Think this is oneczechT698 said:
Engine Idle Noise 3.0i Pre facelift Updated Pg 3
- Thread starter DaveRom
- Start date
I most certainly will !
As the damper /pulley is efffectively in two parts joined by a moulded rubber interface, the outside element of the assy will have a larger inside dia. (guess + 10mm from the cutaway drg. )This may be the reason why the noise only becomes apparent when the engine is hot - ie the bigger dia will expand more, albeit only slightly more, thus creating a bit of extra clearance. I haven't done the sums - but probably will - its only schoolboy stuff! Only if its a fixed fault tho'.
They have said that the assy does also show signs of deterioration.
I collect the car today
Watch this space,.
As the damper /pulley is efffectively in two parts joined by a moulded rubber interface, the outside element of the assy will have a larger inside dia. (guess + 10mm from the cutaway drg. )This may be the reason why the noise only becomes apparent when the engine is hot - ie the bigger dia will expand more, albeit only slightly more, thus creating a bit of extra clearance. I haven't done the sums - but probably will - its only schoolboy stuff! Only if its a fixed fault tho'.
They have said that the assy does also show signs of deterioration.
I collect the car today
Watch this space,.
ronk, sorry to hear that 
I´m interested to see what the outcomes will be... I had several forums saying "hydraulic lifters" and that the solution was to rev the car for 1/2 minutes at a stationary position at 3000RPM as the air gets sometime trapped in the lifters and requires stable conditions to escape again - can be cause by lot of town driving, as for me I mostly use the car to get my ass down to school so I am often in traffic 
I´m interested to see what the outcomes will be... I had several forums saying "hydraulic lifters" and that the solution was to rev the car for 1/2 minutes at a stationary position at 3000RPM as the air gets sometime trapped in the lifters and requires stable conditions to escape again - can be cause by lot of town driving, as for me I mostly use the car to get my ass down to school so I am often in traffic czechT698 said:ronk, sorry to hear that
I'm sure the noise is not that, as the frquency is at engine speed.
My car gets a good run most of the time as being retired there is rarely need to venture into rush hour / busy time traffic.
My dealer is going to replace an idler pulley ( underneath the alternator) and water pump next month so one way or another I will get to the bottom of the problem eventualy. It's only a matter of time an it seems elimination, step by step'
I' ll let you know when its fixed - Infact I'll shout it from the rooftops!
ronk said:
Not yet no. I decided to live with it and enjoy the car for a couple of months however it will be going back at some point over the next few weeks. Maybe even this week if i can get a replacement car sorted out while it's in.
The oil pump is what is causing the noise. I had mine replaced back in January along with the chain and it went completely. Unfortunately it came back again after around 3 months. I went back to have it looked at and ended up having the vanos replaced along with other bits and bobs around that area. But it was still there.
I took it back again and asked to speak to a technician who confirmed it was the oil pump. He said it was quite common on these engines and that i should give it a few months to see if it gets any worse. He briefly explained what was happening with it which is why i asked on here if other people were experiencing the same problem He did assure me that no damage was being caused but i'm not so sure. Something is obviously wrong somewhere for the pump rotors to become noisy after only 3 months and its VERY rare i drive the car hard.
So next time it goes back i might not see it again for a while but as long as it's repaired properly and the problem cured it'll be worth it. Apart from this annoying thing the car is almost flawless. I don't suffer from the rattles and other stuff people seem to be reporting and (fingers crossed) i hopefully won't.
Also as i had the work done under warranty the pump and chain change should be done free of charge. Sandal offer a 2 year warranty on parts they supply and fit so i suppose it's really in their interests to get to the bottom of this or i could be going back forever.
I'll keep people updated on what happens.
**UPDATED - CAR IS GOING BACK IN ON THE 28TH OCTOBER SO HOPEFULLY THIS WILL FINALLY BE SORTED**
Thanks
After almost 12 months of this problem melting my mind it looks as if it's finally been cured. This might not work for everyone but in my case it seems it's been fixed.
I ended up dropping the car off monday morning and got it back tonight. The cause of the problem was worn crank bearings at No1 & No6 cylinder along with the previously damaged pump. All the other bearings were fine. The noise that the engine makes is apparently a pretty common problem however it shouldn't be no where near as loud as it is in the videos or as loud as my car was. Luckily there was another Z4 there that my car could be compared with and it highlighted how shonky mine sounded.
Anyway after making the 10 mile journey home i let the car tick over outside while i had a listen for the dreaded noise and i can honestly say it's now near silent. I had to crouch in front of the car and it can only be heard very very faintly.
Obviously i'll need to give it a few months to see if it returns but fingers crossed it's now gone. The technicians are happy they've sorted it so we'll see.
Cheers
I ended up dropping the car off monday morning and got it back tonight. The cause of the problem was worn crank bearings at No1 & No6 cylinder along with the previously damaged pump. All the other bearings were fine. The noise that the engine makes is apparently a pretty common problem however it shouldn't be no where near as loud as it is in the videos or as loud as my car was. Luckily there was another Z4 there that my car could be compared with and it highlighted how shonky mine sounded.
Anyway after making the 10 mile journey home i let the car tick over outside while i had a listen for the dreaded noise and i can honestly say it's now near silent. I had to crouch in front of the car and it can only be heard very very faintly.
Obviously i'll need to give it a few months to see if it returns but fingers crossed it's now gone. The technicians are happy they've sorted it so we'll see.
Cheers
I'm pleased to hear that you've eventualy got to the bottom of the problem - but now have the problem of getting my dealer to sort mine out! The problem is worse than I thought - I was sure it was an externally generated noise.
Perhaps you could pm or e-mail me the name and contact details of your dealer who sorted the problem. At least it may save him some effort - No sense in inventing the wheel again!
Perhaps you could pm or e-mail me the name and contact details of your dealer who sorted the problem. At least it may save him some effort - No sense in inventing the wheel again!
My dealer still can't identify the noise and as the BMW used car warranty only allows him to replace parts that are worn /damaged / broken, is reluctant to get into the change a part and hope scenario, as they will then have to pay the costs if that part is in working condition.
I now have to take the car back to them on the 15th Dec to let the travelling BMW tech guru have a listen! I'm only hoping he does not try the "They all sound like that sir"!
I now have to take the car back to them on the 15th Dec to let the travelling BMW tech guru have a listen! I'm only hoping he does not try the "They all sound like that sir"!
bulldog5046
Member
i'd be very concerned if big end bearings were the reason for everyone having this sound.
i can understand why in your case they have failed, oil pump failure would cause oil starvation and it takes all of about 30 seconds with no oil feed to kill bearings.
depending on how much damage was done would effect the cost of the repair; but, i would estimate something like £700-1000 for a new crankshaft, bearing kit and fitting.
the noise in the videos does not sound like big end failure, it sounds like a worn roller bearing as suggested, something like P/S pump.
i'd be interested to have a look for myself, i'll check over mine see if its just something i've not noticed.
Ry
i can understand why in your case they have failed, oil pump failure would cause oil starvation and it takes all of about 30 seconds with no oil feed to kill bearings.
depending on how much damage was done would effect the cost of the repair; but, i would estimate something like £700-1000 for a new crankshaft, bearing kit and fitting.
the noise in the videos does not sound like big end failure, it sounds like a worn roller bearing as suggested, something like P/S pump.
i'd be interested to have a look for myself, i'll check over mine see if its just something i've not noticed.
Ry
