S3 8p loosing power

K

Kayu

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Help me diagnose a problem please... my car is 265bhp standard I got it dynod at 180bhp at the fly today! Yes 180! that's 85hp lost!

No codes are coming up what so ever. East coast said it was under boosting reading 0.8 bar and it should read 1 bar. They said it could be the actuator or the N75 valve but I don't want to be buying parts that are not needed.

Audi specialist I went to last week said it was over boosting but if that was the case should the car not go into limp mode to protect the engine? They also suggested to get a remap to support the mods I have and it should solve the problem but if the car is not at standard power then there's no point remapping it.

I've got a cat back miltek exhaust, a VWR Induction kit, a Forge Pcv delete heat shield and a gold heat wrap for the induction kit.
 
Have you checked your DV for any breaks? This will give you a big boost leak! But I'm sure they could have worked that out at the RR :/ and then change then change the n75 valve, process of elimination if there's no codes
 
Cambaines said:
Have you checked your DV for any breaks? This will give you a big boost leak! But I'm sure they could have worked that out at the RR :/ and then change then change the n75 valve, process of elimination if there's no codes
Click to expand...

Diverter valve you mean? I checked it and all the rings doesn't seem to be broken.. it's the old one so it's all plastics. I'll be looking into buying the metal one soon but it doesn't seem to be damage atm
 
180! Wow! Carbon build-up can also be a contributing factor too, so might be worth considering a carbon decoke using media blasting. My neighbor was down almost 100bhp in his RS4 before he had the intake cleaned out.
 
Had something similar surface when I put a Revo intake on (problem persisted after reverting back to standard intake so it just highlighted rather than caused). Car would go into limp mode sporadically.

What I ended up changing: PCV & Pipework, Plugs, Coil Packs, Check Exhaust for leaks, Check HP sensor and LP sensor on Fuel Pump, Check Battery, Replace Recirc Valve.

In the end I think we solved it, someone had been in about the loom and left 'Pudding' joints all over the place, cam sensor wire had an intermittent signal and another connection nearby was seated poorly. Any movement would almost kill the engine.

I was getting 0.9 Bar instead of 1.2 Bar of boost after some diagnostics, and it was starting to boost late at 4k instead of 3k whether it's still doing that or not I don't know.

Anyways, long ramble of a post, hopefully something there will help you get it sorted. A pressure test would be your best place to start.
 
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I found that one of the real problems with this engine is that it's monitoring systems are quite complex,and that it will keep running even with multiple problems.
Mine suddenly ran very rich a couple of yrs ago.....we found the following:

Thermostat stuck
MAF dirty
MAP sensor dirty
Lambda probe not accurate
Throttle body load correction factor completely wrong.

No error codes at all.

The coking thing is a well known issue,but shouldn't account for all the lost horses.
 
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Know anyone that can d
leshkin said:
180! Wow! Carbon build-up can also be a contributing factor too, so might be worth considering a carbon decoke using media blasting. My neighbor was down almost 100bhp in his RS4 before he had the intake cleaned out.
Click to expand...

Know anyone that can do it?
 
Kayu said:
Know anyone that can do it?
Click to expand...

Hands on methods such as Walnut/Media Blasting are the best of which AMD Tuning in Essex offer this service as well as AwesomeGTI in Manchester, other places also do it but are difficult to locate. If either are too far away from you and no-one else is near, then the next best thing you can do is an engine carbon clean which is done by the following company who offer a mobile service: http://www.enginecarbonclean.com/
 
HHS3 said:
Hands on methods such as Walnut/Media Blasting are the best of which AMD Tuning in Essex offer this service as well as AwesomeGTI in Manchester, other places also do it but are difficult to locate. If either are too far away from you and no-one else is near, then the next best thing you can do is an engine carbon clean which is done by the following company who offer a mobile service: http://www.enginecarbonclean.com/
Click to expand...

Thanks mate I'm booked in for tomorrow evening. Hope it helps a bit
 
Been down to a revo today and they said that my car is at the correct boost level (1 bar) they said my cars timing is wrong and could be a number or things but would not specify. I mentioned carbon build up and they said that could help. I'm based in Northern Ireland which is a pain in the **** to get anything. No one that I've found that can do media blasting so I'm going to the engine carbon cleaned as mentioned above and see if it'll make any difference. Thanks for all your input, I'll keep you updated
 
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Kayu said:
Thanks mate I'm booked in for tomorrow evening. Hope it helps a bit
Click to expand...

Kayu said:
Been down to a revo today and they said that my car is at the correct boost level (1 bar) they said my cars timing is wrong and could be a number or things but would not specify. I mentioned carbon build up and they said that could help. I'm based in Northern Ireland which is a pain in the **** to get anything. No one that I've found that can do media blasting so I'm going to the engine carbon cleaned as mentioned above and see if it'll make any difference. Thanks for all your input, I'll keep you updated
Click to expand...

You're welcome mate, I'm interested in getting this done myself so let us know how you get on.
 
The hydrogen carbon clean does not always help. It definitely loosens stuff and allows it to move through the system, but on a badly affected car it will likely cause issues as the intake gets clogged up with gunk from the ic, turbo, etc

After doing it, I feel like it's best done before a media blasting session as you get to clean out the crud that has accumulated there. My wife's mini is going in for media blasting after carbon clean did not completely fix irregular throttle response/acceleration. Car is 9 years old and only 30k on the clock and feels like its previous owner wasn't giving it the full welly often enough.

