[AlanYoro35i]

Hey

I just got the famous rattling sound on my 335i, i search a few post regarding rattling but what i wanted to know is that since what i read was from way back, has bmw put any stardards to fixing the problem so i don't need to argue my ass off or beg them to get bmw to fix it free??

what should my next approch be? i took a video clip with the rattling sound and a video of the car starting slow.

my car is due for oil change and has gone over by 560 miles but i did book it for wednesday as they had no spaces til a week after i made the call.

does this mean i will be getting new turbo's?

If someone knows a tread then please give me the direction

Thank you
p.s m the cars still in warranty til end of may and under average miles so its a good thing it happened now?

[Yahoo]

This is probably the wastegate rattle. BMW released a software update to resolve this. A software update will be the first port of call - although it will probably take 5 trips to the dealership to diagnose the problem.

I haven't had this issue, I'm sure others will contribute that have had this resolved.

[doughboy]

Mines an 09 LCI which supposedly has new design wastegate pivot shafts that are meant to prevent it. But I think there's more to it than that....

As soon as I had the DPs fitted you could hear the wastegate rattle, on cold starts its bearable like a pulsed raspy jangle that subsides fairly quickly, but its a harsh sound.

Worse though on warm starts (say stopped for 30 mins minimum) it's just a loud tick, tick, tick, tick, tick - just like a very loud single tappet rattle - which fades over 30 seconds.

But then it if you blip the throttle the 'tick' increases with engine speed, so it sounds really shitty, just like shagged tappets!!

It as if the ECU is calling for partial or full wastegate closure at idle - but there's not enough vacuum available to do it after being stopped for a while, so it's pulsing with the vacuum pump impulses (vacuum pump is engine driven)

I proved this by unplugging the boost solenoid electric connectors whilst it's 'ticking' (thus prevent any vacuum being sent to the actuators) and it immediately goes completely silent. Also if you unplug the vaccum hoses to the vacuum bottles it goes silent. Under this condition the wastegate will be fully open and thus unable to rattle.

Doing this at old cold start also stops the noises.

[doughboy]

Really bad rattles this morning

Proper jangle / clatter on overrun if you blip the throttle.

Bugger.

[m1bjr]

Ask Terry B if he can work something in the JB4 to reposition them?

You are fighting the BMW 'update' here it seems, where the laters software is supposed to shut them to keep them quiet!

Perhaps you have a small vacuum leak somewhere?

[doughboy]

I've tried the JB3 fix to set 'future use' to 99.

This is supposed to hold the WG's shut at idle, but it makes no difference which might suggest they are unable to close fully at idle??

Could be a vacuum leak as you say - insufficient vacuum to pull them shut at idle, but performance is not affected in anyway i.e. no loss of boost when moving.

Looking at the vacuum lines it seems strange, there are 2 vacuum bottles, 2 solenoids but then the outputs from the solenoids are paralleled up onto the actuators.

So there is no individual control of each turbo. This seems to tie up with the realoem diagram.

http://www.realoem.com/bmw/showparts...75&hg=11&fg=45

The indy I use is shut this week, looks like i need to get in, get the DPs off and get them to set / adjust the actuators, if that fails it'll be back to standard and back in to BMW

[doughboy]

Originally Posted by m1bjr

Ask Terry B if he can work something in the JB4 to reposition them?

You are fighting the BMW 'update' here it seems, where the laters software is supposed to shut them to keep them quiet!

Perhaps you have a small vacuum leak somewhere?

Mine was updated last November ish, so it definitely has new software.

The rattle is the same with the JB3 enabled or disabled or when settings are changed in the JB3 to try and force 100% closure.

Seem the WGs are unable to stay closed 100% at all at fast idle or when warming. When warm it is fine.

The noise is amplified by the DPs, and I can't help but suspect that less back pressure behind the turbine will create a greater pressure drop across it, thus across the wastegate too when closed, even at fast idle the strong exhaust pulses my be enough to 'pop' the gate off its seat momentarily.

[AlanYoro35i]

Mine wasnt that bad, it only happened once so far,, does these get worst over time??

[doughboy]

It seem to be due to wear initially in the actuator linkage and pivot, so that even when fully retracted (100% vacuum) the wastgate is not firmly closed, this allowes it to rattle (more when cold as clearances are larger)

More rattle = more wear = more rattle etc etc it goes on getting worse over time.

Best way is to get the threaded actuator linkages extended to wind out the wear and give firmly closed wastegates with travel still left in the actuators, this needs to be done with a proper (calibrated) vacuum pump at level as would be given by the solenoids. Also by a skilled and experienced tech. (as DW are)

Mines booked in at Darren Wood BMW to have the actuator shafts adjusted properly using vacuum gauge etc.

This means DPs / charge pipes / fan / water pump etc to come off - full days work really, but as mine's modded BMW wouldn't touch it without all DPs off anyway, so I may as well get it done privately. Ouch.

[doughboy]

Had my rattle fixed by Darren Wood BMW - 5 hours work to adjust the wastegate linkages - joy quiet running again!

I've put back the standard downpipes now too. boohoo.

It's so quiet and the turbo lag increase is noticeable AND worse still it does 2 or 3 les MPG with the standard CATs back on.

I was getting 32 ish on steady mway runs, now I can't get over 30.

So CATS make our cars put out MORE CO2 and use more fuel - great.

[m1bjr]

I must be lucky at 70k, Mines pretty quiet.
2006 model too.

[doughboy]

If I hadn't have had deCAT DPs on I wouldn't have noticed the rattling due to the muffling effect of the CATs and the thick walled factory pipes.

So it needs to be a lot worse before you notice it with standard pipes on.

My rattling was fixed with one half turn of the rear turbo wastegate actuator adjuster thread, which is the smallet adjustment available.

The front turbo (the hard one to get to) was spot on. Doh.

This is very interesting as many people on the US forum also report that the rear turbo wears & rattles first - maybe due to hotter running?