E46 Fanatics Forum banner
1 - 9 of 9 Posts

·
Registered
2002 325i
Joined
·
41 Posts
Discussion Starter · #1 ·
I am quite stumbled upon what sound I am hearing at this point. At first my car made a very odd whining sound on deceleration mainly in second gear, as I drove with it eventually I could hear almost like grinding gears sound at idle. When I pushed the clutch in/disengaged the clutch, the sound would go away gradually. This made me think alright pilot bearing since the sound goes away when I press the pedal in. No sound at idle or on deceleration when the clutch is pushed in. When I'm at a stop and let the clutch out in neutral the grinding sound at idle is very loud. This went on for about a month then I decided alright I need to do clutch/flywheel anyways so I'm gonna buy new throw out and pilot bearings. (I have a 2002 325i manual with about 231k miles on it)

The weekend comes and I replace the pilot bearing, throw out bearing, new single mass flywheel and new clutch. (The new clutch feels amazing). I bring the car out and the first thing I notice is that the sound at idle is still there. After the two days of straight pain this was such a let down. On acceleration you can kind of hear the sound but it's mainly on deceleration where you can really hear this odd whining sound. Deceleration in second gear is where it's the worst.

While we (My dad and I) had the trans off I spun the input shaft and could feel the ever so slight grittiness while spinning the shaft by hand. At first I thought this was normal, I had nothing to compare it to.

After some frustrating days of thinking what is wrong we found out about the input shaft bearing that could be bad. We ruled down to this because the sound is not speed dependent, we could be in third gear going 20mph or second gear 20mph and we would only hear the sound in the second gear not third. Not even a little bit in third. Same thing with first gear. We were looking into just the input shaft bearing and the price itself wasn't bad but doing more research the effort of taking the tranny apart and replacing the one bearing and possibly finding out that also wasn't the problem we didn't want that to happen. We called the local scrapyard up and asked if they had a getrag S5D 250G, they do, an A grade part with about 137,000 miles on it. We decided to do the whole trans not only because of the bearing we thought was bad but because its an old trans and we wanted the car to last so may as well do it the "right way" we thought was the best option at the time. We also thought of how when we spun the input shaft it made the gritty feeling which was very settling.

Fast forward, we install the new trans (we spun the new input shaft bearing and it spun so smoothly compared to the old one) and swap over anything we bought new.
At this point I have a new pilot bearing, throw out bearing, a 137k mile trans, clutch, flywheel, everything down there it feels like.

A couple weeks later, which is now today, I am having that same problem. No sound at idle. A very odd whine on deceleration in second gear starting at 2200rpm and as I slow down nearly stalling the car out you can hear the whine slow down and my speed slows down/ rpms lower. As far as I know I cannot hear the sound in first gear accel/decel/ and third gear accel/decel. 4th and 5th gear are fine. When I push the clutch in while it whines the sound goes away.

I am so extremely confused, maybe I messed the pilot bearing up while putting the trans in? Possibly bought a faulty part? The new trans is actually bad? Maybe it's me that is messed the car up?

Although possible, I don't think it is me that is driving so poorly that it is recreating the same problems as before. I up shift smoothly, not burning the clutch or doing race launches every day or ever. I take corners pretty hard when I can but I think the car should be able to handle that and I don't think that related to the problem. As you can see I'm grasping at anything. I am possibly thinking of the diff but wouldn't the sound react to the speed of the car?

If you have made it this far thank you for reading such a long rant, I am sure I have left some key details out so ask away if you think I'm missing something crucial. Any suggestions would be helpful at this point.
 

·
Registered
'01 320Ci manual
Joined
·
1,420 Posts
Usually the slight whine is from the diff. Have you inspected that? Drop the rear seats while driving to pinpoint the sound. Worth investigating, especially after you changed transmission and clutch
 

·
Premium Member
E30M3 Race F10 535 R1150Rt M Coupe
Joined
·
11,388 Posts
Without hearing the noise for myself, I'm thinking your issues are single mass flywheel related?
1) Does changing the gearbox oil to a thicker weight change the sound? (Have you changed it?)
2) Is the noise MUCH less when the gearbox is cold (first thing in the A.M.) and gets louder after the oil in the gearbox gets hot?
3) Do you also have other than OEM engine/trans mounts?
 

