jax_basketball

when my engine is rebuilt i fixed all the stuff new the engine block,cylinder head etc.first few days there when engine started there was sound of the head tappet. after some day the engine starts to viberates only in rpm 2.i changed the engine mounting,coil,injector,even new plug.the whole body of the car vibrates at rpm 2! but no single misfire in the engine. can someone help me please bugging every 1!

trombone

Did you check all the pulleys under the belt, especially the harmonic balancer?

If at the rebuild the balancer was not properly put back in its place, it can shake the car real bad.

trombone

BTW, 2K rpm is a typical range for vibration caused by faulty engine mounts and/or transmission mount.

A good place to start the troubleshooting

MB-Dude

Replacing the two engine mounts and trans mount will make the symptoms go away for awhile, but will not eliminate the problem. I am still plagued with RPM vibration at ~2.3K and I replaced all 3 mounts 8 months ago. For my situation, e vibration is very prevalent when the engine is cold; less when the engine is at temp. I, too, have no misfire but acceleration - especially throttle response - is not what I would expect. No CEL, either. Get the engine speed up to 3K and vibration tapers off.

I suspect a problem in the variable valve timing. This would account for vibration at ~2.3K, without misfiring, but smooth idle. Anyone who has any theory info on the variable valve timing for the M113, please chime in. JAX and I could use the assist!

Cheers,
Jeff

svetlio_blck

Hi all,

I have the same problem with my 2001 S500L... Had vibrations comming at around 60mph and the car was shaking pretty violent. Changed the transmission mount and everything seemed fine for another 3 days. The mount was actually not bad, but the part was replaced with another number. No there are no violent vibrations, but at 2k-2.3k I get some vibrations. The same can be felt harder on a kickdown for the first second after the kickdown and then disapears...

I will take the car to our official Mercedes dealer to diagnose the issue this monday and will keep you posted.

Best Regards,
Svetlio

Quadcammer

Jeff,
to the best of my knowledge, the M113 does not use variable valve timing.

The only thing variable I'm aware of is the runner length in the intake, but that should not cause a vibration.

tusabes

Everything mentioned above should be Checked - engine and trans mounts , flex disc , harmonic balancers

MB-Dude

Oliver - Thanks for the input. My Star DAS has troubleshooting/verification code for variable valve timing listed for my VIN (2005 S55). In fairness, I have not had time to delve into it. But that's why I am suspicious of 'variable valve timing'. Also, years ago, I had a variable valve timing problem on my '96 SL600. After repairs, the engine smoothed out considerably and performance greatly improved. Sort of similar issue here, just with vibration.

tusabes - The vibration is definitely related to engine RPM, not ground speed. The vibration occurs in any transmission gear when RPM reaches ~2300. So the problem has to be from the planetaries (more or less) forward. That would eliminate the flex disks. I did inquire at the local MB dealer about what I perceived as a slight (and I mean very slight) 'wobble' of the harmonic balancer. The Service Manager looked at it and was not concerned. Now there was a Harmonic balancer issue from the factory, but it was resolved years before my S55 was built. As for the mounts, I could change them again, and the symptom will go away for about 9 months or so. In our case, mounts are not the root problem.

Svetlio - Your vibration is, in all likelihood, a flex disc, because your vibration is correlated to ground speed (60 MPH). With JAX and I, we get vibration at different ground speeds whenever the engine RPM is ~2300.

All - I've been looking into this problem for over a year, as I thought at first my situation was just mounts. However, I am on my second set of mounts and the vibration is once again getting worse. For me, cruising speed is (unfortunately) ~2300 RPM, which means the mounts just get beat to death continually. Hence, the less-than-a-year life span. I have seen this same vibration problem on another W220 on a used car lot. Identical problem; vibration ~2300 RPM that shakes the whole car. That observation suggests the problem is more wide-spread than just a single failure event.

Any and all thoughts greatly appreciated. Thanks JAX for starting the discussion.

Cheers,
Jeff

MB-Dude

OK, Oliver... You got me thinking. A basic Internet search for "Mercedes" "M113 ML55" "Technical Specs" produces nothing of sustenance except for this...
...and while the narration is in German, the cam gearing is assembled starting at the 3:10 mark. While it only shows the left bank, clearly there does not appear to be any variable valve timing, at least as I know VVT. There could be something on the right bank, but doubtful. This is the same engine that is causing me problems. And the engine designation of M113 ML55 refers to the supercharged version of the 5.4 L M113 E55 naturally-aspirated power plant, not an ML-model.

Assuming there is no VVT on the right bank, I'll lean heavily to the harmonic balancer, regardless of what the MB Service Manager said. Oh, and I have run the engine without the s/c belt; no change in symptoms. Thus eliminating the s/c.

Cheers,
Jeff

tusabes

Well there's one way to change your cruising rpm to something different than 2300 Rpm- downshift . Simplest way to avoid the problem

svetlio_blck

Thanks Jeff,
I checked the flex disc thats connecting the propeller shaft with the transmission. There are all together 6 bolts - 3 holding from proppeler to flex disc, and 3 holding from transmission to flex disc. I noticed that one of these from flex to transmission was missing. This way, when I push on the gas pedal, you get an excentric force at the flex disc. The disc was without any cracks - looking almost new. I asume that it was once changed and therefore they didn't fully tightened one of the bolts. After putting up a brand new bolt there and tightening it the cra is running very smoothly and absolutely no vibrations at any speed or rpm can be felt.

BR,
Svetlio