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03 sl500 w/ 54k. Has a ticking sound that feels like it's coming from the accumulator on the pulsation damper (had my hand on it as wife slowly accelerated engine). Blue/ white warning light on car drives well and raises and lowers. Should I change just the accumulator or damper? Thanx
From what I have read, the pulsation damper usually makes a humming or whining noise when it has failed. I just replace mine due to a whining noise. See attachments.
Flashing warning lights most likely point to failing accumulators. Read through the attached troubleshooting guide which gives an excellent overview of the whole system.
My reading leads me to believe that the accumulators are prone to weaken over time and need to be replaced periodically, (50-60K) as part of ongoing maintenance for our R230's. I will be changing out my front and rear ones as soon as the weather warms up. I am experiencing a very harsh ride suggesting accumulators but no warning lights yet.
2003 E55, 2003 SL55, 2014 CLS63, 2018 q50 Redsport, 1968 Camaro SS, 1999 Trans am Firehawk
accumulators are rubber and essentially help maintain constant pressure. Rubber decays with use/age. 75k/10 years is really about the max life expectancy. They luckily aren't too expensive and should all be replaced at the same time. If go over a really bumpy road or a really hilly road (such that the car gets hit with a lot of downforce at the bottom of the hill) you'll often get the red ABC drive carefully light on for a few seconds. When this happens basically the system is reading a very low pressure and that the system is not keeping up. It then goes and locks all the valve blocks so that no more fluid can escape the struts temporarily as a safety precaution. This leads to the rough ride.
after getting the new pulsation dampner on, the system sounded great for a few minutes. then came the same grinding, bearing sound as before, in low rpms you can hear it w/ the top and windows up, sounds like it's coming from the parking brake pad area. goes away at high rpm, once I reduce rpm under 1k it starts up again. with the system warm, I've touched the 2 hoses on the valve that houses the pulsation dampner, one hose is warm the other cold, shouldn't they both, after warm up be warm?
I sounds like there is an issue with the pressure control valve located at the driver side wheel housing below the alarm siren. The pressure control valve has two functions. The obvious is to keep the system pressure and the second function is to provide a minimum flow through the ABC pump to avoid overheating and damage. The pump creates a flow with a certain pressure and the pressure control valve directs the excess fluid to the return line, though the cooler back into the reservoir. If the pressure control valve emits strange sounds and vibrations high velocity flow and expansion might be the reason. This can be caused by flow restrictions and cavitation in the valve cause by debris ( from the vibration damper?) or too little pressure (weak pump) which is causing the control valve to vibrate (open/close). This would explain why the sound goes away at higher rpm because the pump is producing enough flow at pressure to keep the control valve in operating range
The warm line is the high pressure line and the cold line is the return line. You will see that the return line pressure rating of the hose is only 144 bar (2150 PSI) and the pressure hose in 400 bar (6000PSI).
To make it short. Check your system pressure (about 188 bar) and if this pressure is in range check the valve for any kind of flow restrictions.
i put in a new pump and i had no flow of fluid, based on your recent response i pulled the pulsation dampner, which i had replaced 2 weeks before installing the new pump. i then started the car and the chf 11s came pouring out of the pressure control valve. put the dampner back on and everything is working fine, thank you!!!
I’m a newbie & appreciate all the help everyone shares. I have a 2003 SL500 I’m showing a n ABC Presure sensor B4/5problem and my bar is 255, should I replace abc pressure sensor, Everything on my ABC works PERFECT, I’m scared to touch “ don’t fix if not broken senario, yet I think 255 bar to high shouldn’t it be 200 max? Any help very much appreciated; STEVEO4 THANKS
Since wiring or the ABC controller could be faulty, I would not replace the pressure sensor without doing some basic electrical measurements. I would begin by checking that 5 volts DC is being supplied to the sensor. If you want to do that and request help, someone will provide you with details.
New pressure sensors are no longer available as a standalone purchase -- you must buy the complete pressure supply unit sans the Pulsation Dampener.
02-18-2016, 10:51 PM
