: Diagnosing low rpm vibration and front suspension creeking...



cky3396
04-14-10, 01:46 PM
Hey all,

I am experiencing some creeking in the front suspension (seems like drivers side only) and also some vibration / noise at low speed and low rpm. At times, the front suspension creeking is hard to replicate - but when you I can get it to make noise its obvious something is going on. The vibration from the low speed / low rpm mix is easily repeatable. At any rate, here's the info:

Front end creeking - From a stop, light acceleration will produce the creeking sound. I also get the sound when braking, just before coming to a full stop (low speeds). It's more difficult to produce the sound when I take off or stop more quickly. Going over some bumps at low speeds also produced similar sounding creeks from the front end, but not all bumps. I put the car up on ramps and gave the sway bar a tug, check the end links - I had a car make similar sounds in the past, due to loose sway bar connection. But it seems solid.

The engine vibration / noise I hear is easily produced. From a complete stop, letting the clutch out slowly and giving just a little gas, there is a distinct vibration and noise from the front end until the speed and RPM picks up. It is especially noticeable when shifting from first to fourth gear, at low speeds. If however, I give more gas starting from first gear and keep the RPM from dipping too low the vibration does not occur. Being in too high a gear seems to produce the sound easily. Someone mentioned lugging, and it is a common sound but I had my dealer's shop Forman take a look and he agreed it is not normal. He thought it could possibly be the exhaust vibrating against something, but it wasn't the case.

Searches for front end creeking/thunking bring up motor mounts, sway bar bushings, control arm bushings, and bad shocks. Its hard to find anything on the vibration. I'm just looking for a decent starting point and list of possible culprits when I bring it in for the work.

stixx
04-14-10, 01:56 PM
Unfortunately I have nothing to offer except to state that what you describe with your "vibration" is EXACTLY what I am experiencing; started about 2 weeks ago. Taking my car in to the dealership tomorrow for some routine maintenance and having them look at this as well.

814V
04-14-10, 04:20 PM
My car also does the suspension creek but only when its cold outside. During the winter months when I leave my work in the evening I go over a few speed bumps and its very noticable. The funny thing is when the car warms up it goes away. Ive been to the dealer to try and replicate the noise but I can never get it to do it in front of them.

Vet+BB=V
04-14-10, 08:24 PM
As far as the creaking. I experienced almost the exact same situation when I first bought my V. I thought it was from the suspension as well. Turned out to be blown motor mounts. Is there a heavy thud in the front end when shifting from 1-2 during hard acceleration? (motor mount) You can also have someone load the engine in gear with the parking brake on in 1st and reverse while watching the motor to see if there is a large amount of rocking from side to side, again motor mounts. Just a couple of thoughts.

Vet+BB=V
04-14-10, 08:25 PM
I meant to say vibration, not creaking, sorry.

cky3396
04-15-10, 03:59 PM
thanks for the responses.. no thud between shifts for me. i'll definitely suggest that the motor mounts get a look. im sure the techs will get to the bottom of it all.

stixx
04-15-10, 06:08 PM
Just heard back from my dealership and it's MOTOR MOUNTS FOR THE WIN! This is what was causing the "vibration" described above; at least in my case. Hopefully this helps.

cky3396
04-15-10, 10:45 PM
good to know, thanks for the update! i go in monday, we shall see!

cky3396
04-15-10, 10:50 PM
PS, how exactly did the dealership determine this? motor mounts visibly shot, leaking, or..? the shop forman at my dealership thought it may be exhaust vibrating at first. i couldnt leave the car with them to give it a better look.

Vroom-Vroom!
04-16-10, 02:49 AM
As far as the creaking. I experienced almost the exact same situation when I first bought my V. I thought it was from the suspension as well. Turned out to be blown motor mounts. Is there a heavy thud in the front end when shifting from 1-2 during hard acceleration? (motor mount) You can also have someone load the engine in gear with the parking brake on in 1st and reverse while watching the motor to see if there is a large amount of rocking from side to side, again motor mounts. Just a couple of thoughts.

