Bilbo7

Hi
I have vibration at the UK passengers foot well being drivers in USA and steering every 20-30 seconds but outside f the car its not heard sometimes with noise

So I am assuming this is the pulsation damper piggybacked on the ABC pump?
The real vibration my wife says is at the left of the footwell.............. is just the interconnection pipe lacking that dampening ?
The ABC pump is at the bottom of the engine visible from the front looking downwards

BUT the location of the pump and the Pulsation Damper that causes this problem seems to vary on different sites and R230/231 cars but I think that's confusion with the accumulators in front and rear wheel arches ???

Cars driving fine no problems just the VERY worrying vibration and noise only heard within the car worse at very low speed

So far I cannot see the actual damper from above is it only visible after removing the underside engine body car

Other sites say it a relatively easy part swap/fix if it's on the pump

Currently waiting return of my car jack and stands GRIN..........

Any advice and particularly images would be appreciated

So far I am only think of fitting a new pump pulsation unit and changing the filter and an oil top up

I could do a full oil flush but it was changed 2 years ago

BlownV8

From my experience, the vibration you are experiencing is often an ABC pump on the way out. Take to a specialist to diagnose before you throw good money after bad. Good luck!

TomZVB

The R231 pump is much more reliable than the parts on the R230 cars.

Easy fix… pulsation damper on the pump... the nitrogen fill has bled out. I had the same issue on my SL 63 and fixed it with a new one from FCP Euro.

Bilbo7

Hi thank you both for the replies
BlownV8 I think you’re a half empty glass type whereas Tom maybe more like me a half full beer glass person GRIN

So optimistically it’s just the pulsation damper and that’s not expensive as to FCP Euro well I am on the other side of the pond in the UK
Just had a look at their site its extensive in the number of parts they stock
So I hopefully will order one on line if not from a dealership

If its not that part well I can always sell it.

TomZVB

I’m hoping to maintain my half glass full outlook on things but I just ran into my own issues with ABC this morning - hoping just accumulators

Replacing these is a good preventative measure with mileage/age. Worth it to do.

Haven’t really heard much about pump
failure on the R231 cars. They’re no longer a tandem pump and located at the top of the engine - not a hard job if you needed to do it.

Bilbo7

Sorry to hear that Tom

Ordered pulsation damper but
but when I call my local main dealer this service filter only comes with the whole header tank

I find that hard to believe

So I now need a source in UK for the header tank filter for 2015 231 SL63AMG and I believe these are now 3 micron filters

Anyone have a source for them or the actual part number........think I will start another thread

TomZVB

I had the same discussion with my local indy mechanic when scheduling the accumulator repairs (decided not to do myself). I will replace the filter myself after the accumulators are done - I believe that FCP Euro has the filter (they advertise as such).

Bilbo7

Hi Tom
Thank you for the reply

I looked at FCP Euro but they are on the wrong side of the big pond as I am in UK
https://www.fcpeuro.com/products/mer...ter-0031846101

However, they only list it for 2009 and 2011 and using the part numbers they list all say its for a SL63 AMG and R230 and not R231 (SIGH)

I have asked AMG a week ago but no reply other than they are checking for a part number

Bilbo7

Well I bought an exchange pulsation damper from a Mercedes main dealership plus a litre of fluid that at the price seems made from liquid gold and I never needed the fluid anyway! So damper and oil cost £218 but the damper is exchange but the parts department had no idea of how much and I never waited to find out. I will let you know when I return it

Changing it has been delayed as many write up say the damper is in the wing that's wrong that's an accumulator and other say its below the engine that's also wrong.

It is at the top of the engine behind the black dome and pulley those being the ABC pump and is mounted on the rear of the pump

Hardest job was getting the top cover off as I had never done this before.


The ABC pump is black done on the left with the pulsation ball on the right

I bought a stethoscope off amazon to check the pulsation damper etc for noise but there was no noise from the pulsation damper ball or the pump but lots of noise from the silver pipe on the top which I believe is the delivery pipe and no noise from what must be the return pipe not in this image

The nut on the rear of the pulsation damper is 17mm and takes a normal size ring spanner but it was stuck fast as in effect heat welded but 2 sharp but not OTT hard taps from a woodworkers small mallet cured that problem. After just half a turn you can unscrew it with your fingers

Before starting and on completion I cleaned the area with a big spray of carburetor cleaner and then let it evaporate. I also checked the fluid level and it was just below the upper level when the engine was not running being 2" above the lower level for engine off and the oil was cold so its over filled . Its had an oil change by selling Mercedes Main dealership!

In unscrewing the damper you do need to move a small vacuum line out of the way and the damper was snagging on the jubilee clip on the short air inlet hose. That really should be designed 180degrees and on top to be out of the way but I just slackened the clip and pulled the knurl screw body out of the way

All black pulsation damper on rear of pump with top clip knurl screw pulled out of the way to remove it

So during removing it there was no high pressure jet of oil in fact no drips; I had been concerned that it would be pressurized!
I don't have a torque setting for the damper and my torque wrench is 1/2" drive anyway and there is not enough space in length to fit one in place with a standard length socket. However, I can borrow a 3/8" torque wrench and cut down the height of a 17mm socket with and angle grinder. So I put the pulsation damper back with a couple of taps with a mallet and that ring spanner and so far after a run so far and NO NOISE. Now there is also no loud noises from that outlet pipe just a normal bearing sound

The fluid level after a 3mile runs the same with the engine off. I will lower that level tomorrow with a syringe to just above the lower mark for pump off. The pulsation damper was not filled with oil only say a tablespoon full, so it can only be a pin hole no massive slit or rupture of the internal diaphragm in the pulsation damper

This is the old unit with a top sealing cap that came with the new one and its box with part number


2015 Sl53 AMG parts box old unit and cap from the new one to seal the top

The pulsation damper unit failed driving back from Spain after we stopped for coffee some 10 miles before the French border and I continued home but the noise increased a tad about 200miles from home. So its been like this for about 650miles and the ABC so far is working fine. You could easily change the pulsation damper in 20minutes without rushing

Causes:...... well we were staying a Spanish town with lots but not tall speed bumps but it failed later after 600 miles on the way home on the first days drive so I think unrelated.
It was a hot 32C day but I think at 33,000 miles and 9 years old it just failed. When I bought the car in 2022 it had done 20,400 miles and all the bits that are failing have some rubber content its well known that any bushes and dampers and maybe diaphragm unused or little used to harden and fail

I might over the winter on that basis change the accumulators as preventive maintenance.

Oddly looking at the engine to check the oil I thought something looks odd thought the same looking at it when the pulsation unit failed and when I took the engine cover off I realized the Mercedes Star at the fronts missing. You can see 3 holes where pins must hold it in place and 2 or 3 pins that are broken off, I have no idea when this happened but it must have partly or fully broken away during a service.

I have not been using the car but need to for a 3 mile trip last week and run the Intelligent Lighting system inoperative and related to Right Hand Drive warning came up but oddly the lights still dance on start up. So that's the next job and MOT runs out in 6 days.

Still we were caught in a flash flood storm in Spain and raised the suspension but that was 1800 miles ago so I hope unrelated to the lights and damp or water. Plus I need to order a knew star for the engine cover