Hi all, my 612 has developed a whining noise recently i have uploaded the video on idle in the bay and with a little rev. Its a very Similar noise to one i have on my BMW 535D when the A/C is engaged. Hence my first check was on the A/C system. 1. So far in my diagnosis first to eliminate was the A/C compressor its about 5 years old and a new one was fitted before i purchased it. Pressure is a little low at 25 PSI but it still has a reasonable amount. In the car the A/C only blows cool on LO and most of the time hot on 18deg. Its either hot or cold it doesn't seem to regulate. The code reader points to the Sensor within the Delphi control unit for that though. A/C engaged or not the Noise remains so im assuming that's not the issue. 2. Power steering fluid is toped up and at the max level. There is a different ticking noise occasionally and im assuming its this. Is the correct measurement to screw it in for the reading or a Dip into the Stick in for a measurement? its not been changed so maybe a Fluid change would eliminate the PAS. 3. A year ago the Belts were changed at Foskers but as the Hill Bearings were new as of the previous Belt change Foskers said they were ok on every other Belt change. on the way home from Foskers the Alternator Voltage regulator packed in. So i new Alternator and aux belt were fitted. this is my least favored diagnosis could we whine be from the Bearings ? .... i do hope not. Has anyone has this issue before. Thanks,
My 612 made a similar noise after I purchased it and it was because the power steering was low on fluid. But mine did not seem quite as loud as your video indicates. I also had some leaking power steering hoses, the two hoses from the reservoir to the pump. I replaced the hoses with new ones from Aeroquip, then flushed the system and serviced with all new fluid. The noise went away and has not returned in 8k miles of driving. The correct procedure for checking the power steering fluid is 1) car must be warm, as after a minimum of 15km drive. 2) Reservoir cap installed and fully closed. 3) Engine off. 4) Remove the cap and check level on the dipstick. It should be between the upper and lower fill marks. 5) If necessary, fill reservoir to the "full" mark on the dipstick. 6) Replace cap. Section E3.01 of the workshop manual addresses power steering servicing, and specifically states that if the power steering pump seems "loud" after servicing, then a complete fluid change and system bleed is necessary. I have read on this forum that the power steering pump is generic to many other cars and is inexpensive to replace (others here may comment on that). As for your air conditioning, I had a similar problem and servicing the system with the proper amount of r134a restored normal system operation. I sometimes see "Delphi climate control system" faults when I run a diagnostic scan, but the system seems to work perfect with no noticable issues. I normally use "fully auto" mode on the controls. My guess is your power steering pump is making that noise. Maybe pull the front undertray, place the car on a lift, and have a good listen from underneath? It should be obvious then. Good luck and let us know how it turns out.
Thanks for the advice. Tbh id say its due a change regardless so will get sorted while its off the road for winter.
