Turbo cutting out after 10 minutes

[leerees]

Hi,

I'm wondering if anyone can help diagnose the problem with my turbo. My car is an 02 plate A4 B6 with a 1.9 130 bhp TDI.

1) After about 10 minutes the turbo stops working and makes no noise at all. The car has a loss of power but after 3000rpm there is still some power

2) after about 15 - 20 minutes the car looses even more power and is painfully slow regardless of RPM.

Turning the engine on and off will restore some power however to get the turbo to work again I have to leave the car for a few hours.

When the turbo is working I noticed that there is a slight scraping noise as the car decelerates / turbo spins down. It has always made this noise for the last 20,000 miles.

I'm wondering what could be the problem here, do I need a new turbo or is there a cheaper fix?

[PreciseD]

Maybe your wastegate is sticking once the turbo heats up. Check the actuator and linkage and make sure it's functioning with no binding.

[customa4]

Hi,

I'm wondering if anyone can help diagnose the problem with my turbo. My car is an 02 plate A4 B6 with a 1.9 130 bhp TDI.

1) After about 10 minutes the turbo stops working and makes no noise at all. The car has a loss of power but after 3000rpm there is still some power

2) after about 15 - 20 minutes the car looses even more power and is painfully slow regardless of RPM.

Turning the engine on and off will restore some power however to get the turbo to work again I have to leave the car for a few hours.

When the turbo is working I noticed that there is a slight scraping noise as the car decelerates / turbo spins down. It has always made this noise for the last 20,000 miles.

I'm wondering what could be the problem here, do I need a new turbo or is there a cheaper fix?

I had similar symptoms with my 1.8 and it turned out to be a clogged cat. Here's the thread where I was trying to figure out what was going on. Click

[leerees]

Thanks for the replies guys,

I'm going to take it into the garage on Friday, the guy is going to get the diagnostic codes and have a look at the wastegate and other common faults and will only charge me £25 so that seems pretty reasonable to me. I'll post up his findings here. Fingers crossed it's something simple.

[leerees]

I just had the Audi back from the garage, he said there's quite a bit of oil running around the system

He found fault code P1557 - charge pressure control positive deviation.

He replaces vac pipe to waste gate actuator, he suspects boost presssure control solenoid faulty, recommends new vac pipes + intercoolore hose seals + cleanout egr valve.

Now I was quote nearlly £300 to do all this work and there is still no gaurantee that it will fix the fault.

right now the car just feels really stuffy and choked, even whilst the turbo is working.

I have found a youtube video which is a simple fix using mr muscle, it's for an A3 but I presume it's the same deal:

https://www.youtube.com/watch?v=PbUAfzi5BdM

I've also found another video which may be relevant.

https://www.youtube.com/watch?v=Zg9gVCKljEI

[customa4]

Sounds like your car might be in limp mode. You need to do a boost pressure test to find out if there's any leaks. I'm not really familiar with your engine but you might also want to check if the N75 is faulty.

http://wiki.ross-tech.com/wiki/index...5/P1557/005463

[leerees]

Car definitely goes into limp mode after about 5 minutes due to overboost. p1557 error code.

I'm going to try and clean the egr and spray mr muscle into the hot side of the turbo.

I'm a total newbie and don't really have any idea what I'm actually doing, just searching the net now to find a picture of the egr location on the A4 B6

[johnwiz]

Edit, just read that it is for a TDI engine. Deleting my comment as my issue was with the 1.8T engine.

[blownb6]

My friend had same issue with mk4 tdi same engine. It was the waste gate sticking do to carbon build up from the egr system. He had it all cleaned worked well for a bit, he was givin a suggestion to replace turbo bc the waste gates on tdi turbos are different then k03 and there was no proper way of cleaning /fixing


Googke tdi alh turbo wastegate to see what i am talking about

[leerees]

I've cleaned out the EGR and the body inside there now moves freely. I've spray mr muscle into the rusty pipe from the underside of the engine that goes into the turbo, i did try to take the exhaust off but couldn't get the nuts undone.

When I started it up loads of black smoke came out.

The turbo now makes the whoosing sound like it used to although it still sticks, it's more of an intermitent issue now and the car seems a lot faster but it's still not perfect. I'm wondering if its anything to do with that actuator rod, that still feels really stiff to move.

Should the actuator be really easy to move or stiff? Would smothering it with WD40 help?

