My C216 makes a Grinding noise.

[CDL]

I have an intermittent grinding style air noise coming from the air suspension pipes. The suspension pump is a little loose/has a little play. Wonder if anybody has seen this and what the cure is. New filter? New pump? etc

 

[CDL]

Meant to add it’s a 2012 CL500

 

[Blobcat]

Hello and welcome

@Craiglxviii

 

[bembo449]

this maybe helpfull if you could do us a video of this happening pal , welcome aboard

 

[Craiglxviii]

I have an intermittent grinding style air noise coming from the air suspension pipes. The suspension pump is a little loose/has a little play. Wonder if anybody has seen this and what the cure is. New filter? New pump? etc

Air suspension or ABC? I don’t think the 216 had Airmatic as an option.

 

[sausage]

See if you cannot secure the pump. Moving parts do not like having an infirm base.

Waffle alert:
Mid Atlantic ocean I had to secure a poorly fitted marine engine - there was no way Desty's Marine had fitted it properly because the horizontal bolts on the fitting bracket interfered with the vertical bolts - impossible to tighten up. I got the bolt cutters out and cut a slot into several large washers. I then hammered the washers over the bolt (stud) and clamped the nut down to to the washers thus securing the lose side of the bracket. You might be able to find a way to secure the pump better and you might find that the noise is worse simply because the pump is moving around too much every time it does some work.

Could it just be the pump priming itself periodically?

 

[Craiglxviii]

See if you cannot secure the pump. Moving parts do not like having an infirm base.

Waffle alert:
Mid Atlantic ocean I had to secure a poorly fitted marine engine - there was no way Desty's Marine had fitted it properly because the horizontal bolts on the fitting bracket interfered with the vertical bolts - impossible to tighten up. I got the bolt cutters out and cut a slot into several large washers. I then hammered the washers over the bolt (stud) and clamped the nut down to to the washers thus securing the lose side of the bracket. You might be able to find a way to secure the pump better and you might find that the noise is worse simply because the pump is moving around too much every time it does some work.

Could it just be the pump priming itself periodically?

No, if it’s ABC and the pump needs priming then it’s already destroyed.

 

[Naraic]

It is ABC.

 

[Craiglxviii]

Ok. The filter is in the black header tank (on the end of the low pressure return, not in front of the pump intake). That could rattle but shouldn’t make a grinding noise.

The pump is a tandem power steering/ suspension unit; if a grinding noise is heard however I’d be checking fluid pressure. Anything below 120bar is suspect and the system shuts down below 80bar. 180bar is healthy pressure.

OP, are you getting any white or red cluster warnings? ABC DRIVE CAREFULLY or VISIT WORKSHOP?

 

[brandwooddixon]

Could be related to this - https://www.tsbsearch.com/Mercedes-Benz/LI32-50-P-048280

 

[Craiglxviii]

Could be related to this - https://www.tsbsearch.com/Mercedes-Benz/LI32-50-P-048280

That’s a good find!

 

[brandwooddixon]

Sound proofing is so good on the 216 that I don't think that engine noise would drown out the noise of vibrating pipes when sat inside the car. I believe that the ABC pipes run down the left side (as seen when sitting in the car) of the chassis.

 

[Craiglxviii]

Sound proofing is so good on the 216 that I don't think that engine noise would drown out the noise of vibrating pipes when sat inside the car. I believe that the ABC pipes run down the left side (as seen when sitting in the car) of the chassis.

That page you linked does specifically mention it. The 216’s (and 215’s) NVH pack is excellent for sure but there’s a big difference in NVH modes & isolation between engine vibrations and hydraulics.

 

[brandwooddixon]

That page you linked does specifically mention it. The 216’s (and 215’s) NVH pack is excellent for sure but there’s a big difference in NVH modes & isolation between engine vibrations and hydraulics.

Yes. I just meant that vibration transmitted through the chassis into the cabin is probably more noticeable than the engine noise, from the inside. If checking on the outside then I suspect the engine noise will easily drown out any vibration noise through the pipes.