Shifty1962
Well-Known Member
Its not rocket science just years many years of fannying about with various engines trying to get the best out of them without spending a fortune.
The wastegate actuator works on turbo pressure NOT vacuum from the pump.
Yes it should put up a fight when trying to move it by hand. The important thing is that it can move with full travel from closed to open.Sorry for reviving an old thread but my 2003 TD5 auto Disco 2 suffers the occasional 'hiccup' or hesitation under load. Done all the usual stuff - injector harness etc. The wastegate actuator was stuck when I checked but with WD40 and using mole grips on the rod, it has freed up and has a fair amount of travel. But I'm surprised at the amount of effort required to operate the rod - there must be quite a spring it's working against. Is that right? Should I be able to see the rod moving if the engine is revved?
I am writing to share my experience lately.
If you look back, i've had a few threads related to surging/stutter problems.Ive spend a lot of time on this trying to figure out my problems one by one.
I've learned three things:
1) Removing the mid-silencer will reduce the exhaust resistance and may cause your td5 to get a little surging feel. Not big time - but in combination with the two following issues it is amplifying the surging/stutter problem.
2) The CV joints. It's well known I believe? If the splines are worn you will get a surging feel when engaging gears etc.
3) Now this is the most important one. My td5 has a AliveTuning remap, bigger intercooler etc - in general a nice setup. After the remap - the stutter and surging feel was very predominant. The workshop statute it to be a general/different engine problem - amplified by the remap. Trying to solve it - we fitted an new ECU (ouch!), throttle pedal, I exchanged the complete! engine harness myself, the injector harness, the MAf etc. All the usual stuff - expensive though! It was never solved. #1 and #2 helped - but the problem was never solved for real.
The past months I have also wondered if my engine really was providing the bhp/Nm which it should - considering the remap etc. I had this feeling that it was not. But you know - as time goes by you forget the reference point (122 bhp) ...
MOT came up - and I failed big time on the exhaust gas.
Something must have been wrong so I started goggle'ing again. A good friend also led me on the right path. Waste Gate adjustment. The workshop I used for the remap missed out on one very important setup issue - adjusting the waste gate!
I have a Nanocom so I could monitor the inlet manifold pressure.
I decided to start reducing the length of the waste gate rod until the point I hit 'limp-mode' and then extend the rod a bit again.
I took along drive, adjusted the rod a bit, drove again and and adjusted - full turns ..
I was almost crying. By every turn i reduced the length of the rod - the more Grunt I've got. The potential of the td5 was revealed turn by turn. The inlet kpa pressure curve slowly moved down towards the lower rpm and the peak kpa did as well.
I settled at the point where my peak pressure was 230kpa and without going into limp-mode. The turbo pressure at the low rpm is also a lot better. I probably moved the pressure curve down to the lower rpm by 500-700rpm!
The engine runs like a train now!
More important though - the stutter/surging issue has disappeared! So - the problem was really - that the waste gate was open at the low rpm even when the turbo pressure was low. The surging was amplified by the waste gate opening/closing along with the small throttle movements during the jumpy/surging/stuttering physical movement of the vehicle. So by adjusted the waste gate I believe it now runs completely closed at the low rpm and only opens gradually when I reach one bar boost. Anyway - it helped. I might turn it a bit more as i would like to increase my low-end torque a bit more. But I am close to hitting limp-mode.
So - adjusting the waste gate gave me three direct improvements:
1) A lot better low end torque..
2) Much more power..
3) The surging issue disappeared!!
Honestly - I've been sick and tired of my LR and considered to get rid of it.. But now .. I happy again!! BIG TIME!!
Best regards
Lars
(Sorry for my english language/phrasing - I hope you got the point ...)