E46 330CD "Grumble" from the drivetrain

[RicoOS]

Hi all,

Just wondering if anyone has ever experienced a "grumble" from the drivetrain on an E46 330CD, it only ever happens at high torque in a higher gear, more torque makes it worse. To describe the grumble, I would say that it's like you used to get in some cars when you floored the throttle in a high gear at low RPM. It's like a grumblely vibration through the entire car, which appears to my ears to come from the front half of the car somewhere. It makes me shy away from full throttle in higher gears, which given that I've got a nice remap (which is limited to 425 lb ft). I would also note that the car did it somewhat before the remap, so clearly the remap has mrerely aggravated it, so it seems to be torque related. I would also note that it's worse the higher the gear.

Now to give some info about all the things that have been changed that it seems therefore unlikely to be and all parts are new, not second hand.
1.) Engine mounts
2.) Gearbox mounts
3.) Propshaft centre bearing/mount
4.) "Doughnut" that connects the gearbox to the propshaft.
5.) DMF and clutch new

Has anyone ever come across this type of noise/fault and if so, did you manage to find out what was causing it?

[d_a_n1979]

When was the last time the diff was serviced?

[RicoOS]

d_a_n1979 said:

When was the last time the diff was serviced?

The diff had it's oil changed shortly after I bought the car so about 2 years ago and less than 10k miles ago.

Given the way it happens and that it's the same amount of throttle/RPM that induces it in the noticeable gears (4th/5th/6th) that tends to suggest to me that it's engine, input side of the gearbox, as if it was the output side of the box, I would expect to have to use more throttle to get the same effect, because it's clearly engine torque related.

It's having the front engine pulley/vibration damper replaced next week and I'm hoping that solves the problem, but given that I've hoped various things are going to solve it, I'm far from sure it will

[helix402]

You have too much torque for the flywheel. I had an E46 with 607Nm and had the same problem. I had it de tuned to around 550Nm, still had the problem slightly in 3rd. Everything else was new.
I sold it and bought a 335d-the auto can take the torque.

[ridds]

Is the centre bearing fitted correctly?

I replaced mine with a new one and being slightly misaligned it grumbled.

Also, the Prop was never meant to take the increased torque. You'll be replacing the centre bearing a lot, as I found out.

[ian332isport]

helix402 said:

You have too much torque for the flywheel. I had an E46 with 607Nm and had the same problem. I had it de tuned to around 550Nm, still had the problem slightly in 3rd. Everything else was new.
I sold it and bought a 335d-the auto can take the torque.

What he said. My old 330d with a silly map did the same.

In high torque situations, I think it’s fully compressing the springs in the dual mass flywheel. What you’re hearing/feeling is vibration from the engine passing undamped into the gearbox. Lifting off the throttle slightly allows the flywheel to release, so it can do it’s job properly. Mine was the same after fitting a new clutch & flywheel too.

If you don’t have a remap, it could be the flywheel needs replacing if the springs are weak.

I just learnt to drive in such a way that it didn’t happen very often.

[e21Keith]

Had 2 330d manuals with remaps.

First one had to problem, but had a solid flywheel conversion.

Second one with same remap had the same problem as you're experiencing, had a DMF, I even replaced the DMF but it made no improvement.

So I'd agree with too much torque for the DMF.

[RicoOS]

e21Keith said:

Had 2 330d manuals with remaps.

First one had to problem, but had a solid flywheel conversion.

Second one with same remap had the same problem as you're experiencing, had a DMF, I even replaced the DMF but it made no improvement.

So I'd agree with too much torque for the DMF.

It did it before the remap and the DMF was brand new then, so clearly that's not going to be the issue.

[njw1]

If you changed the dmf at the same time as the remap it could be that your old dmf was on it's last legs and the new dmf is now being overwhelmed by the torque hence the problem remains?

[RicoOS]

njw1 said:

If you changed the dmf at the same time as the remap it could be that your old dmf was on it's last legs and the new dmf is now being overwhelmed by the torque hence the problem remains?

Unfortunately not, the remap wasn;t done till about 6 months after the DMF and clutch were changed, hence the "mystery".

It will be interesting to see if what seems like the last possibility, which is that the front pulley and mass damper on the crankshaft is the issue, but that's expensive, but on the other hand I want the car right and I love it, so I'm going to track this damn problem down.

[Santacruzjack]

We’re sad enough to look at, break, fix, tune these day in day out.
I’d put money on dmf. Same issues on my daily, 700nm, new flywheel lasted 3k and a track day.
Running paddle and solid flywheel now, cured the issues with no surprise.

People seem to have better luck with sachs dmf or running 550i stuff.
Personally single suits me, and my use.
Will be going twin plate with next power upgrade if I have any more issues
Got a cg motorsport clutch at moment.

[RicoOS]

Hi all, just thought I'd give you all an update as the problem is now fixed. What was it you ask?

The front crankshaft pulley and vibration mass damper. Which kind of makes sense, just wish the fecking thing wasn't over £270 and with new belts and tensioners and labour, I'm now some £600 lighter, but the problem is solved.

Regards