John, that's some great advice, I guess I should switch to illogical thinking, but the noise is just too mechanical and always the same.

I have been driving like this for half a year and as much as I tried to change the variables that I assumed would come into play, nothing made a difference, so you could be right in a way, but I serioulsy doubt it would be related to wind or road surface.

I was thinking about driving without the rear calipers on, just attach them to a spring so they don't bounce around, but to be honest, I'm a bit scared to do that and reach a speed where the thump is most noticable.

Right now I got the e-brake shoes and lines off on the rear, so if I did that, it would leave very little to even look at for problems.

As for where it comes form, I'm quite sure it's the rear since my engines makes a whiney noise and it is clearly heard from the front. I do agree that noise travels in a car, which is probably the reason I have not solved this yet.

Tomorrow I will be doing the second bushing on the spring link, I will see if that yields anything, those had to be changed anyway. Perhaps wear in some part cause the suspension or somethings else to move to a position that would cause something like this to happen.

xp

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1985 190E 2.3L - a constant project.

XP:

A bad axle half-shaft will do that, too, very annoying. I think I read that you have replaced one already, you may want to replace the other.

You are soon going to have a new car there, bud!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

psfred, both shafts already replaced

xp

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1985 190E 2.3L - a constant project.

Sorry, bad math. I thought I was on to something, but I forgot to convert RPM to TPS (thumps per second). Dividing the estimated 1000 tire RPM by 60 results in 16TPS, which could be audible as distinct sounds. Going faster would merge them together into a hum and slower would make them more distinct.

I"m not going to go through all the posts again so I'll just ask if you've turned the rotors.

The fuel pump and vent would be too simple of a solution, but easy to test.

on my dad's car, when they reinstalled the tire, they did not install the tire cover correctly and it had play in it. So whenever the wheel turned while driving the cover would make a tick-tick-tick sound in sync with the speed of the car.

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1996 E320
2000 C230 Kompressor
1988 190e 2.3 - 225K miles, owned for 7 years. I cannot say enough good things about this car. Very well built, even at 225 it ran like new.

Hi John, yep, I actually replaced both rotors, and one of the calipers too Fuel pump is very quiet, no difference in the way it has worked since I got the car.

An update for everyone interested though. I have replaced both spring link bushings in the rear. The second one went a lot smoother, I got the job done myself in about four hours. The rear is not rock solid. I also slapped on some new tires all around, as suggested by hassman, the Bridgestone potenzas, very nice tires, I didn't do any driving with them yet since it's too hot down here, and fixing the a/c is still a bit far on my list.

A new problem though. I wanted to get my wheels aligned, but the shop I was at refused to do it since they claimed something is loose in the front. Now I would say yes it's a possibility, I know the steering box is loose, but the front seemed to be fine for the most part, maybe this is something that just surfaced while I was rebuilding the back end. So my question is, what should I replace in the front to get my wheel alignment? A badly needed one as well since both rear wheels have now been tampered with in order to get all the jobs I listed previoulsly done.

Another discovery, when I pulled off the right wheel carrier, the wheel bearing was very noisy compared to the left one, looks like that will be the next project, boy it never ends does it

Anyway, I need to figure out what parts to replace on the front to get the wheels to have 0 play so I can get a full alignment done to spare my new tires from premature wear HELP HELP

I'll do a search on this during the weekend since I'll have good access to the internet and so on

TIA everyone

xp

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1985 190E 2.3L - a constant project.

Jack up the front and and push and pull to see whats loose. Pushing and pulling the wheels at 3 and 9 oclock suggests steering linkage. Look for loose tie rod, center links ends, or loose idler arm bushings. At 12 and 6 olock the wheel bearings are likely loose. Ball joints, control arm bushings, strut mounts are also possibilities.

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Brian Toscano

I got both tie rods, ilder arm repair kit and a drag llink coming in. My tie rods look terrible and any adjustment to them would probably destroy them. Ball joints will probably be next.

The wheels have play at 3 and 9 o'clock, but other then doing a wheel alignment the car keeps a perfect straight line and there was never any steering problems other then for the steering wheel play.

but I guess I'll start there, I know the drag link shows significant wear, and ball joints as well as any other bushings are probably as bad as they were in the back.

Oh well, one more job to make the car behave like new

xp

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1985 190E 2.3L - a constant project.

xp

While you are under there, check your steering damper.

Haasman

__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)

XP,

I just spent about an hour and 10 min reading every post. Wow!!! I am a MB tech at a dealer. The results you got from the dealer do not surprise me.

couple points. Haasman suggested shocks. I know you checked the hardware but did you remove and drive without them? That was a bit unclear,but very important.

