body tray and side enclosure
... never made any droning type noises before the suspension refresh ....

Its not intolerable.... just a little annoying....

Silly question, have you had the car aligned?

Yes car aligned ....

Having read a lot of posts about the front end settling down with use I was tempted to wait a little while until the suspension settled before getting a professional alignment but ultimately decided to get the professional alignment done afterwards and worry about it again if the suspension Settles...

I've driven the car approximately 1000 miles since the suspension was redone and it does not seem to be getting any lower so fa
r knock on wood. ...

I'm beginning to think that additional droning is inevitable with the beefier suspension ?

Of course Factory cars that come was heavier Duty suspensions like Audis Etc probably don't suffer from that I would imagine

good lord, 7 posts over 7 years!!!!!
this has to be the slowest thread to date!

Old thread but some resolution.

I did a suspension refresh (springs, struts, all bushings (TT style)) and had the same issues. I replaced the inner CV joints and it got better and went away after some time. My car's ride height changed quite a bit with the new springs and struts (1.5"?) and I believe that the CV's needed to wear into the new range of motion.

If you took the old CV joint and moved it through it's range of motion you could feel as the 'circle' of motion got larger the balls go into and out of a loose area and into a tighter area that the car didn't see when the suspension was worn. ie the driveshaft is straighter from the trans with saggy springs.

It would be interesting to hear from the folks that have lifted their MK4's with beefier springs to see if they saw this as well.

My symptoms were in 5th gear at lower RPM (1500-1800) if I applied throttle the car would pound or thump. On the highway at higher speed and RPM, there was no problem.

Mongler98 said:

good lord, 7 posts over 7 years!!!!!
this has to be the slowest thread to date!

Click to expand...

I've always thought best practice was to search, and if you find an exact match to what you're concerned with, re-use the thread.
Lots of folks see this in the opposite.

I'm new to the TDI world but been wrenching on wheeled vehicles for years. In recent experience with two old >200k miles Honda Elements that I picked up for a song, the suspension was shot on both. On #1; I fixed the most obvious problems - ball joints, damper mounts, sway bar links, etc. to fix the "clunk" only to uncover the other wear items that the obvious problems item were masking. Eventually I ended up replacing just about every piece of rubber in the suspension and solved all the noises. On Element # 2 I ordered almost every piece of rubber from the beginning of the refresh. Also, I didn't go OEM on most of it because I didn't want to spend more on rubber then I did on the car.

zslink in post #9 makes a lot of sense. If it hasn't been done before and you don't want to buy yet more parts, simply swapping the inner CV joints side to side (pretty easy for a manual) would do the same thing.

I don't know about automatics, as the tripodal joints are something I haven't dealt with.

If this swap was done previously, new CV joints would be absolutely required. A swap is done to rectify pits in the driven races of a CV joint. If a swap was done before, then those pits will make the problems worse when you swap and put the pits back into the main driven surface of the races.

Cheers,

PH

Way back when I had a 2002 Jetta, I did the "Mufflerectomy", I.e removed the muffler. After 2 years I could not stand the droning sound and had a straight through muffler installed. That cured the droning!

zslnk said:

Old thread but some resolution.

I did a suspension refresh (springs, struts, all bushings (TT style)) and had the same issues. I replaced the inner CV joints and it got better and went away after some time. My car's ride height changed quite a bit with the new springs and struts (1.5"?) and I believe that the CV's needed to wear into the new range of motion.

If you took the old CV joint and moved it through it's range of motion you could feel as the 'circle' of motion got larger the balls go into and out of a loose area and into a tighter area that the car didn't see when the suspension was worn. ie the driveshaft is straighter from the trans with saggy springs.

It would be interesting to hear from the folks that have lifted their MK4's with beefier springs to see if they saw this as well.

My symptoms were in 5th gear at lower RPM (1500-1800) if I applied throttle the car would pound or thump. On the highway at higher speed and RPM, there was no problem.

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Hi

That's an interesting thought about wearing the joints in it seems to make a lot of sense given that a car had over 320,000 Miles when the suspension was redone . . ..plenty if time to make specific wear areas ....

I may try asking a similar question regarding drone over on the beef on a budget thread.... that was a good idea but one thing I'm wondering is how many of those folks keep the same tires after reaching for the sky suspension wise .... I would think most of those folks upgrade to bigger tires with different tread patterns after raising suspension whereas I kept my same tires after the suspension refresh

I guess I'll try see how things go over time ....

Andyinchville1 said:

Hi

That's an interesting thought about wearing the joints in it seems to make a lot of sense given that a car had over 320,000 Miles when the suspension was redone . . ..plenty if time to make specific wear areas ....

I may try asking a similar question regarding drone over on the beef on a budget thread.... that was a good idea but one thing I'm wondering is how many of those folks keep the same tires after reaching for the sky suspension wise .... I would think most of those folks upgrade to bigger tires with different tread patterns after raising suspension whereas I kept my same tires after the suspension refresh

I guess I'll try see how things go over time ....

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I would guess the opposite. Most people running stock sized tires around here.

CV axles not working properly and droning due to a different ride height?????
NO, not a chance, never.
only way this would happen is they were severely worn down to the point of failure or near failure. Maybe if you have little to no travel, but a worn system would have MORE travel and range of it.
Things that can cause a drone like that are exhaust, unbalanced wheels, failing parts but not suspeniton unless you count squeaking!

Mongler98 said:

CV axles not working properly and droning due to a different ride height?????
NO, not a chance, never.
only way this would happen is they were severely worn down to the point of failure or near failure. Maybe if you have little to no travel, but a worn system would have MORE travel and range of it.
Things that can cause a drone like that are exhaust, unbalanced wheels, failing parts but not suspeniton unless you count squeaking!

Click to expand...

Hi

I'm glad you think that ... i just spent a bunch of $$ on parts / labor that i'd hate to pop for cv joints as well ...

When I was touching up some Rust spots I had to take out the inner fender liner in my car and I noticed spindle assembly had what appeared to be a bunch of hammer marks on them ( I'm guessing the mechanic beat on the spindle to remove front strut?)

Could something be bent or over tightened that caused the droning noise?

I'm not sure the engine or transmission had to be moved to do a front suspension refresh but at idle it does seem to make a little bit of drone .... for what it's worth there was no droning before the suspension refresh so whatever happened while the car was away and getting the suspension refresh is what caused the new Asdroning noise....

For whatever reason I did notice the idle speed seems to be a little on the high side at 950 RPMs not sure why that was or has changed I think it was more like 800 before...

Anyways I'm hoping to get to the bottom of the droning noise but for what it's worth I did get the alignment specs and the numbers seem good ....

I just can't imagine why the upgraded Parts I use would cause a drone because I'm sure Audis and other high-end cars with tight suspensions don't have to deal with droning noises. ..or maybe they have extra sound deadening to make up for the additional nvh of a tighter suspension?

For what it's worth when the weather gets warmer I do plan on adding some sound deadening mats inside the doors and headliner areas...

Get better tires. A siffer suspention will cause whatever the road is touching to translate more into the cabin. You want drone? Try driving on my hot RE71s amazing traction, best you can get for a dot legal,and I'd use that term loosely.
Ballance or just strait up change the tires of there over 5 years old on the dot#

CV axles are 1 of 2 things, good or bad.