Turbo cut out on a 1.9TDI (110) quattro 1997

[Beef]

Hi ,

I've been having this problem for a while now. The turbo cuts when I put the engine under heavy load (accelerating up a hill for example).

If I then stop, switch off the ignition and re-start the problem instantly goes away until the next time I boot it up a hill.

We recently replaced the MAF sensor but this has not changed matters. I am planning to take the turbo off next weekend and give it a good clean out, but can anybody suggest anything else?

I've also run a diagnosis on VAG COM but there were no fault codes.

Any help much appreciated.

Cheers,



Beef

 

[Biglockie]

Sounds like over boost, it may be a problem with your waste gate actuator, it might not be holding boost long enough, if it is it wont show a falut code as its purely mechanically driven.
not sure how to check the actuator. check all your pipes controlling the actuator for splits they might nit be visible straight away so youmight have to bend them to check

A bit from wickipedia below might help

The simplest control for a wastegate is to supply boost pressure directly from the charge air side to the wastegate actuator. A small hose can connect from the turbocharger compressor outlet, charge pipes, or intake manifold to the nipple on the wastegate actuator. The wastegate will open further as the boost pressure pushes against the force of the spring in the wastegate actuator until equilibrium is obtained. More intelligent control can be added by integrating an electronic boost controller.
Standard wastegates have one port for attaching the boost control line from the charge air supply line or boost control solenoid. This is the most common configuration and the only type of configuration found on internal wastegates.

A dual port Tial 44mm wastegate. The side port is the primary port. The top port is the secondary port and not necessary for proper operation.


A dual port wastegate adds a second port on the opposite side of the actuator. Air pressure allowed to enter this second port aids the spring to push harder in the direction of closing the wastegate. This is exactly the opposite of the first port. The ability to help the wastegate remain closed as boost pressure builds can be increased. This also adds further complexity to boost control, requiring more control ports on the solenoid or possibly a complete second boost control system with its own separate solenoid. Use of the second port is not necessary. Secondary ports, unlike primary ports, cannot be simply attached to a boost control line and require electronic control to be useful.

 

[Beef]

Thanks Big Lockie, top response - I'll check all that out.

Many thanks,

Beef

 

[CraigM]

The TDi doesn't have a wastegate - it uses a variable geometry turbo to control the boost.

Have a look at the following link for the most likley causes:

http://forums.tdiclub.com/showthread.php?t=179589

 

[Jimbo.King]

A mate at work had the same problem with his tdi bora (04 plate 150bhp), over a period of time he noticed the power seemed to get less and less until it started going into limp mode under load, then like you he had to turn the ignition off and start again.
He replaced the maf, n75 valve, checked all the pipework with no luck + pulling his hair out, last thing was to check the actuator, these work by suction to pull the actuator arm in to adjust the vanes in the turbo to give you boost, when it was checked with a suction tool there was movement in the actuator arm but not alot, he got a bar and moved the actuator to its full extent and it wouldnt return back, after some penertrating oil on the actuator arm + the turbo arm it freed off, we put it down to either coked up variable vanes in the turbo and the movement freed them up or the actuator was sticking, since doing this he has had no problems in the last 6 months and the car goes like stink again.
Hope this helps

 

[inigoj]

Strange that you had no 'pressure deviation' fault codes.

Have you noticed anything else, like smoke or noises?

As stated above, check the normal 'limp mode' suspects.

sticky variable geometry, vanes + actuator rod & valve, N75 and associated control tubing. (work the actuator rod by hand and ensure it has full range of movement)

Vacuum pump hose connections (especially at bake servo)

Check tubing from top boost hose to remote MAP pressure sensor in ECU + blow through tubing from ECU end. (It traps liquid)

Check/change 2" bit of tubing inside the metal ECU body. (on circuit board MAP)

CAT blockage.

Boost side leak (black smoke)

Check temp readings are in range.

Timing retarded (underfueling) + check injected quantities, timing and fuel temp with vagcom. (+ other related pump problems, loose valve etc)

Tuning box fitted (disconnect battery, remove box, drive around a bit, reconnect box)

 

[ruffrida]

Did you ever solve this as my 2000 plate 1.9tdi does the same thing, i have replaced the turbo, maf and blanked off the EGR, still no joy, but i do have quite a bit of black smoke on start up, and if you drive hard round town, any ideas??

 

[aragorn]

dont think any of those people have been on here in a long time!

Better create a new post with your issues.