C180 2002 Transmition noise at + 65mph

[mearnsmerc]

During the last two months I have owned two C class 180 automatic estates. Both have had the exactly same problem: at around 65 mph when going up hill (even only a slight incline) a vibration noise comes from the transmition, diff or drive shafts.

There is no noise below that speed, when the car is on the level or going down hill. When accelerating up hill to speeds around 70mph the noise appears to reduce.

The garage from which I purchased the first car (75,000miles) refused to/could not solve the problem and refunded my money. The second car (50,000 miles) I purchased had no noise for 3 months, but it appeared 10 days ago.

Any ideas on what the problem is. if I can identify the problem component I am confident I can replace it.

Grateful for any ideas or advice

 

[television]

This could be engine mounts that affect the prop shaft or the prop shaft bearings / spiders couplings

 

[mearnsmerc]

Thanks for the ideas. Any thoughts on how I might be able to narrow it down a bit and eliminate the possibilities? Presumably the relevant mounts would be those at the gear box?

Having this happen to two cars in the space of 6 months leads me to think this is a common fault. Anyone else came accross this?

 

[television]

Thanks for the ideas. Any thoughts on how I might be able to narrow it down a bit and eliminate the possibilities? Presumably the relevant mounts would be those at the gear box?

Having this happen to two cars in the space of 6 months leads me to think this is a common fault. Anyone else came accross this?

Its the engine end, and the engine ends up out of line., We have had a few threads of this nature

 

[mearnsmerc]

Thanks. I've been working on my cars for 20 years, but this is my first merc (second if you count the one I took back!) and first auto box. Not did much on this car, or had a good look round yet.

Can you point me to the location of the mounts?

 

[big x]

Thanks for the ideas. Any thoughts on how I might be able to narrow it down a bit and eliminate the possibilities? Presumably the relevant mounts would be those at the gear box?

Having this happen to two cars in the space of 6 months leads me to think this is a common fault. Anyone else came accross this?

It might be more noticeable in the estates because the torsional rigidity of the body shell is less. Not a common problem in the saloons.

adam

 

[brandwooddixon]

I would go for engine mounts, as these tend to go first. The ones either side of the engine will probably be the culprits. The one holding the gearbox up, which MB refer to as the rear engine mount, may need to be replaced, but the main engine ones will go first.

It's not easy to determine whether they are shot by inspection alone. They are fluid filled and over time this can leak. It's a fairly easy job to replace them yourself, rather than pay a dealer to do it. I would recommend MB parts, surprisingly not too expensive, as by quoting the VIN you'll get the correct ones for your car, and better quality than pattern parts.

Check out the DIY section if you want some more pointers.

 

[mearnsmerc]

Thanks for the advice. Have ordered left and right mounts (from mec and not too expensive) and will do the job at the week end. Will let you know how it goes.

 

[mearnsmerc]

Just changed the engine mountings. No difference - noise remains.

Had a look at the prop shaft centre bearing and think there is a bit of movement in it. Could this be the problem?

Grateful for any further thoughts