·
Registered
2002 325i
Joined
·
41 Posts
Discussion Starter · #4 · (Edited)
Without hearing the noise for myself, I'm thinking your issues are single mass flywheel related?
1) Does changing the gearbox oil to a thicker weight change the sound? (Have you changed it?)
2) Is the noise MUCH less when the gearbox is cold (first thing in the A.M.) and gets louder after the oil in the gearbox gets hot?
3) Do you also have other than OEM engine/trans mounts?
1. My father replaced the oil, "mostly D4 ATF, a little 75W140 gear oil".
2. The sound doesn't change whether it's first thing in the morning (the sound is there) or hot after a saturday drive.
3. My engine mounts are probably shot, I checked the trans mounts (looked oem) and the rubber was squishy still, I believe the previous owner changed the trans mounts before.

At idle I can hear the flywheel chatter a little bit, which I knew would happen.
 

·
Premium Member
Joined
·
4,185 Posts
Try Redline MT-90 in the trans.

It was never the pilot bearing- since it only spins when the clutch pedal's depressed
the only time you'd hear it is with foot to the floor.

Noise at idle with the clutch out's not unusual, especially with the single mass flywheel.
Should be a 'rattle', tho.

I agree with Doukas- take the rear seat out, and then have someone else drive you around.
Noise in overrun is classic diff whine. And it can do that for a looooonnnggggg time if you
keep good fluid in it. That may not be it, but good to rule it out.

One other thing- in second, keep your hand on the shifter, and then accelerate and decelerate.
The shifter will move as the engine moves around, but you're feeling for a quick 'bump'
forward and backwards as SOON as you change the direction of torque going through the gearbox.
That's the gear cluster moving. If it moves more than a mm or 2, it's indicative of too much
end float in the gearbox- and that will cause whine. Again, with good fluid, it can do that for
quite a long time...

whut I gots,
t
 

·
Registered
2002 325i
Joined
·
41 Posts
Discussion Starter · #6 · (Edited)
Try Redline MT-90 in the trans.

It was never the pilot bearing- since it only spins when the clutch pedal's depressed
the only time you'd hear it is with foot to the floor.

Noise at idle with the clutch out's not unusual, especially with the single mass flywheel.
Should be a 'rattle', tho.

I agree with Doukas- take the rear seat out, and then have someone else drive you around.
Noise in overrun is classic diff whine. And it can do that for a looooonnnggggg time if you
keep good fluid in it. That may not be it, but good to rule it out.

One other thing- in second, keep your hand on the shifter, and then accelerate and decelerate.
The shifter will move as the engine moves around, but you're feeling for a quick 'bump'
forward and backwards as SOON as you change the direction of torque going through the gearbox.
That's the gear cluster moving. If it moves more than a mm or 2, it's indicative of too much
end float in the gearbox- and that will cause whine. Again, with good fluid, it can do that for
quite a long time...

whut I gots,
t
Currently I have no noise at idle other than the rattle of the single mass flywheel. The original sound I heard at idle was unknown but went away after replaced the trans as a whole. We thought it was the input shaft bearing. At the time I had the dual mass flywheel.

I used mostly Redline D4 ATF oil then a little bit of 75W140 gear oil.

I will take the rear seats out to see if we can rule out the diff.

I'll feel for the bump you are mentioning.
 

·
Registered
2002 325i
Joined
·
41 Posts
Discussion Starter · #7 ·
Try Redline MT-90 in the trans.

It was never the pilot bearing- since it only spins when the clutch pedal's depressed
the only time you'd hear it is with foot to the floor.

Noise at idle with the clutch out's not unusual, especially with the single mass flywheel.
Should be a 'rattle', tho.

I agree with Doukas- take the rear seat out, and then have someone else drive you around.
Noise in overrun is classic diff whine. And it can do that for a looooonnnggggg time if you
keep good fluid in it. That may not be it, but good to rule it out.

One other thing- in second, keep your hand on the shifter, and then accelerate and decelerate.
The shifter will move as the engine moves around, but you're feeling for a quick 'bump'
forward and backwards as SOON as you change the direction of torque going through the gearbox.
That's the gear cluster moving. If it moves more than a mm or 2, it's indicative of too much
end float in the gearbox- and that will cause whine. Again, with good fluid, it can do that for
quite a long time...

whut I gots,
t
I just drove the car, in second gear with my hand on the shifter I accelerated and decelerated, I didn’t feel any kind of bump you were talking about. Did it multiple times, nothing.
 
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top