Originally Posted by erm324
Great post! Always love your inputs on stuff like this.
Anyways, my car never made a single sound up until a few months after I put the blower on. It got pretty noticeable a few months in, I just recently took the blower off and the sound is still present, but it seems to be very very faint (not as loud of a ticking). This is extremely weird, for if the ticking was a bearing issue wouldnt it make the same noise all the time in direct correlation with the crank? Could it be related to the stress on the motor as well? Meaning for example after doing 5 consecutive 60-130 pulls with 8lbs of boost in the motor it would tick alot louder then, as opposed to me just driving around naturally aspirated. At first when I got the car back I didnt hear any sounds so I thought the ticking had to do with the blower, but then the past few days I've been paying very close attention and the sound still is there, but nowhere near as loud or prominent. Does this make any sense? To me it doesn't, because a bearing on its way out would make the same noise all the time, but you obviously know alot more than me so I figured I'd ask..
I can't say for sure what the ticking is in your engine, but, I can tell you I have some intermittent ticking that sounds just like that in my car but it only occurs right after an oil change, and then it goes away completely after a few days. Since it is an intermittent tick, I have concluded it is valve train noise in my car. Since hydraulic lifters don't like heavy oil, I think that the 10W60 needs a chance to shear down a bit (as it has been known to do) and then the lifters are happy with the viscosity. One thing I am sure of, is if the noise comes and goes it most likely isn't a bearing noise. The S65 has a noisy valve train, and hydraulic lifter noise can come and go at varying volumes and frequencies. Bearing noises almost always start off subdued and get louder and louder as the issue progresses, until finally there is a failure or excessive loss of oil pressure, enough to turn on the oil pressure warning at idle usually. One thing to note about bearing noises, is that they have a specific frequency and it is directly related to engine RPM, they are almost never an intermittent noise.
Take the car out and drive the piss out of it, Lots of high RPM/redline driving. This will do two things, 1)It will ensure the lifters are full and all air is blead out of them and 2)The oil is at full operating temperature. One other thing of note is that the check balls in hydraulic lifters sometimes won't seat properly seat if there is debris in the oil. ensure you are changing the oil at 7500 mile intervals max, BMW's recommended oil change intervals are just plain too long.
Keep me up to date on how you make out, I am very interested to see if your engine stops making this noise!