Sent from a mobile device, please forgive typos :)
 
I had my old van carbon cleaned via the hydrogen method , not convinced it made any difference at all tbh .
 
leshkin said:
My wife's mini is going in for media blasting after carbon clean did not completely fix irregular throttle response/acceleration. Car is 9 years old and only 30k on the clock and feels like its previous owner wasn't giving it the full welly often enough.

Sent from a mobile device, please forgive typos :)
Click to expand...

Slightly OT but our 07 MCS had the walnut blast done and ran a lot better, however it would still hang back at times especially on warm up.
After numerous dealer tinkering visits to no avail, I changed the fuel filter in the tank fuel pump. Bingo the car runs like a dream now the filter was black and surrounded by silt.
Worth considering if you still have issues:yes:
 
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-Ju- said:
Slightly OT but our 07 MCS had the walnut blast done and ran a lot better, however it would still hang back at times especially on warm up.
After numerous dealer tinkering visits to no avail, I changed the fuel filter in the tank fuel pump. Bingo the car runs like a dream now the filter was black and surrounded by silt.
Worth considering if you still have issues:yes:
Click to expand...


That's the next thing I'll be changing if the carbon cleaning doesn't help. Rather cheap fixes. Thanks
 
audi upgrades
The car may run a little better after the carbon clean but no way is it robbing that much bhp.
How does it feel to drive?
Is the dv the old diaphragm type? If so have you checked for splits.
Is the vwr the sealed intake and does it have the post warranty insert in?
Is the Maf good?....try unplugging it and running unplugged
Recheck all the hoses are tight and have no leaks especially the one underneath the car at the end of the metal turbo outlet pipe.
Get yourself vcds to make things easier!
 
My timing was out when Apr was trying upload a new map, I was told main possible cause is poor fuel, to change plugs for a cooler set and if it's still running out it could be and over sensitive knock sensor


Sent from my iPhone using Tapatalk
 
-Ju- said:
The car may run a little better after the carbon clean but no way is it robbing that much bhp.
How does it feel to drive?
Is the dv the old diaphragm type? If so have you checked for splits.
Is the vwr the sealed intake and does it have the post warranty insert in?
Is the Maf good?....try unplugging it and running unplugged
Recheck all the hoses are tight and have no leaks especially the one underneath the car at the end of the metal turbo outlet pipe.
Get yourself vcds to make things easier!
Click to expand...

Boost kick in more ferocious when cold and when the engine gets to temperature you can feel the boost disappearing. It only boost from 3k to 4500rpm then it tails off. It could be Maf as the car is now idle hunting but wasn't before.
 
Ben2487 said:
My timing was out when Apr was trying upload a new map, I was told main possible cause is poor fuel, to change plugs for a cooler set and if it's still running out it could be and over sensitive knock sensor


Sent from my iPhone using Tapatalk
Click to expand...

I only use BP ultimate in the car since I've owned it though will check the plugs as well mate
 
-Ju- said:
The car may run a little better after the carbon clean but no way is it robbing that much bhp.
How does it feel to drive?
Is the dv the old diaphragm type? If so have you checked for splits.
Is the vwr the sealed intake and does it have the post warranty insert in?
Is the Maf good?....try unplugging it and running unplugged
Recheck all the hoses are tight and have no leaks especially the one underneath the car at the end of the metal turbo outlet pipe.
Get yourself vcds to make things easier!
Click to expand...
Kayu said:
Boost kick in more ferocious when cold and when the engine gets to temperature you can feel the boost disappearing. It only boost from 3k to 4500rpm then it tails off. It could be Maf as the car is now idle hunting but wasn't before.
Click to expand...

Also the dv is the old plastic one. I took it out and checked it and have no split in it atm
 
Unplug the maf and try it, it'll run fine without

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audi upgrades
Also check the pcv delete is fine, does it make a difference when the oil filler cap is undone at idle?

Sent from my SM-N915FY using Tapatalk
 
-Ju- said:
Also check the pcv delete is fine, does it make a difference when the oil filler cap is undone at idle?

Sent from my SM-N915FY using Tapatalk
Click to expand...

The pcv delete is only brand new two weeks ago can't see being a problem tbh.

Tried taking the oil cap off while idling and no pressure but it had pressure last I checked
 
Yeah you'll get the engine light on but it will run fine and then go off when you plug it back in.


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Carbon clean guy came out plugged in the hydrogen for 30 mins and started revving the car to clear it it up. The car was at neutral and it just conked out. This happen several times. Took the Maf out while the car was idling and the car cut off as well. Any idea what could cause this? This is becoming quite a hazard as the car cuts out while in motion (mainly 10mph for now) the guy didn't charge me which was a plus as he didn't think the hydrogen made any improvements because of the oy
 
I think you're spending a lot of time trying various fixes without knowing what exactly is wrong with the car.

Take it to a good independent tuner,preferably someone well known from here,and let them get some time with it,to log it properly.
I do know that being in N.Ireland isn't helpful in that respect,but this way isn't getting you results,just more time and more questions.
 
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Kayu said:
The pcv delete is only brand new two weeks ago can't see being a problem tbh.

Tried taking the oil cap off while idling and no pressure but it had pressure last I checked
Click to expand...
Are you saying then that removing the oil cap while idling is easy and makes no difference?
 
S3Alex said:
I think you're spending a lot of time trying various fixes without knowing what exactly is wrong with the car.

Take it to a good independent tuner,preferably someone well known from here,and let them get some time with it,to log it properly.
I do know that being in N.Ireland isn't helpful in that respect,but this way isn't getting you results,just more time and more questions.
Click to expand...
OK thanks for your input
 
I would double check the pcv delete then by refitting the old one
These are all non cost things to do before you dig deeper
 
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