engine problems - 2.0TDI

[brummieboy]

Hi all,

I've a 2005 2.0TDI - has been running like a dream until an annual service. Within 70 miles, loss of power whilst driving sedately (no smoke, no ECU light). Diagnosed as a split in the pipe from the turbo to the intercooler.

Within 300 miles of pipe replacement loss of power whilst accelerating (no smoke, no ECU light). New pipe had come off turbo, the clip housing had fractured so pipe wouldn't stay connected. Turbo diagnosed as damaged also - oil coming from air side.

New turbo fitted. Within 70 miles - loss of power whilst driving sedately. OK when engine turned off for 10 mins - lasted another 20 miles. Then loss of power, lumpy engine and ECU light.

3 fault codes:

• glow plug circuit cylinder 3
• turbo pressure regulator - pressure not reached
• MAF sensor.

Pressure coming from exhaust is very low - diagnosed as cat blocked. All checked - no probs. Can see straight through cat. Pressure exiting turbo (without exhaust) is same as from exhaust - low.

car has 3 states of performance;

1. perfect - hasn't been experienced since service
2. what i would call limp mode - very slow acceleration - takes an age to spin up (top speed of about 60mph in 6th), lumpy engine.
3. somewhere in the middle - restricted acceleration but smooth engine. Engine noiser at 3000rpm - like a vibration noise.

Car interchanges between states 2 & 3 without warning. State 3 resets if engine turned off.

A full service has been redone in case faulty part or fluids.

Any ideas would be appreciated........

[brummieboy]

Llatest update. Original situation was probably two separate issues:
1) failure of turbo. Turbo comp say (after inspection) turbo failed due to excessive carbon build up, resulting in worn and sticking bearing causing excessive pressure build up and pipe breaking free and oil bypassing the bearing.

My issue is that the turbo was only 10k old. The previous one had done 85k and was replaced on mis-diagnosis. Comp say turbo not covered by warranty as carbon build up is excluded. This seems unreasonable to me - views would be appreciated.

2) on-going issue that has kept the car off the road now for 5 weeks is low pressure boost not reached. Causes the car to go in to limp mode. Air lines pressure tested - no leaks. N75 valve ok. Engine remapped again. MAF replaced. Thoughts are that the new turbo is not set-up correctly - any other ideas?

I'm loosing the will to live!

[wheely88]

Probably unlikely to be the same issue but 18 months ago I had a brand new turbo installed on my pd150 Leon. It never seemed to accelerate correctly and was like your number 3 mentioned above. Very occasionally it would put itself into limp mode and drive as per your number 2. An ignition reset would give me number 3 again.
Cat was checked (as original turbo failure stuck a lot of oil down it) - but car on rolling road showed it was equally down on power with or without cat. Garage replaced MAP sensor and removed/cleaned the recirculation valve (cant remembe its name). I also did vacuum checks and found full vacuum going to actuator on turbo (which controls variable boost inlet vein). Eventually the garage agreed to re-replace the turbo --- and if it didnt sort the issue we would discuss costs. However when they removed the turbo they found the top of the actuator (where the vac line connects to) was slightly distorted on one side (as though it had been dropped on it, or sucked itself in somehow). This was reducing the throw of the actuator so the inlet vein was never reaching full boost position and I was around 20%+ down on power. new turbo fitted and full boost returned -- all under warranty.

Does sound somewhat similar issue (the limp mode is that the expected boost and the MAP boost were just too far apart and thus engine management goes into safe mode, allowing no boost at all and limiting revs to about 3K max).

Hope this may be of some use. I used to have a picture of faulty actuator but I've deleted it as a nightmare best forgotten..... until now

Mark

[simy625]

have u had a look at your egr valve?they have a habit of collapsing on the inside and basically staying open constantly.this will be noticed on acceleration as the there isnt as much fresh air getting into the engine as it wants.it also causes MAF sensor faults and turbo faults to be stored in the fault memory.

[bloostar]

Have you checked for oil around the fuel filter hoses? Ifso it could be the entire intercooler causing the problem. Similar thing happened to me last November and had to get the thing replaced under warranty. Since had to replace all the filters and an 'ultrasonic bath' on the injectors due to them being gunged up with oil. Works greatsince the replacement.