Turbo failed last night on 1.9 TDI 130 - advice needed please

[pj123]

Hi all,

Wife phoned on her way home from work saying there was a big pop and loss of power on her 52 plate a4 1.9 TDI on 135k. Went to the rescue and sounded like the turbo was making a grinding noise. I'm assuming the bearings have gone so going to remove it and inspect tonight. Disconnected the vacuum pipe to the actuator just so we could drive a short distance home, not ideal i know but it was undriveable, kangarooing above 10mph!

Hoping for some advice on what are common causes. Looks like most people replace the oil feed pipe and clean the return pipe. One advert for a new turbo specifies the oil pick up pipe in the sump should be replaced. I know its common to block on the 1.8T but anyone experience of this blocking on 1.9 TDI's? Looks like a pig to get the sump off the a4 so dont really want to do this unless i have to.

In terms of replacement units I'm tempted to buy a new cartridge all balanced and ready to bolt on the outer parts of the old turbo. Anyone any experience? This would be around £110 versus £250 for a recon unit. Audi would like £943 for a new unit.

Any other tips and advice would be greatly appreciated.
Paul

 

[AlexGSi2000]

Before you attack the sump, it may be worthwhile measuring the flow of oil from the oil feed?
I have no idea on the flow rate on the 1.9TDi's though.

Never used a cartridge replacement, personally I would be more tempted to go for a 2nd hand unit.

 

[Jimmy TDI]

If you have driven the car after it has gone then to be honest you really need to take the sump off to clean all the bits of metal out that will be in there, so you may as we'll change the pick up pipe. Even with the vac line disconnected the turbo would still spool from the exhaust side meaning you could have also damaged the casing. If the casing is damaged you won't be able to use a cartridge in it, but to be honest you would be better getting a recon unit.
As for second hand units, unless you can go and see it in a running car with proof of mileage I would be wary.
Dark side developments do a braided oil feed pipe that is a lot easier to fit than a standard pipe, and cheaper.

 

[Jimmy TDI]

Also ideally you want to take all of the intercooler pipe work, and intercooler itself off to clean the debris out of those also.

 

[pj123]

Thanks for info, I agree recon unit is the lowest risk option. I guess bumper off to get to the intercooler and pipes.

Struggling to find a how to guide for the sump removal. Anyone got any tips on what needs to be removed before getting to the sump - e.g. subframe etc..?

 

[pj123]

So it looks like i came to the wrong conclusion last night. Turbo seems ok, little bit of play in the bearings.

But now i'm really stuck....what is this black box that has blown into two pieces? After the compressor side of the turbo it is tee'd off the air pipe to the intercooler. Should it be one piece or should there be something holding the 2 pieces together?

http://i1113.photobucket.com/albums/k513/p_gliddon/a4%20turbo%20issue/2014-01-07201008.jpg

 

[pj123]

 

[Icarus83]

For reference as it might help, I've just had my turbo replaced as it failed on the 29th Dec; sudden lack of boost followed by howling noise matching the revs. Garage advised oil starvation probable cause (car is on 200k miles) due to blockage in feed, vanes of turbo and shaft very worn and grinding on casing as it wobbled round (tech allowed me to inspect dead turbo). Replacement involved full engine flush, new oil filter and oil, new intercooler as filled with compressor debris, new oil feed pipe and recon turbo. Unfortunately it was not cheap but it has transformed the car. Garage tech recommended to have the car flushed again in 2000 miles to try to remove more debris that might be left. Good luck, Rob

 

[desertstorm]

The box is a Helmholtz resonator, reduces potential noises from the intake system, It will work quite happily without it if you can find some way of blocking the hose that feeds it. I would assume that you have some kind of issue with the boost pressure control as I wouldn't normally expect that part to fail on a standard car.
You need to check the VNT mechanism isn't sticking on the turbo or there isn't an issue with the N75 / Vacuum system.
If a turbo fails you won't get any debris in the sump, possibly some very small particles off the bearing but beyond that nothing.
Replacing the oil feed pipe is a sensible precaution, a standard replacement is fine and easy enough to fit you don't need a braided item from Darkside.
The intercooler does need cleaning out but why anybody would replace an intercooler I am at a loss, No debris is going to find it's way through there, have you ever looked at an intercooler core. They just need reverse flushing to remove oil.

Karl.

 

[pj123]

I have never heard of a Helmholtz resonator so thanks for replying. Any idea how this box is normally held together? If i buy a new one will it be one piece? I guess i could just band this together.

 

[adamss24]

It's fusion welded together and banding it won't work as the pressure will split it apart again ! Go to your local dealer and order another one or look online for 2003 onwards a4 with the 1.9Tdi AWX or AVF engine...

It was a brave move to drive the car with a boost leak, it does the turbo no good !

Just to add my 2 pennys worth, just rebuilding a 1.9Tdi golf Mk4 which munched the turbo, the engine did not run away but alloy particles made it's way into the engine and lodged into nr4 piston, all other 3 are fine ! Took the head off and checked the rods if they bent regardless, no oil made it's way into the pistons, just debris from the compressor !

 

[pj123]

Yeah I agree i shouldn't have driven it. In hindsight the possibility of sucking water in through this massive hole was also potential for disaster too.

For future reference a 'pulsation damper' is £26 from audi part number 8E0 129 955

I have the exhaust disconnected so will be getting some mr muscle in the turbo to clean the vanes later. Then need to work out how to check boost in VCDS.