The classical 30FF turbocharger charge air pressure too low..any ideas?

[pbondar]

Background…

Major upgrade..TTE500 turbos, 535 LPFP, VSRF inlets and charge pipe, decat down pipes, Fox cross over and exhausts, VTT turbo outlets, Forge DVs, Wagner 7.5” FMIC..stock air back with Pipercross filter, NGK stage 1 colder 22 thou, Index 12 injectors..

All was going so well, a few hundred miles, several runs on the dyno circa 20 psi boost 500 BHP , 680 nm torque on 98 Ron fuel..chasing a misfire on cylinder no 6 at 6,200 ish…

Tuner asked to change plugs n coils to check if that affected misfire on cyl 6, swapped 1 and 6 coils and fitted colder NGK at 22 thou..went out no change, strong pull with 1 out of 6 with cylinder 6 misfires.

Tuner asked for cylinder 6 injector to be checked..duly checked..no observable issues, fresh seal and decoupler fitted..

Went out and before reaching the ‘pull zone’ bong and the half dead engine symbol lit up..a code check showed the 30FF code..

I went ahead and did the pulls..

So here’s some earlier logs with no errors apart from the oEd misfire on cylinder 6 at 6k rpm…

11th iteration to to correct misfire

Data logging went wrong ..only one log..will re-do.. swapped coils 6 and 1, fitted NGK colder plugs at 22 thou.. First run misfired on 6 again! However next 5 pulls no misfire…weird..will redo runs..

www.spoolstreet.com

and here are the logs with boost impaired..

Real sudden loss of boost ignore earlier post

Any ideas along with 30FF fault code

www.spoolstreet.com

So it’s getting some boost around 6 psi not 21 psi..

I started to do some vacuum tests which showed a leakage fault on the rear boost controller ..I swapped it out for a new Pierburg..no change.

I took it to my tame Indy / dyno guys..they confirm no obvious loose connections anywhere in the inlets, turbos, intercooler and charge pipe..

So it’s work in progress due to availability of people and resources..I realise that we’ve not done a fully comprehensive set of tests..

Any views on where to look would be appreciated…so no error on start up or under modest throttle…which I understands tends to preclude boost leaks..

RSVP

 

[wheela]

So it’s getting some boost around 6 psi not 21 psi..

I started to do some vacuum tests which showed a leakage fault on the rear boost controller ..I swapped it out for a new Pierburg..no change.

I took it to my tame Indy / dyno guys..they confirm no obvious loose connections anywhere in the inlets, turbos, intercooler and charge pipe..

Did they do an actual boost leak or smoke test, or just a visual of the connections?

 

[pbondar]

Did they do an actual boost leak or smoke test, or just a visual of the connections?

So far just a physical examination..as I said due to time constraints a full exam has yet to take place..the question is why does a N54 perform very well..then drive a further 5 miles at modest speed..go into my garage for a few days while I remove and reinstall an injector then after that 5 miles later gently driven develop this fault ?

 

[Torgus]

Pressure test the intake track for a leak. That is likely your issue.

 

[pbondar]

Pressure test the intake track for a leak. That is likely your issue.

Do you mean the turbo outlets to intercooler to charge pipe ?

 

[Torgus]

Do you mean the turbo outlets to intercooler to charge pipe ?

google/you tube: how to pressure leak test 335i n54

 

[pbondar]

google/you tube: how to pressure leak test 335i n54

will get some kit and advise ..thnx

 

[pbondar]

Well boys and girls having gone down the vacuum testing route and found a rear boost controller that was leaking I thought I’d solved matters…sadly no..

Following advice here and frustration with Indy’s inability to troubleshoot the issue ordered a leakage kit..

Within 10 seconds of using it found the issue…

The hose connecting the rear and front turbo outlet pipes (VTT) had popped off the front aluminium pipe…turns out the Indy who fitted it had not put enough rubber on the front outlet so it had just slipped off..

Of course it was hidden by a heat shield hence why we didn’t ‘see’ it earlier…

Clamps fitted from underneath so couldn’t get to release the clamp that was working…

Dremels are wonderful things..

Cut the remosimg tight clamp off…rotated hose to get the front clamp…found a spare wider clamp in my goody box…refitted..

Waiting for some fresh heat shield wrap then will test..got to be an improvement..

 

[Torgus]

Always nice having to troubleshoot and then fix someone else's mistake. Glad you got it fixed. The pressure leak test is useful to have on hand for anyone.

If it does not stay on I would use the hairspray trick, replace the silicone coupler, and switch to murray clamps.

 

[pbondar]

Always nice having to troubleshoot and then fix someone else's mistake. Glad you got it fixed. The pressure leak test is useful to have on hand for anyone.

If it does not stay on I would use the hairspray trick, replace the silicone coupler, and switch to murray clamps.

It’s another example of tackling the unknown…once you‘ve done it for the first time you wonder why you ever dithered..

 

[BMWDIYer]

Which part are you referring above in your pictures? Is it #1 below? This is N54 E92 335i. Thanks!

 

[pbondar]

Yes it’s 1 in the diagram but it’s the VTT version of it..