[ScottJB]

Just picked up an E92 335i and by the looks of it i completely overlooked the biggest issue with the N54.

It felt sluggish on test drive around town tbh but i just put it down to unrealistic performance expectations. No fault codes. However, as soon as i hit the motorway to come home and put the engine under any kind of load it was clear the car was massively underperforming and i got the yellow engine light. Doh!

Read the code, 30FF. Symptoms - feels like no boost at all. Engine light clears after switch off but any kind of sustained load on restart and its right back on. Rattly but i cant decide whether its typical injector noise or wastegate rattle.

No obvious boost pipework loose (although it is a well packed bay so getting eyes on the turbo housings is easier said than done). I've removed the engine cover and the vac lines running from the oil housing area appear fine. Likewise the vac lines to and from the canisters, solenoids *appear* fine. I'm waiting for a vac gauge to turn up to test. The canisters hiss when i remove the lines from the top if that means anything?

Now onto the wastegate bushings. From blind feeling around the rear turbo seems to have a fair amount of slop (in and out), so barring anything ive overlooked in the pipework/vac lines my amateur diagnosis is perhaps its the common issue of the penny valve not sealing properly. But this might be me getting ahead of myself as ive read so much about wastegate rattles this past 48hrs!

If i am anywhere close to correct i guess i need to try to shorten the actuator rod length as per the DIY fix and hope this takes up the slack? Any tips for this, the steering column seems to make access a lot harder on UK cars versus US if the pictures are anything to go by. Am i still best to try to do it from the top blind? Or is access from the bottom any better?

Also anyone anywhere local to me who could take a look (either user or a garage you would recommend as clued up on the issue)?

[NRudy]

I had 30ff codes on my 335i the day after i bought it, it performed well for a while but eventually it did feel sluggish even without codes.

I had turbos replaced as the rattle on startup was really bad.

I also got that code when my camshaft sync sensor coded and it needed camshaft shaftbearing ledges and more or less everything else.

30ff can be caused as a result of various things but id check for leaks initially.
Getting to the turbos to check wastegates is no easy fix.

How i diagnosed mine was, disconnect the vacuum hoses, turn the engine on and rev, put them back on and do it again, if it rattles with them on then doesnt with the hoses disconnected, its wastegates.

[surrey 335i]

There is lots of things it could be, needs a thorough look at.
When you start it from cold does it have a horrible metallic rattle from start up for about 30-60 seconds?
Once the waste-gates get worn the easy way to spot this is from a cold start, but a loud rattle does not normally mean enough slack to cause 30ff fault codes until things get really worn.
let us know what you find.

[Chappers 71]

Check the connection between turbos & charge air manifold, if it's oily get the clamps replaced.

[Theador]

Mine has a metallic rattle for about 30-60 seconds on startup, is this wastegate woes? I got a 30FF code that came back a few times, cleared the codes and now it won't come back. The only thing I can put it down to is 95RON fuel that I put in by mistake when I picked up the car. I've put a full tank of VPower in now and can't get the code to come back.

The car has a HARTGE tune, which is pushing 366bhp.

Originally Posted by surrey 335i

There is lots of things it could be, needs a thorough look at.
When you start it from cold does it have a horrible metallic rattle from start up for about 30-60 seconds?
Once the waste-gates get worn the easy way to spot this is from a cold start, but a loud rattle does not normally mean enough slack to cause 30ff fault codes until things get really worn.
let us know what you find.