twin turbo

Post Reply
rjb1z4
Newbie
Newbie
Posts: 1
Joined: Tue Jul 24, 2018 5:24 pm

twin turbo

Post by rjb1z4 » Tue Jul 24, 2018 5:32 pm

can any 1 help
i thought that the rattle i was getting was a loose heat sheild on the exhaust but my mec tells me its one of the turbo's
and it would be wiser to replace the 2 of them
im told it's quite a common problem
please advise

User avatar
RustyZ4
Lifer
Lifer
Posts: 3272
Joined: Fri Dec 14, 2007 7:23 pm
Location: Maidstone, Kent

twin turbo

Post by RustyZ4 » Tue Jul 24, 2018 5:39 pm

I didn't think it was that common, unless of course you have done mega miles and really pushed it, personally I would get a second opinion
Z4 Mineral Grey, 28i MSport Auto, lots of goodies
Z4 E85 3.0, gone but now with son :D
Growing Old is Mandatory But Growing Up is Optional

User avatar
Silverzedtom
Senior Member
Senior Member
Posts: 1133
Joined: Sun Jan 15, 2017 8:19 pm
Location: Crowborough, East Sussex

twin turbo

Post by Silverzedtom » Tue Jul 24, 2018 6:55 pm

100% get a second opinion. I’m not sure many turbo failures have been noted on here :tumbleweed:
2.5Si sport titan | Syrah blue interior | CSL reps | ZHP gear knob | Eibach pro kit springs | CDV delete | Wiechers racingline strut brace | Ram air scoop | Matt grill | Blue Calipers | de-badged | muffler delete | K&N | CF skirt extensions | Stubby

Online
User avatar
Smartbear
Lifer
Lifer
Posts: 7586
Joined: Wed Feb 05, 2014 6:54 pm
Location: In a barn

twin turbo

Post by Smartbear » Tue Jul 24, 2018 7:09 pm

rjb1z4 wrote:
Tue Jul 24, 2018 5:32 pm
can any 1 help
i thought that the rattle i was getting was a loose heat sheild on the exhaust but my mec tells me its one of the turbo's
and it would be wiser to replace the 2 of them
im told it's quite a common problem
please advise
I’ve heard of earlier 35i/35is cars suffering from wastgate rattle, I don’t think it affected the performance/function of the turbo but was just an annoying sound :x
Rob
Image

e89 Sdrive2.0 20i, plenty of mumbo & good economy-the thinking bears z4 :P
e89 Sdrive30i this ones busted, pass me another...
e85 3.0si, i foolishly sold my trouble free car...

User avatar
buzyg
Lifer
Lifer
Posts: 12950
Joined: Fri May 20, 2011 6:11 pm
Location: Cornwall

twin turbo

Post by buzyg » Tue Jul 24, 2018 8:30 pm

I have never had a twin turbo. However I have had three fail on my previous fiat. Never heard any kind of rattle. The things spin at such high speed they go bang before there go rattle. Plus that is generally accompanied by oily smoke out of the exhaust. Agree that you should get a second opinion.
Image

User avatar
R.E92
Member
Member
Posts: 774
Joined: Wed Dec 04, 2013 10:10 am

twin turbo

Post by R.E92 » Wed Jul 25, 2018 8:42 am

Very common issue on all N54 engined cars. Infact so common I'd say it's just normal!

The wastegates start to rattle from 40k onwards. BMW made the problem less obvious with a software mod back in 2008 but you still hear it when in enclosed areas like garages and multi-storey car parks.

The rattling can be caused by leaking vacuum pipes so my first action would be to replace all of them. Just google "n54 replace vacuum lines DIY" and follow those threads, it's a 1 hour DIY at most.

You could also try doing the "Mr.5" fix. Google "Mr.5's wastegate rattle fix" and follow the instructions in that thread.

If neither things help then you can refurb the turbos with some new wastegates or just put some new pure turbos and enjoy some extra power :driving:

Maniac
Lifer
Lifer
Posts: 8132
Joined: Tue Oct 26, 2010 2:52 pm

twin turbo

Post by Maniac » Sat Jul 28, 2018 7:57 am

Mine has done this since new. Only when cold.

Had it back many times and the software update does help reduce the noise at the expense of notable turbo lag. (I didn’t realise how much lag until I coded my engine to remove it recently)

Lazza
Member
Member
Posts: 266
Joined: Sat Nov 11, 2017 10:42 am
Location: Wokingham

twin turbo

Post by Lazza » Mon Jul 30, 2018 11:04 pm

Mine sometimes has a rattle like that but it’s the exhaust flap. Try disconnecting the vacuum tube from the actuator and see if the noise goes away.
Z4 S-Drive 35i
Audi TT S-line
Mazda MX5 Mk2.5 (for sale)
Wokingham Berkshire

Online
User avatar
GuidoK
Senior Member
Senior Member
Posts: 2600
Joined: Tue Aug 17, 2010 1:37 am

twin turbo

Post by GuidoK » Mon Jul 30, 2018 11:38 pm

The classic 'wastegate rattle' on the n54 turbo's is a clearance matter on the guide bushings of the wastegate pins (so the bushings that go into the turbo housing where through the wastegate actuator rod goes).
The wastegate rattle can cause the wastegate to seal imporpely, causing loss of power, bad gas mileage and engine codes.

There are kits for this to repair this but fitting this is definately a specialist job (specialist as in turbo specialist, not a normal auto mechanic).
The bushing has to be drilled and hammered out an a new one has to be pressed in (including fitting new valve, lever etc). So thats quite a job. (just getting the turbo's out is quite a job, modifying even more, but it beats having to buy £3000 in bmw parts)

Repair kit: https://www.ecstuning.com/b-vargas-turb ... 4-wf2~vtt/

More on the rattle and worn bushings:




So I hope you dont have this.
Z4 3.0i | ESS TS2+ | Quaife ATB LSD | Brembo/BMW performance BBK front/rear | Schrick FI cams | Schmiedmann headers+cats | fully polybushed | Vibra-technics engine mounts | H&R anti rollbars | KW V3 coilovers | Sachs Race Engineering clutch

Post Reply