Dude I have that thud during hard acceleration and ONLY when shifting 1-2. So you're saying it's the motor mounts? Or could be something else?

stixx
04-16-10, 04:17 PM
Typical - apparently the motor mounts are on back-order. Would love to put some aftermarket mounts on, but the dealership certainly wont do that under warranty. Oh well - the wait begins.

rjoffe
04-16-10, 05:08 PM
Actually, ask them !

Vet+BB=V
04-16-10, 08:50 PM
Dude I have that thud during hard acceleration and ONLY when shifting 1-2. So you're saying it's the motor mounts? Or could be something else?

Yes I think it could definitely could be motor mounts. I have seen this before at work on other models and it was exactly what my car was doing. (both of my motor mounts were leaking, and the upper portion of the mounts were totally separated) There is a short period of time between shifts where the driveline torque load is minimized allowing the motor to "fall" down on the left side and when second is engaged (assuming you maintain traction) that load will lift the motor right back up. The thud is the motor dropping down on its mount right when the clutch is disengaged. Like i mentioned above you can try and check them from the top by doing a stationary load test. Even if you're not sure how far a motor should move (not much) you will notice it jumping around like a wild bull with bad mounts.
Hope this is helpful.

stixx
04-16-10, 09:13 PM
I tell you what, my dealership (Heritage Cadillac) has really been dropping the ball lately. Went to go pick up my car (sans motor mounts) and I notice that my throttle is somehow stuck at 2000 rpms. It was like a mini Toyota deal. How their techs do not road test a car before closing it out is beyond me. Their techs were already gone for the evening so now I am stuck with a lousy SUV. argh

Vroom-Vroom!
04-18-10, 04:08 AM
Yes I think it could definitely could be motor mounts. I have seen this before at work on other models and it was exactly what my car was doing. (both of my motor mounts were leaking, and the upper portion of the mounts were totally separated) There is a short period of time between shifts where the driveline torque load is minimized allowing the motor to "fall" down on the left side and when second is engaged (assuming you maintain traction) that load will lift the motor right back up. The thud is the motor dropping down on its mount right when the clutch is disengaged. Like i mentioned above you can try and check them from the top by doing a stationary load test. Even if you're not sure how far a motor should move (not much) you will notice it jumping around like a wild bull with bad mounts.
Hope this is helpful.

Thanks, I'll look into it this week. Kinda hope it's the suspension though haha cause if it is, time to lower my ride

cky3396
04-19-10, 07:41 PM
turns out both motor mounts are shot. on back order! well, at least the issue has been diagnosed. just waiting for that call and they will swap em out! gmpp!

stixx
04-23-10, 02:19 PM
Just got my motor mounts installed yesterday (yes, they are back in stock). I was amazed what a difference they made. Probably the biggest thing is how much easier and "refined" shifting appears to be. Good stuff.

calicadi
04-24-10, 03:49 PM
Creeking in my '04 went away when I replaced the stock sway bars with the Hotchkis models that come with zirks on the bushing mounts. I use marine-grade grease to lubricate them for its water resistance. When I rotate the tires, I hit the zirks to keep the grease fresh. Immediately after installing the Ground Control kit, I did get random suspension noise on occasion. Using a spray white lithium lube on the friction areas took care of that.

cky3396
05-12-10, 05:18 PM
new mounts finally came in today, so the V is in the shop. we'll see how it turns out! hopefully all of the issues are taken care of, but i have a feeling the vibration and front suspension creaking are unrelated.

stixx
05-12-10, 06:02 PM
If you need details what my dealer did to resolve the same issues, PM me.

cky3396
05-12-10, 11:51 PM
thanks, im told by my service advisor that everything sounds good and its ready to go. he also says the old mounts were torn up, and completely busted.

i pick her up tomorrow AM.

cky3396
05-14-10, 01:03 PM
update: new mounts in, completely different car. new road feel, new shift feel, new idle, new everything. if i describe it in one word, refined. the new mounts fixed all issues including the "suspension" creaking, and then some.

the old mounts were in bad shape. my guess is that they are the original mounts, and the car currently has 45000 miles