CaliSaysRelax

SMALL UPDATE ^^^ VIDEO OF SOUND I HEAR DRIVING DOWN THE ROAD


Hello MBWorld members,

First post here and hopefully a good one. so here we go.

I have an 06 c230. just over 105,000 miles on it. also is a 6 speed.

So heres the problem.

about a month after getting the car I noticed a chirping sound which sounded like it was coming from up front near the belt so i figured it was a belt problem. it made the chirp sound at idle briefly and then it stopped. didnt hear it for a week or so. next time I hear it and it sounds like its coming from the driver side wheel well. When I brake the chirp goes away. I mean anytime i step on the brake the sound goes away. about two weeks later it sounds like its now coming from both the driver and passenger side wheel well. I take the tire off. check to see how the brakes look. check the wheel bearings to see if there is any play in it and there isnt. the brake pads look great. the rotors feel smooth. dont know if i should think that the rotor is warped in any way and its rubbing on the pads. but again everything seems to check out.

Heres the curveball that threw me off completely a couple of days ago.... I pull up to the stop light and im sitting there, at a dead stop and i begin to hear the chirping again. this confuses me because usually the braking is what made the chirping go away and now it happened when i wasnt moving. its not conditonal with the weather or whether the road is smooth or bumpy really. not any better or worse if im turning a certain direction.

so theres my problem.

1)unknown chirp
2)braking makes it go away(until recently)
3)not conditional with weather
4)brakes seem fine



any input would be helpful.

I didnt see any other threads posted about this same problem so i apologize if i missed it and i created this thread for no reason.

Thanks again for any potential input on the problem.

Glyn M Ruck

Are you quite sure that it is not the HVAC fan chirping? They often do.

CaliSaysRelax

someone suggested that to me before but from what theyre describing, it sounds a little different from what im hearing. would braking stop the HVAC fan from chirping though?

Glyn M Ruck

The car slowing down could stop the chirp if it's the HVAC fan. Less air blowing into it. Turn up the fan speed the next time it does it and see if it disappears.

Moviela

Aftermarket front rotors? Zimmermann perhaps? I would indicate the rotors for lateral runout after I fiddled with the fan speed. Chirp could be the rotor kissing the pad once around, and this would go away with the brake applied.

CaliSaysRelax

ok thanks I'll give that a shot. I do have an update on the situation though. I started it last night and while idling it began to make the sound. Popped the hood and sounds like its coming from the belt. I don't know if its just creating Ann echo by the belt or if it is actually a belt or pulley problem. ButI'll check the HVAC fan also.

After what happened last night at idle I'm sure the problem isn't involved with the brakes or rotos.but up until last night that could have been a possibility.

Thanks for the replies. Really appreciate it. Keep em coming if you have any ideas.

Glyn M Ruck

Take off the Poly V belt & check idlers, tensioner & all auxilliaries that the belt drives. Idler/tensioner squeel is fairly common. Replacement fixes.

Also check that anti rattle clips are properly installed on front brakes/pads.

ncmudbug

Does the '06 C230 have a sprag bearing like the '05 (or is that what you were referring to when you mentioned HVAC fan chirping)? I don't like those things!

nizzle

How do you check the idlers?

CaliSaysRelax

oh ya.....


BUMP

jkowtko

You haven't stated whether the sound changes with engine speed and/or vehicle speed. If you would like to try the following:

First, turn off the HVAC completely.

Then, drive at a slow speed and try to different gears so engine speed changes significantly. Try going 15-20 mph in first gear, then second, then third if you can at the same speed.

Try gears 3-5 at a higher speed ... 30-40 mph.

Try 4-5 at 65 mph.

That should tell us immediately if it's an engine accessory/belt noise or in the suspension/drivetrain/body.

If you think engine accessory related, try these while driving at a slow constant speed in the same gear:
* AC max on vs off? (AC compressor)
* turning steering wheel back and forth vs holding it steady (PS pump)
* turning on and off headlights (alternator)

If you think it's suspension related, try:
* driving backwards vs forwards
* uphill vs downhill vs level ground
* turning (sideways force) vs straight.

I also noticed a ticking sound in addition to the chirp. Is that a problem too? Does that follow the behavior of the chirp or have different symptoms?

sammydragon3

a ticking noise can be a variety of things...stepper motors failing , purve valve, lifters which isnt a problem

and ya turn off the havc system completely off

but if u dont have experience working on cars then u should probally have someone replace the aux belt as maintenance and check (as in spin the pulleys) as glen stated before

CaliSaysRelax

Thanks for the great info.

I have yet to turn off the HVAC completely.

BUT I have noticed a few things that you said I should try.

1) I can say the AC on or off does not effect it. I've tried AC on to the max and off obviously with everyday driving.

2) I did notice at one point when i was testing a few things that it would tend to squeak much more when I was turning the steering wheel left. going right would still squeak slightly but much much less.

3) headlights not an issue.

4) driving backwards not an issue

5) I tend to notice it more when im on a windy road headed towards my girls house which has a few ups and downs but nothing major at all. driving on level roads as well brings the chirping back.

The ticking sound isnt something i even noticed until the video but thats not an issue i cant honestly say ive ever noticed that sound.

jkowtko

Try this when you can. Possibility that the AC compressor is putting a load on the accessory belt.

Okay, this brings up a few questions/possibilities:

* Try turning in a circle but holding the wheel still for a few seconds. Does the sound increase only when you move the steering wheel? (i.e. put a load on the PS hydraulic system) Or it is loud whenever you are in a turn regardless of whether you are moving the steering wheel or not?

* Can you downshift while you are in a turn (keeping the wheel still) to see if the noise changes? And it would still be good to know in general if the noise changes with engine speed or not.

* Is your steering effort hard in general? When is the last time you had the PS fluid replaced? Can you open up the PS fluid reservoir and suck out a tiny bit of fluid with a clear straw or plastic tubing, to look at the color. Is it light translucent green, light amber, or dark brown? Or some other color? In these cars old or incorrect PS fluid can significantly affect the steering effort and load on the PS pump. Light green is new and correct fluid, amber/brown is old, the darker the older.

Thanks. John