1996 E39 525TDS Torque problem

[georgedevries]

Hello fellow BMW drivers,

I'd like to post a problem on my '96 525TDS.
Just recently, when driving away, the engine's power/torque seems to be 'gone', I have no power at all and it seems ages just to get to 60 Km/h!
The car has been serviced recently and has been changed filters and oil...

The problem started 2 days ago, when driving away with a cold engine, but then seemed to resolve itself when the engine was warmed up...
Today I'd have the same problem, but this time when I took of with a cold engine everything was fine. After having turned off the engine for several minutes while checking the tire pressure, I'd get in and start the car to be having the torque problem again!?
I'd go to a mechanic and he'd read out the car but it doesn't seem to have any electronical malfunction.

Does anyone have a suggestion or experienced similar problems?

Regards,
George de Vries
1996 BMW 525TDS owner

[marti5]

Hmmm could be, don't quote me though, your turbo is playing up ? I have a diesel van an the turbo went on that and I lost nearly half my power and it would some times cut in on occasions after a starting either at the beginning of the day or the end , that's what I would get checked 1st.

[MADDOUG]

The in tank lift pump may be playing up and that causes the injector pump to struggle for fuel,it creates a vacuum using the fuel it has and this draws fresh in but not enough,this will not flag a code or light.Number 4 injector has a needle lift sensor built into it,the ecu uses the info from it to cross reference timing data to ensure correct advance retard running of the injector pump/should give a light and a code.There are a couple of temp sensors under inlet manifold,one for dash gauge and one for ecu,now you may notice when engine is started from cold that performance ain't to great,its widely assumed that ecu does not let engine have full power until it is slightly warm/or to protect auto box,if you let warm up for a few minutes before driving you rarely notice this,the temp sensor for this may be dodgy.The lift pump again,,,the fuel filter has a pressure sensor built into it so lack of fuel pressure may cause the fault.the lift pump will run on cold starts when glowplugs on/it does not run when starting a hot engine and when engine hot and running the ecu switches it off and on as it see's fit.You have a boost pressure sensor that is mounted near fuel filter,the pipe for this goes to the inlet manifold just above the rear of injector pump.And lastly and this may be the most likely cause,,,the egr valve may be stuck open,most owners remove the pipe which the exhaust gas travels down to where it bolts up to the inlet manifold (two 13mm bolts) pull it off a bit and put a new (made of steel) 2p bit in there which seals it off,an easy fix that takes around ten minutes.One major symptom of egr that sticks is car is gutless until pushed hard,then the turbo pressure overcomes the exhaust gas pressure and around 4k revs the car starts to come alive again.Because your fault is off and on the egr is the likely cause.