Audi A3 2004 - Loss of power in high gears (help please!)

MrMarvelous · 17 May 2018 at 19:25

I'm assuming the turbo on my A3 TDI is clogged up to the hilt with soot or about do kick the bucket. Started happening a few days ago whilst travelling on the dual carriageway/motorway. Basically as soon as I reach 75+ MPH the power just goes. I think it's also to do with higher RPM but i'm not sure.

Before taking it to the garage i'd like to have a go at cleaning it but I can't for the life of me find a way to get to the turbo. I've scoured the internet high and low and can't find any tutorial pictures or videos so any help here would be greatly appreciated.

I've had a look at this video and want to give the following a try:

Gaijin · 18 May 2018 at 09:11

#notsureifsrs

This seems to be a very bad idea.

Using household cleaner on a device that spins up to 150,000rpm? No thanks. Get it looked at properly or you may well be shopping for a new turbo/engine.

Armageus · 18 May 2018 at 09:27

A quick google reveals it is apparently a thing, however can't say I'd be too comfortable taking a caustic chemical to any delicate engineering (indeed there seem to be a few horror stories mixed in with the "success" stories).

If you want to try and DIY it before taking to a garage, I'd be looking at:
https://www.amazon.co.uk/Forte-Diesel-Turbo-Cleaner-400ml/dp/B009E5UJM6

or the twin pack with diesel treatment:
https://www.amazon.co.uk/Forte-Advanced-Diesel-Treatment-Cleaner/dp/B00EN00NZA

Which seems to be one of the better recommended Diesel cleaners, when used in conjunction with a good "italian tune up"

IAmATeaf · 18 May 2018 at 13:28

Wouldn’t doing this also interfere/remove any lubricants? Are there any lubricants within the turbo? I’ve no idea but for something that spins at very high speed I personally would not be doing this.

Armageus · 18 May 2018 at 13:34

IAmATeaf said:
Wouldn’t doing this also interfere/remove any lubricants? Are there any lubricants within the turbo? I’ve no idea but for something that spins at very high speed I personally would not be doing this.

The turbo bearings are lubricated with oil from the engine.

The "deposits" that may need removing are within the exhaust gas side of the turbo (which the forte cleaner removes through chemicals which remain unburnt from the fuel).

GinG · 18 May 2018 at 13:46

It could well be your fuel filter.

Had the same thing happen in my A4 2.0TDI...changed the fuel filter and worked fine.

The fuel filter hadn't been changed in ages and when it came out it was black...I was told at the higher revs it would be starving the engine and sapping power.

Nasher · 18 May 2018 at 13:51

I wouldn't risk that. You don't know how these chemicals will react with the metals and other components (especially seals). Use proper stuff.

MrMarvelous · 18 May 2018 at 14:00

Armageus said:
A quick google reveals it is apparently a thing, however can't say I'd be too comfortable taking a caustic chemical to any delicate engineering (indeed there seem to be a few horror stories mixed in with the "success" stories).

If you want to try and DIY it before taking to a garage, I'd be looking at:
https://www.amazon.co.uk/Forte-Diesel-Turbo-Cleaner-400ml/dp/B009E5UJM6

or the twin pack with diesel treatment:
https://www.amazon.co.uk/Forte-Advanced-Diesel-Treatment-Cleaner/dp/B00EN00NZA

Which seems to be one of the better recommended Diesel cleaners, when used in conjunction with a good "italian tune up"

Trying to look for the above to buy from me locally (Derbyshire) and can't find any stockists. Is the only way to buy the Forte stuff online? Looks like even a few of the Halfords around me don't stock it.

GinG said:
It could well be your fuel filter.

Had the same thing happen in my A4 2.0TDI...changed the fuel filter and worked fine.

The fuel filter hadn't been changed in ages and when it came out it was black...I was told at the higher revs it would be starving the engine and sapping power.

Will give this a shot. Anywhere where I can find it to pick up? Again, Halfords don't seem to have it.

Thanks for the help also guys.

Armageus · 18 May 2018 at 14:02

MrMarvelous said:
Trying to look for the above to buy from me locally (Derbyshire) and can't find any stockists. Is the only way to buy the Forte stuff online? Looks like even a few of the Halfords around me don't stock it.

I think so - it's a "trade" product I think (only normally available to motor dealers, garages etc), seems to be much better regarded than the one's that are available in halfords etc (e.g. redex)

EssexBoy · 18 May 2018 at 14:04

Yeah i had something similar and would hesitate at a certain rev range and start pulling again.I put some redex fuel treatment in to clear injectors/fuel system and it helped a little.

acemastr · 18 May 2018 at 14:04

Turbo would have an issue in all gears at high RPM.

I agree with fuel filter

Armageus · 18 May 2018 at 14:14

acemastr said:
Turbo would have an issue in all gears at high RPM.

Not necessarily with variable vane turbos, although probably more likely to be the EGR sticking I would think. Either way some "proper" diesel cleaner should sort it (even if only a temporary solution).

acemastr · 18 May 2018 at 14:20

Armageus said:
Not necessarily with variable vane turbos, although probably more likely to be the EGR sticking I would think. Either way some "proper" diesel cleaner should sort it (even if only a temporary solution).

True, I was thinking more slap it in 3rd gear and wind it all the way out and see if it either a) clears it, b) power loss, or c) blows up

MrMarvelous · 18 May 2018 at 14:33

I've ordered the Forte cleaner, can anyone point me in the right direction for a fuel filter? Ideally one that I could go and pick up today?

MagicBoy · 18 May 2018 at 14:39

GinG said:
It could well be your fuel filter.

Had the same thing happen in my A4 2.0TDI...changed the fuel filter and worked fine.

The fuel filter hadn't been changed in ages and when it came out it was black...I was told at the higher revs it would be starving the engine and sapping power.

Same happened to a colleagues Golf MkIV 1.9 TDI a couple months ago. Kept cutting out on the motorway and it as a duff fuel filter. Been fine since he swapped it.

Jumping to conclusions that it the Turbo, and shoving Mr Muscle in there is a really bad idea!

GinG · 18 May 2018 at 15:14

MrMarvelous said:
I've ordered the Forte cleaner, can anyone point me in the right direction for a fuel filter? Ideally one that I could go and pick up today?

Have you any Motor Factors near you?

Check out Euro Car Parts and see if there is a depot nearby to collect?

Semple · 18 May 2018 at 15:30

I get the fuel filters for my A3 from ECP.

Think they're less than a tenner, so get changed every year anyway.

MrMarvelous · 18 May 2018 at 16:02

Semple said:
I get the fuel filters for my A3 from ECP.

Think they're less than a tenner, so get changed every year anyway.

I've just had a look and there's 3 different ones, any idea which one I need? They're also doing a 35% discount on their site at the moment so i'll order online.

Semple · 18 May 2018 at 16:30

MrMarvelous said:
I've just had a look and there's 3 different ones, any idea which one I need? They're also doing a 35% discount on their site at the moment so i'll order online.

As long as you've popped your reg in, then any should be fine. I think they just have a few different brands.

I always double check the size with the currently fitted one anyway.

MrMarvelous · 18 May 2018 at 16:31

Yeah that's what i've done. Will pop into my local one tomorrow just to double-check and then i'll order it online. Hopefully it is just the fuel filter as looking around for replacement turbo's seems pricey.