This is not a new problem, its been a feature of my car all the time I have owned it. The issue is a very loud oil pump whine. This is not only when cold but all the time. The noise can easily be traced to the pump using a stethoscope but it causes the oil cooler to act as a loudspeaker which transmits it out through the ducting and the side duct. Its the loudest sound in the car at certain revs, louder than the exhaust and its really annoying. I thought the problem had gone when changing to a different oil, Mobil 1 0W-40 but in fact its still there. I might try a thicker oil such as 10W-60 but I am not sure why this noise is louder from my pump than others. Its relatively low mileage, 30K. Any thoughts welcome.
My 328 does the "whine" from the oil cooler but only on cold start and with ambient temps below approximately 50-55F. It usually goes away in a couple of minutes. I just ignore it although it IS embarrassing if other people hear it. FWIW, a local shop did the car's first oil change and they used 20w50 so it had that for a couple of months until I switched to 0W40. I seem to recall it was a bit more whiney with the 20w50 but that was almost 9 years ago so I could be mis-remembering... If it does it all the time, I agree that would be incredibly annoying. Maybe a different weight oil WOULD help. Maybe there is some variation from engine to engine or it could be slight variations in the plumbing of the oil system causing differences in the "resonance" frequency.
What does it sound like? Does it sound like a power steering pump at lock? That sort of noise? Our car makes a whine like that only when cold and goes away before I can really think about it. The car makes so many different noises it is hard to know the good from the indifferent from the bad sometimes Franny
It is the same whine that most of these cars make when cold, but it does it all the time, not only when cold. Yes it is the same as a PS pump at lock.
Hmmm...you are right - it is that same sound. Does anyone (RifleD?) know if there is some sort of bypass valve in the oil system that, when cold could cause the "thicker" oil to be bypassing the filter? That could explain it - the bypass valve in the PS pump is what causes the whine when the steering is at full lock.
I have just taken out the bypass valve spring, plunger, spacer. Cant see anything untoward with them. Image Unavailable, Please Login
What I'm wondering is IF the noise could be caused by a bypass valve vibrating. Sometimes old-style water faucets in a house will vibrate/make a whine/scream sound when the handle is in a certain position and the seal/water flow creates the vibration/noise. Opening the valve further stops the vibration/sound. So I'm thinking that MAYBE the noise is the valve pulsating under certain conditions. I am just speculating here, nothing else...
It could well be the bypass valve vibrating. The question I have is, on cars were this noise goes away when hot, does the noise completely stop, or just get very quiet? If it completely stops it might indicate the valve is opening when cold and the oil is thicker but stays completely closed when hot. But mine seems to still be opening when hot. There was a service bulletin about a weaker spring being used on later cars but the change was May 1987 so there would be plenty of other cars with the weaker spring. But what I might try is adding a shim to the spring and see if it makes any difference, and record oil pressures before/after. The spring length was changed from 76mm to 72mm and mine does measure 72mm. I will try adding a 4mm spacer.
Is it the oil pump? I always thought that whine was from the drop gears, Dino’s makes the same noise.
Helidoctor had this problem on his GT4..He traced it down to sticking buckets/ lifters Lack of lubrication..
