S3 sometimes under performing in colder weather

Damo S

Registered User
Anyone else have this?

When its hot outside the car is fine and consistent, but now its got colder it feels a little flat to start with (once oil is up to temp) but after Ive ragged it a few times or its been running for a good 20 mins or so then it seems to sort itself out.
Boost pressure is stable it just feels to me like its pulling the timing. This is very noticable by the lack of off boost oomph. Once it has sorted itself out it seems way more responsive off boost, comes on boost quicker, and the midrange torque is stronger.

I did have an issue last year after the garage serviced my brakes, the pads were rattling about in the callipers and this seemed to have a similar effect on the car. I'm also starting to think the same is true after I've been driving along some very bad, bumpy roads. So I'm wondering if perhaps the knock sensor is failing (sensitive to heat / external vibration / noise) and is giving the ecu some dodgy readings so its pulling the timing. It's the only thing I can think of. Like I said once it decides to sort itself out the car runs absolutely fine.

anyone else had anything similar?
 

AlS3BE

Registered User
Sounds like it could be bad fuel.
Get something similar when I fill with normal 95 Ron when super isn’t available.
 

CanadaA3wales

Canadian living in South Wales - Audi A3 8V 150BHP
I know I only have a 2.0TDI but I have tried BP ultimate in my old golf and did not notice a difference, but when I put it in this Audi I am telling you there is a 100% difference between tesco and BP ultimate Diesel.
But I dont push my car until its warmed up anyway so not sure if there is a difference between cold and hot.
 

Damo S

Registered User
I run mine on 99. It's not the fuel its consistent across tanks and once its sorted itself out its fine.

I dont boot my car until the oil temp is up to at least 80C. That takes close to 10 mins in this weather, but its still a good 10 mins after that or some spirited driving before it sorts itself out.

and like I said there are other factors which seem to have an impact: heat and impact noise / metallic vibration.
 

AlS3BE

Registered User
Check coolant temp sensor and map/ maf( not sure what the s3 has) and see what they are reading when cold to warm.
 

Damo S

Registered User
S3 has a map sensor I believe. Coolant temp sensor might not be a bad shout actually. I think that's available on torque pro. still reckon the knock is playing up though.
 

AlS3BE

Registered User
S3 has a map sensor I believe. Coolant temp sensor might not be a bad shout actually. I think that's available on torque pro. still reckon the knock is playing up though.
Think you can monitor the knock sensor on live data in vcds somewhere too. If it was kicking in enough it should throw the eml.
Another thing it might be is the spark plugs are too cold a rating for your car and because of the weather it’s more apparent till it all warms up. I’m Just guessing though.
 

Damo S

Registered User
Think you can monitor the knock sensor on live data in vcds somewhere too. If it was kicking in enough it should throw the eml.
Another thing it might be is the spark plugs are too cold a rating for your car and because of the weather it’s more apparent till it all warms up. I’m Just guessing though.

Plugs. possible might ask the tuner about it to see what they think.
 
Top