A3 170 tdi down on power

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the obese penguin

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Had my car on the RR today purely a power run to get some bench figures so I know where I'm starting at and also to see if there is any underlying issues.

Turns out the car is making 161bhp and 226ft/lb

I would expect to see at least 190

Car has got egr delete/ dpf removed and remap from prior owner, but I haven't got any paperwork on this work other than the bill.

Graph below shows the curves.

Any gurus on here shed any insight as to where to start looking to try and iron the problems out.

Cheers

 
DPF-delete 170 can feel really quick for a 2.0TDI, I was very impressed with mine and felt that the clutch was on the edge all the time, if you breathed on the throttle at 35 in 4th it would take off.

My currently 170 (standard) is much slower, but still reasonably quick.
 
What about things like poor idle, poor mpg etc that I keep reading about.

The car pulls well and doesn't feel like theres anything wrong but clearly there is.
 
It depends on what is actually happening to the MAF reading. Mog and idle won't be effected by a MAF that reads low across the board. You need someone with a scanner or VCDS to check what the MAF value is on full throttle. I can tell you then if that's your problem.

Rick
 
Its going to my friendly VAG mechanic on monday and will be doing some investigative work.. Will update when know any more
 
The other thing to bear in mind is that part of the EGR valve flow measurement is based upon the incoming air flow readings from the MAF. If the MAF doesn't read correctly the EGR can be flowing more hot gases back into the engine than it should under acceleration (the valve should close under hard throttle), thus losing boost & power.
 
c_w said:
DPF-delete 170 can feel really quick for a 2.0TDI, I was very impressed with mine and felt that the clutch was on the edge all the time, if you breathed on the throttle at 35 in 4th it would take off.

My currently 170 (standard) is much slower, but still reasonably quick.
Click to expand...

Is DPF removal now an MOT failure? I know many garages wouldn't mind ignoring that but does it now technically make the car illegal?
 
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The standard output is 167bhp AT THE FLYWHEEL.... you've got 161 AT THE WHEELS when it's gone through the gearbox / drive shafts / cv joints & rolling resistance of the tyres. Personally I wouldn't be overly disappointed tbh!
 
Bedders said:
The standard output is 167bhp AT THE FLYWHEEL.... you've got 161 AT THE WHEELS when it's gone through the gearbox / drive shafts / cv joints & rolling resistance of the tyres. Personally I wouldn't be overly disappointed tbh!
Click to expand...

Nope.. 161 @ fly 134 @wheels. Its says that clearly on the printout
 
Oops sorry couldn't see that as reading on my phone not pc monitor. Yep you've got a problem! Can you hear any top end high rev turbo whistles? Poss boost leak?

What version of 170bhp motor have you got? Bmn by any chance? Plastic inlet manifold are known to crack / leak near the swirler valve motor! I'd get it boost leak checked before anything else.....if the full amount of boost isn't getting to the engine then you won't have the power. Another thing to consider is the age / mileage of the turbo. When they wear they have a habit of leaking oil from the bearing which them settles in the inter cooler pipe work. All buggers up the oomph getting to the motor. Good luck with sorting & let us know what you find out.
 
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Bedders said:
Oops sorry couldn't see that as reading on my phone not pc monitor. Yep you've got a problem! Can you hear any top end high rev turbo whistles? Poss boost leak?

What version of 170bhp motor have you got? Bmn by any chance? Plastic inlet manifold are known to crack / leak near the swirler valve motor! I'd get it boost leak checked before anything else.....if the full amount of boost isn't getting to the engine then you won't have the power. Another thing to consider is the age / mileage of the turbo. When they wear they have a habit of leaking oil from the bearing which them settles in the inter cooler pipe work. All buggers up the oomph getting to the motor. Good luck with sorting & let us know what you find out.
Click to expand...

Yes its a BMN... Getting a smoke test done on monday and erg and inlet manifold coming off to see if they are gunked up.. Egr is blanked off and mapped out but since it was done before I owned it, I don't really know whats what, so as said above, things are coming to take a good look around..
 
Does engine look particularly smokey when under full throttle? If you've got a boost leak, sometimes not always, it may look more smokey than normal. Think it maybe down to over fueling as boosted air is escaping before it's thrust into the engine but it's still throwing in the juice so leads to more smoke than normal.
 
Bedders said:
Does engine look particularly smokey when under full throttle? If you've got a boost leak, sometimes not always, it may look more smokey than normal. Think it maybe down to over fueling as boosted air is escaping before it's thrust into the engine but it's still throwing in the juice so leads to more smoke than normal.
Click to expand...

Not that Ive ever noticed..

I'll update in monday if we gain any insight to the issues
 
Today the car had a smoke test, no boost leaks found.

Scanned on vcds and no fault codes..
Turbo has minimal play
MAF Sensor was checked and the (actual) reading via vcds was 450-700 varying between idle and revved.

Egr was taken off and cleaned, it had small amount of gunk but hardly anything and we discovered the erg has been blanked off as it should be. So at the moment no clearer picture what may be causing it.
 
With the maf you do a 4th gear run and see what g/s don't you?

Can't be massively different to a petrol :/
 
What mileage has it got on the car? Do you think the turbocharger might have been changed? Not sure how backwards compatible they are but think the 140bhp turbo looks similar on the manifold type. Think I'd be checking that first off....140bhp turbos are ten a penny & much cheaper whereas the 170bhp turbos are bigger compressor wheels & more boost. Worth checking the plate on the outer casing to make sure it's the right model charger! (Reason i say check is that is I've seen people changing the 170bhp plastic inlet manifold for the 140bhp as a replacement plastic one is £500 new when it breaks & they do, for an alloy one off a 140bhp £60 off eBay. Suppose someone could do same with a turbo charger) Just clutching at straws but watching this post with interest.
 
max69vk said:
140 turbo won't work on a 170 as the VNT is controlled differently between the 2.
Click to expand...

Ah forgot about that yep isn't one vacuum n one electronic! My bad. Must be a reason for this motor being down on power.
 
When was the fuel filter last changed? They're meant to be good for 50,000 miles according to Audi... I change mine yearly with the annual service as it's always full of crud.
 
max69vk said:
When was the fuel filter last changed? They're meant to be good for 50,000 miles according to Audi... I change mine yearly with the annual service as it's always full of crud.
Click to expand...

Fuel filter was done with last service, less than 5000 miles ago.. Today replaced the Egr valve with a dark side Egr delete pipe and now it has a intermittent hesitation under boost.. So now its probably got a leak or boost hose is collapsing perhaps thats what it feels like. Not related to the problems above though
 
So on further inspection today, Im almost certain the issue in the original post was EGR related, even though it was blanked and mapped out, perhaps it had an air leak (even though we checked) or maybe it was just being restrictive who knows...

It now been replaced with a delete pipe... Big difference.. Pulls like a monster, however it now has a leak..

Now Im almost certain it has a boost leak from the boost pipe that leads away from the anti shudder valve.. It must be twisting or moving slightly as when it holds full boost the car pulls like a monster and shows no issue from the original problem in original post.. Looking at the pipe the lugs look worn and seal had seen better days, so replaced the seal and has made a shade of difference but it still shudders and hesitates, so ordered a new pipe and will go from there..
Would love to get the hard pipe kit from dark side but can't afford it at the moment :(

Will fit over the easter weekend and will update then
 
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