Golf GT TDI 150 Engine Knocking / Tapping / Rocking Noise

[djl78]

The car in the video is classic dual mass flywheel failure IF there are no fault codes, the injector balances are moving around in an unusual way and the exhaust fumes have an odd smell to them which is very hard to describe, a sort of oily rather then sooty smell.

Hi Crasher.sorry to dig up an old thread but I am about to embark on a DMF replacement on my 2002 Gt Tdi (ASZ) as it has the classic DMF failure symptoms and wondered if you knew what causes the odd smell from the exhaust?
Thanks

[Crasher]

There could be various reasons for an odd smell such as faulty EGR valve, injector set up error, all sorts, very difficult to say with having a good sniff myself.

[djl78]

Ok. I thought it was something specific to DMF failure as it appeared around the time the DMF started getting noisy. I'll hook up VCDS when it's all back together. Shame you aren't local to me as I'd have gladly booked it in with you.
Thanks

[Crasher]

I have had PD's smell odd when the DMF was causing the idle to be very uneven.

[gear4]

I have a Golf PD 150 02 plate and after reading this thread I think I have the DMF issue. I also have the odd diesel smell. However, today after driving the car for about 17 mins, I still had the tapping noise from the engine and lack of power. So I decided to rev the engine to see if the problem would go away quicker. In doing so, when I released the accelerator, the car carried on with the acceleration noise. I had the clutch pressed down, there was a fair amount of vibration on the gear stick and a stream of white smoke came out of the exhaust. I pulled the car to one side with the clucth down. Then the acceleration noise stopped and the car was back to normal - no tapping noise and the power was back. I was able to drive the car for the next few hours.

If this is a DMF problem then I will get this repaired but if this is a CAM problem then it will cost too much to repair.

[Crasher]

That was diesel runaway and you are lucky it did not go bang! If you want an explanation, just Google "diesel runaway" and you will notice one of the first cars on You Tube is a Golf 4 TDI...... From what you say the turbo has failed and is letting oil into the inlet system and when the air flow becomes high enough, the boost flow lifts up the oil which is ingested and then the engine is running on its own oil. I cannot emphasise this enough, IF it is leaking engine oil into the inlet and it does run away properly, the car will be beyond economic repair so get it looked at and DO NOT drive it, when they go, they are almost impossible to stop.

[gear4]

Thanks Crasher. Is the turbo expensive to repair?

[Crasher]

It depends on how you look at it and how bad it is. If you can do everything yourself then you could do it for as little as £200 if the turbo's compressor and turbine wheels/housings are not damaged and about double that if you need a completely rebuilt unit. The major component is labour and typically we charge around £850 for a standard rebuild all done and including an oil change. However, you have the added complication of oil in the exhaust or even in the inlet and exhaust and this MUST be cleaned out before you drive with the rebuilt turbo. If the oil in the inlet is left it may contain debris and could also cause runaway again plus the smoke will be unbelievable for days. We take everything off and wash all the system out with diluted TFR and then back flush it and blow dry with compressed air. In situation where the exhaust is also full of oil, that has to be removed so it may have to be cut off if it is the original (they often are) and then also filled with TFR and flushed, some I have had to drill a small hole in the silencer, park it on a sloe and let it drain first and then a quick plug weld later! The car in the picture below was a 130PD with the side mounted intercooler and this happened when I disconnected the intercooler inlet pipe. The turbo filled the inlet and exhaust with the entire contents of the sump and it too hours to get clean. Even after draining, removing, flushing and drying the exhaust the smoking to hours of high speed rpm running in the car park to clear. Initially I tried a test drive but soon crawled back to the workshop due to blanketing the area in smoke and getting some justifiably angry looks. To be honest, cleaning the exhaust alone can take longer than changing the turbo. Now we send the cat and silencers away for professional cleaning by a DPF cleaning company which costs around £250.

[colty]

Hi Crasher,

I have sent you a pm as i too have a serious issue with my PD150

[colty]

Did you get to the bottom of this? i've come to the conclusion its the bottom end. i get an intermittent tapping but also a louder knocking under load.