I've looked up wastegate actuator, is that the same thing as the VNT actuator rod that's kind of underneith and hard to reach? Is the wastegate actuator easy to change?

One thing I'm convinced of is that the turbo it'sself is fine as it whooses up nicely and when it's working there is plenty of power there, maybe not as much as when I first brought the car but still very good.

This is all so frustrating, I'm just glad I never paid the garage to do this.

Also one other thing, if I take the big air pipe off, could I not just poke a straw through the vanes and spray mr muscle there, i haven't done this as I read that this part of the turbo is aluminium and the mr muscle will damage it, any help would be appreciated.

[blownb6]

I've cleaned out the EGR and the body inside there now moves freely. I've spray mr muscle into the rusty pipe from the underside of the engine that goes into the turbo, i did try to take the exhaust off but couldn't get the nuts undone.

When I started it up loads of black smoke came out.

The turbo now makes the whoosing sound like it used to although it still sticks, it's more of an intermitent issue now and the car seems a lot faster but it's still not perfect. I'm wondering if its anything to do with that actuator rod, that still feels really stiff to move.

Should the actuator be really easy to move or stiff? Would smothering it with WD40 help?

I've looked up wastegate actuator, is that the same thing as the VNT actuator rod that's kind of underneith and hard to reach? Is the wastegate actuator easy to change?

One thing I'm convinced of is that the turbo it'sself is fine as it whooses up nicely and when it's working there is plenty of power there, maybe not as much as when I first brought the car but still very good.

This is all so frustrating, I'm just glad I never paid the garage to do this.

Also one other thing, if I take the big air pipe off, could I not just poke a straw through the vanes and spray mr muscle there, i haven't done this as I read that this part of the turbo is aluminium and the mr muscle will damage it, any help would be appreciated.

i am telling you the turbo is not good and that ur issue to everything,

here is the video i was talking about

[leerees]

I Google tdi alh turbo wastegate and the first thing that came up was an eBay store selling a tdi alh turbo wastegate for £37. If this can be fixed then I'm not going to spend all that money on a new turbo.

[leerees]

ok so I've now changed the hoses, cleaned out the EGR, I also redone the mr muscle trick and the vnt actuator rod is moving freely. However, I still get the same problem, perfect performance from cold and then limp mode after around 10 minutes.

Does anybody have any ideas what else I could do?

[leerees]

Just changed the n75 and still having same probs

[leerees]

i am telling you the turbo is not good and that ur issue to everything,

here is the video i was talking about

When you say turbo is not good do you mean it needs replacing? You mentioned the wastegate actuator being shot but mine is fine, it moves freely. I'm worried that if I replace the turbo it's not going to clear the fault.

[PreciseD]

When you say turbo is not good do you mean it needs replacing? You mentioned the wastegate actuator being shot but mine is fine, it moves freely. I'm worried that if I replace the turbo it's not going to clear the fault.

What do you mean it moves freely? If you can move the actuator by hand while its hooked up then you have a problem. If when applying vacuum to the actuator and it moves then its good.

[leerees]

By it moves feely I mean there is a bit of resistence but no scraping. Before I did the Mr muscle trick you could feel scraping and the actuator was almost impossible to move.

I'm now going to take the turbo off and dismantle it as I've found a cleaning guide on then net.

The main issue I have now is getting the right tools. I have spanners and ratchets but the bolts seem impossible to reach. Also I can't get the bolts undone from the hot side to the exhaust. I've ordered a a reciprocating saw off eBay so will attempt to cut them off.

If anyone had a turbo removal guide I'd be highly appreciative :-)

[leerees]

Hi Guys,

Just a quick update, I ended up getting a new turbo for the car although that didn't cure the problem.

After spending a lot of money (over £1000) on garage fee's and parts I found an Audi specialist in Cornwall (UK) called A.V.S who said they could diagnose and repair my car. This will be the 5th garage I had taken it too.

I took it to A.V.S and within an hour they had fixed the problem, a faulty boost pressure sensor and the pricing for the fix was very reasonable. I have just learnt the difference between all those technicians and a real mechanic.

I hope others reading this can save themselves some money by checking the boost pressure sensor first.

By the way if anyone wants to buy my old turbo feel free to reply here, it's done a few miles but no reason why it can't be refurbed and resold.

[USAF Long]

wow.. glad it's finally fixed... but poor headache and wallet.