Also, you said it makes no difference whether the suspention is loaded or not. When you ran it up on jack stands, did you or did you not hear the noise from inside the car. If you heard it in that case, and the car is obviously not moving, you can rule out all the loose moldings, wheatherstrips etc. etc. If you didnot hear it then, that means it has to be loaded to duplicate or that suspention position is a relative factor. If the noise will only occur with the car on its wheels, What about finding a shop with a dyno that you can drive at 40kmph and actually stand there next to the car and listen. I have a chassis ear. They do work well.

one of your latest posts said you had some noise out of a wheel bearing. If the noise you refer to is heard unloaded, you may be onto something there. A loaded wheel bearing will sound alot worse usually and can produce a thumping type noise.


BTW how far is Toronto from NH. US. I am so curious about this thing I'd almost like to come Diag myself!!!

Scott

one more thing. You said that there is no vibration. sometimes a vibration can be mistaken as a noise. I see this all the time at the shop.

I only bring this up because you mentioned motor mounts. The mounts in that car are oil filled, and when they go, usually the complaint is "rough idle" which is a misinterpetation of the motor sitting on the crossmember and vibrating. But if the mounts are only sagging and not completely collapsed, it can cause a change in the drive line (drive shaft to diff, trans) angles. and that can cause a vibration. Just thought I'd mention it.

good luck

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Scott

Hassman, I will certainly be doing that next week, parts are here, I just have to go pick them up but I'm working right now so I might have to do that tomorrow.

Scott, I appreciate all the feedback and the info on the motormounts and the problem in general.

At the moment, the thumping seems to be almost gone for some reason, I really have to listen in to hear it, but it is still there, however it does not sound like the car is about to fall apart, I just hope it's not one of those tricks that life tends to pull on everyone.

I did have the car up in the air, and nothing was heard from outside, the inside though I didn't check when it was up in the air, I will probably do that next time I have a chance.

I didn't get to drive without the shocks, I guess I really had no reason to, but I did tighten all the hardware. There is a few more things I can try, but for now I think I will leave it.

Driving on the highway to work yesterday I could not hear the thumping over the tires and engine noise, so I'm taking this as a good sign. I remember very clearly that one time when I had to drive on the highway the thumping was extremely loud, this was in cold weather. What I am worried about now is that the noise will come back once the weather cools down, I hope this is not the case, but if it is, I will follow your suggestion and take the shocks off as well as anything else I can and replace the wheel bearings in the back, I have a plan worked out to do this.

As for vibration, I have numerous people, mainly family members who have heard the thump drive around with me and see if they felt any vibrations or could tell me where the noise originates from. No one claimed any vibrations, most of the ones that were there have dissapeared after I replaced the differential and now that I have the new tires the car is very very smooth. It does vibrate a bit when idling at some points, but I would say those are the motor mounts, I had no idea they were oil filled, thanx for the info Scott

I'm not sure how far Toronto is from you, but I know it's a 10-12 hours drive from here to Chicago, I have family there so we drive down there every now and then. Myabe one day I'll get an enthusiast who would be willing to help out with this if it comes back but as long as I can hear it, I will keep on trying to figure something out to get rid of it.

xp

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1985 190E 2.3L - a constant project.

"This thumping noise started during winter shortly after I had my flex discs and support bearing replaced."

The fact that the thumping seems to be dissipating as the weather gets warmer suggests that it is being transmitted through a rubber mount of some type. The cooler the rubber, the stiffer it is, the less it absorbs.

Seeing how it started in the winter and after your support bearing and flex disc replacement, I wonder if whoever did the job, lined up the drive shaft halfs correctly. there should be a double notch on one side and a single on the other. Put the single between the double for correct alignment.

Also, if the diff was replaced or removed, were all the shims reinstalled for the front mount? what about the rear diff to subframe mounts? are they sagging or cracked. (they are rubber as well)

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Scott

Scott, the driveshaft was actually assembled incorrectly, but since that time I must have had it out on the table at least 20 times to make sure everything is fine. The thumping also did not start exactly right after the flex discs and bearing were done, it was about a months time, but I never did rule out the flex discs as the reason for this, however, the rear flex disc was replaced once again, when I swapped my differential. I was lucky enough that the differential came with one, which further showed that the driveshaft has nothing to do with it.

I went as far as rotating the support bearing to see if there is any difference, I assembled the shaft as many times as I had it out, so believe me, I know the notches you are talking about, however the guy who did the flex discs for me did not, he even got the front and the rear flex disc mixed up.

Another thing to keep in mind is that if the drive shaft were out of balance due to wear or incorrect assembly, it would create a lot of vibration. My car rides extremely smooth, I myself can't believe it at times since it's so old, but it does. I was just doing 140kmph on the highway and I can't feel a single vibration at any speed. With the old tires the car would start shaking at 140, but no more.

Also, when I was swapping the differential, I checked all the rubber mounts, I only found one, but it was fine, no cracks.

Maybe now you are starting to see why this problem drives so many people up the wall Scott

But sure enough, the thumping is still there. Heard it yesterday loud and clear when getting off the highway on a ramp, weather a load on one side had something to do with that or not I'm not sure yet, but I'm leaning further and further towards wheel bearings

xp

__________________
1985 190E 2.3L - a constant project.

xp

Whats happening with the car? .... or more specifically the thumping?

Haasman

__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)