Horrible noise but I don't want to jump to conclusions yet

[wrightkarl]

My ever demanding R230 5.4 is making a horrible noise, I'll try my best to expalin...

A few months ago the power steering hose burst, its been repaired (MB don't supply the hose anymore so Pirtek sorted it)
Since then there is a really horrible whirring noise especially at low speed (maybe obvious?) which is much louder in the car then under the bonnet. Everything sounds sweet when cold and even warming up but drive a few miles and the noise is back. So I assumed that when the hose busrt the stearing part of the tandem pump must have run dry or low enough on fluid to cause damage BUT when I hold my listening stick to the pump body its not sounding bad. So maybe it isn't the pump, maybe its something esle ???? The fluid is fine.

I'm not familiar with the steering and pump as a system, so any pointers ????

Thanks

 

[ajlsl600]

https://mbworld.org/forums/mercedes-tech-talk/493228-tandem-abc-power-steering-pump-rebuild-kit.html

 

[wrightkarl]

https://mbworld.org/forums/mercedes-tech-talk/493228-tandem-abc-power-steering-pump-rebuild-kit.html

I'm just being optamistic in that it could be something else. Taking one out and all that goes with it is probably beyond my facilities

 

[ajlsl600]

I'm just being optamistic in that it could be something else. Taking one out and all that goes with it is probably beyond my facilities

suggest you look an independent mb man near you. prob wont cost much for him to listen to whats going on .

 

[Uncle Benz]

I've not seen on Mercedes, since I'd usually fit a new hose, but there have been issues with BMW M3's, particularly of E46 flavour, where a steering hose often bursts and the replacement is very expensive. An enterprising member decided to save forum members a few bob by making a replacement. Unfortunately he used (and I can't remember which way round this is) a steel reinforced hose where original was cotton reinforced (or vice versa). The upshot was the one he used made a horrendous whirring noise. This might be your problem since the hose was repaired probably with non original pipe.

 

[LostKiwi]

There is a pulsation damper which is part of the ABC system. It's job is to reduce the variations in pressure caused by the pump running. When the damper fails it makes a loud whining noise. Possibly that?

 

[ajlsl600]

There is a pulsation damper which is part of the ABC system. It's job is to reduce the variations in pressure caused by the pump running. When the damper fails it makes a loud whining noise. Possibly that?

thought about that , but given the op sayin steering pipe changed and noise developed after. it would be real bad luck for an abc related issue to pop up now unless it was disturbed in the steering pipe replacement saga .

 

[wrightkarl]

I've not seen on Mercedes, since I'd usually fit a new hose, but there have been issues with BMW M3's, particularly of E46 flavour, where a steering hose often bursts and the replacement is very expensive. An enterprising member decided to save forum members a few bob by making a replacement. Unfortunately he used (and I can't remember which way round this is) a steel reinforced hose where original was cotton reinforced (or vice versa). The upshot was the one he used made a horrendous whirring noise. This might be your problem since the hose was repaired probably with non original pipe.

Its a thought, although I'm a bit stuffed as MB no longer supply this pipe, thus the repair. It was done by Pirtek, maybe a benifit or not, just the go-to eople for hydraulic hoses.
I can't trace the noise but its much louder in the car than under the bonnet, makes me wonder ?!

 

[wrightkarl]

thought about that , but given the op sayin steering pipe changed and noise developed after. it would be real bad luck for an abc related issue to pop up now unless it was disturbed in the steering pipe replacement saga .

Its a thought, but this is why I'm keen not to jump to expensive conclusions. Its going to have to go to my indy for a paid investigation, bugger ! This car has been a pain in the rear since I bought it..... and I'm still not convinced the ABC is working properly ! Ho Hum

 

[ajlsl600]

Its a thought, but this is why I'm keen not to jump to expensive conclusions. Its going to have to go to my indy for a paid investigation, bugger ! This car has been a pain in the rear since I bought it..... and I'm still not convinced the ABC is working properly ! Ho Hum

unfortunately there are a number of cases where the correct expertise/diagnostics need to be employed . frankly if yr not that handy at resolving many issues yrself and dont have the resources/desire to pay out , this may not be the car for for you.. no pop at op here . i had my r230 biturbo v doz a number of yrs and hated moving it on. i KNEW it was going to bite me in the arse at some point and was not prepared to throw small car money at it somewhere down the road. so away she went . I WILL LIKELY NEVER OWN such a great car again. but I DID have one .

hope you find an economic solution..check pipe internal I/D same as original ?

 

[Kev555]

Could be a hydraulic issue as Lostkiwi nicely explained the pulsation damper on the power steering system. If the pipe was a slightly different internal diameter I wonder would that trigger the pulsation damper to make the noise? through the years ive came across flow problems in hydraulic sytems before with wrong internal dia pipes installed as a cheap replacement as ajls600 noted above. Would recommend a trip to indie first though before purchasing expensive pipes

 

[ajlsl600]

Could be a hydraulic issue as Lostkiwi nicely explained the pulsation damper on the power steering system. If the pipe was a slightly different internal diameter I wonder would that trigger the pulsation damper to make the noise? through the years ive came across flow problems in hydraulic sytems before with wrong internal dia pipes installed as a cheap replacement as ajls600 noted above. Would recommend a trip to indie first though before purchasing expensive pipes

is the pulsation damper not related to the abc circuit only ?

 

[LostKiwi]

is the pulsation damper not related to the abc circuit only ?

Yes it is. It's only linked through the tandem pump but not hydraulically.

 

[ajlsl600]

Yes it is. It's only linked through the tandem pump but not hydraulically.

as i thought. so it would be real bad luck for a defect there to coincide with the OP steering issue. unless pipework removal involved dislodging abc pipework

 

[umblecumbuz]

The old rule possibly applies here:
'Last thing changed is first thing suspect.'

 

[brandwooddixon]

Personally I'd suspect an issue with the pump if there was a loss of oil.
It's possible that although not badly damaged it is no longer pumping as it should. At low levels of damage this will show as erratic/noisy pressure levels in the hydraulics.

I know that this can be read on STAR for the ABC, but I don't know about the steering side.

When I had an ABC pipe burst on my last car, all appeared okay, except that you'd get a loud humming noise at high speed or when hot, but it didn't occur in a way that you could safely check when the car was stationary in a garage. It was only fixed by a replacement pump.

 

[ajlsl600]

The old rule possibly applies here:
'Last thing changed is first thing suspect.'

spot on.......

 

[wrightkarl]

Personally I'd suspect an issue with the pump if there was a loss of oil.
It's possible that although not badly damaged it is no longer pumping as it should. At low levels of damage this will show as erratic/noisy pressure levels in the hydraulics.

I know that this can be read on STAR for the ABC, but I don't know about the steering side.

When I had an ABC pipe burst on my last car, all appeared okay, except that you'd get a loud humming noise at high speed or when hot, but it didn't occur in a way that you could safely check when the car was stationary in a garage. It was only fixed by a replacement pump.

I thought the same but the pumps works exactly as it should and the noise doesn't seem to differ on use, say lock to lock. I also expected that if the pump was damaged that it would get worse or at least show a sign of change in noise or operation. ut no, it works fine.

 

[LostKiwi]

Does the noise change note with RPM?

 

[John Laidlaw]

Sad to say my 230 made a very similar noise to what you describe , which I tried to convince myself was pulsation dampers or spheres...however ultimately it was the pump.
Not the end of the world , if I remember correctly the MB Exchange unit was c£850 plus fitting at the time might be cheaper now. Unfortunately you will need to wait to get it on star to confirm , hopefully I’m wrong ...
Edit: available here
https://www.abcspecialist.nl/en