Battlebus performance, thankyou Marks DTM Calib

[Marks DTM Calib]

Is the air filter ok? Exhaust not blocked? Vac all ok

[JamesV6CDX]

Does this have a VNT setup?

[Marks DTM Calib]

No, standard waste gate system.

For me, we know the inlet is clear now and it revs up to the red line which was not previously possible.

So now its a case of why its the turbo struggling to boost (turbo is know good), this usually means air starvation, vacuum fault so the waste gate is not closing, restricted exhaust so the turbo cant spool up or the EGR is open (it does not appear to be but it would be interesting to compare the one fitted with a second one to see if the sprung force on the plunger is the same).

[TheBoy]

How can I tell if exhaust is blocked?  I'll go out and check air filter at lunchtime, as it's probably still the one I put on shortly after I got it.


Following the intake clean last week, and the wastegate actuator being freed off yesterday, its "good enough" for now.

I *really* need the car next week, so bit reluctant to touch it for a couple of weeks, for fear of making it worse.  So this saga may continue again in a couple of weeks

[TheBoy]

Vac all ok

There are, contrary to what I said, Tech2 tests, and both the swirl flaps and wastegate actuators move (fully, as far as I can tell) at idle.  Unable to test EGR one, as no visible movement, but VXL V6 did give me a spare EGR, so might pull mine out at lunchtime, and compare spring strength to VXL's one.


Is it possible the wastegate actuator arm needs adjustment?  The other thing that crossed my mind, is would the wastegate start to clog up enough that it wouldn't close fully, thus not fully spooling turbo?

[tunnie]

I still do have a little chuckle at the person who loves RWD and 'POWEEERRR', after years of pi$$ taking of my 2.2. Now has a diesel powered, FWD, 7 seater mummy bus 

[TheBoy]

I still do have a little chuckle at the person who loves RWD and 'POWEEERRR', after years of pi$$ taking of my 2.2. Now has a diesel powered, FWD, 7 seater mummy bus 

Its only used when I have to do my bit for the old'uns.  I'm not allowed to drive properly with old people, as old people's bladders are always as strong as younger ones.

I should have bought a petrol one in hindsight. Ho hum.

[Marks DTM Calib]

Vac all ok

There are, contrary to what I said, Tech2 tests, and both the swirl flaps and wastegate actuators move (fully, as far as I can tell) at idle.  Unable to test EGR one, as no visible movement, but VXL V6 did give me a spare EGR, so might pull mine out at lunchtime, and compare spring strength to VXL's one.


Is it possible the wastegate actuator arm needs adjustment?  The other thing that crossed my mind, is would the wastegate start to clog up enough that it wouldn't close fully, thus not fully spooling turbo?

You won't find that much gunk in the exhaust side generally as it runs hot and tends just to be carbon and not a carbon/oil mist mix.

[Marks DTM Calib]

How can I tell if exhaust is blocked?  I'll go out and check air filter at lunchtime, as it's probably still the one I put on shortly after I got it.


Following the intake clean last week, and the wastegate actuator being freed off yesterday, its "good enough" for now.

I *really* need the car next week, so bit reluctant to touch it for a couple of weeks, for fear of making it worse.  So this saga may continue again in a couple of weeks

Easy way to check is exhaust is to disconnect the front pipe to join and see if the turbo achieves required boost pressure.

[Marks DTM Calib]

Other simple thing to try (but go easy) is to connect vac directly to the waste gate actuator....and see if it overboosts.

[TheBoy]

Not too bad, but could be better.

Hoovered most of the stuff off, and turned it 180 degrees

[Marks DTM Calib]

I forgot to add, actuator setting is dead easy on these, simply remove the retaining clip from the actuator arm and fully close the waste gate, the actuator arm should just slide over the waste gat connection and apply a slight sprung load.

[Nick W]

That was what a quick peek in the inlet of my GDI Legnum revealed, when it began to idle unreliably. That was the result of early direct petrol injection and lots of EGR. Power loss was unnoticable, because it had none to start with. When I added up the cost of sorting it, a rebuilt throttle body, and new suspension to about £1500, I sold the car for the £300 I had paid for it a year earlier.

[Andy H]

Where is the MAP sensor on these?

VWs used to have a rubber hose between inlet manifold and MAP sensor (when it was located in the ECU). The rubber hose is prone to blocking which screws up the boost reading.

Later ones have a MAP sensor on the pipe between the intercooler and the inlet manifold but this can still get blocked and give wrong (or sluggish readings)

[TheBoy]

MAP is bolted directly to intake on these.

I have tried another MAP, just in case


Also swapped over EGR at lunchtime, though the replacement (thanks again VXL V6) felt the same stiffness as original. No difference on Tech2 readings. Will 'give it some large' on the way to work tomorrow to see if any difference - not expecting any.