Dhawk12
Veteran Member
I have a 2000 Jetta TDI (ALH) 5 spd that I just bought and I am starting to worry that it has an impending turbo failure.
Symptoms: Whine that sounds a little like a police siren when holding RPMs around 2000 RPM. If you give it a tiny bit of the go pedal (think feathering the pedal) it will change pitch up or down, but the noise dissapears under full throttle (either it is masked by the rest of the engine noise or it doesn't get louder). I have had others in the car who either can't hear it or when they do, they tell me it is just the sound of the turbo (the problem being I have a 2002 Golf TDI that doesn't do it, hence why I noticed it on this car.)
I have also removed both the downpipe and output side of the turbo and the shaft doesn't seem to be touching the sides (radial play) but it does move in and out a bit (axial play) on both sides. It barely moves enough to be measurable visually but you can feel it going in and out with your hand. I understand from other forums that spec play is between .001" and .004" (axial play) but I don't have a dial guage to measure it. The blades of both impellers look fine from what I saw.
I thought it may have been an exhaust leak that was causing the sound (another user had a cracked flex pipe that caused a similar issue) but I have been unable to find any leaks with the car idling. It could possibly still be a leak on the intake side of the turbo, but short of making sure all the joints are connected I don't know how to test that.
I have been keeping an eye on oil consumption and it doesn't seem to be going through much if any. There is no significant oil buildup in the intercooler or the the output hose from the turbo. The only place that seemed to have more oil than it should was the input hose on the intake side of the turbo coming from the airbox. The small amount of oil it might be using could be from a minor leak at the vacuum pump as well as what seems to be the back of the valve cover.
Other than the sound (and possible excess axial play) it would seem it is healthy. I just really don't want to just forget about it and have the turbo dump oil into the intake. (In the mean time I have verified that my ASV is working in the event of a runaway.)
Any suggestions?
Symptoms: Whine that sounds a little like a police siren when holding RPMs around 2000 RPM. If you give it a tiny bit of the go pedal (think feathering the pedal) it will change pitch up or down, but the noise dissapears under full throttle (either it is masked by the rest of the engine noise or it doesn't get louder). I have had others in the car who either can't hear it or when they do, they tell me it is just the sound of the turbo (the problem being I have a 2002 Golf TDI that doesn't do it, hence why I noticed it on this car.)
I have also removed both the downpipe and output side of the turbo and the shaft doesn't seem to be touching the sides (radial play) but it does move in and out a bit (axial play) on both sides. It barely moves enough to be measurable visually but you can feel it going in and out with your hand. I understand from other forums that spec play is between .001" and .004" (axial play) but I don't have a dial guage to measure it. The blades of both impellers look fine from what I saw.
I thought it may have been an exhaust leak that was causing the sound (another user had a cracked flex pipe that caused a similar issue) but I have been unable to find any leaks with the car idling. It could possibly still be a leak on the intake side of the turbo, but short of making sure all the joints are connected I don't know how to test that.
I have been keeping an eye on oil consumption and it doesn't seem to be going through much if any. There is no significant oil buildup in the intercooler or the the output hose from the turbo. The only place that seemed to have more oil than it should was the input hose on the intake side of the turbo coming from the airbox. The small amount of oil it might be using could be from a minor leak at the vacuum pump as well as what seems to be the back of the valve cover.
Other than the sound (and possible excess axial play) it would seem it is healthy. I just really don't want to just forget about it and have the turbo dump oil into the intake. (In the mean time I have verified that my ASV is working in the event of a runaway.)
Any suggestions?