Cold morning start problems.

[Audiman99]

Hi, recently the car has been acting very strange in the mornings, starting wise its fine it will start as soon as I turn the key and stay running, but every now and then I will start the car and it will sound like the engine is trying to jump out of the engine bay there’s a weird pumping noise that sounds like its struggling to do its job. Plus it idles really bad dipping really low like its about to stall, and I cant drive it either as the gas pedal doesn’t respond properly.

Thing is I turn it off and back on again and it seems fine. Apart from it seems to be in safety mode not allowing me to rev it high and limiting it to what feels like 100bhp.

Do you think this is a major problem or just the cold weather not getting on with the car, oh and every now and then the coolant warning pops up, I did top it with water and it came back the other day!!! Maybe I need a new sensor?

Any advice would be appreciated guys,

Thanks

Allan

 

[LaSarthe&Back]

Oh dear, sounds like a few problems you got.

First, have you checked the coolant level? If not, top it up and see if it does it again. The coolant temp sensor can cause a few problems for cold starts. Jerky acceleration, taking about 10 secs to start engine... I would change it anyway.

How many miles has your car done? Is it chipped? Regular oil changes? Have you had the oil pump changed? Heard a few stories on pumps failing.

Your poor idling is probably caused buy the good ol trusty MAF!!

Andy

 

[TheSpaceCowboy]

Also with regards to the idling, check the air filter, I changed out my filter and the car idles a lot less erratic. It was nearly black.

 

[eddyg]

All of last winter I had a similar issue on my 2002 S3. From cold it would
initially start OK, and then the revs would drop, almost stall, and then run rough for ~5secs. Then it would run fine all day.

Had mechanics try to analyse what it was, couldn't figure it out. Sensors all appeared to be OK. Cost too much to start swapping them all out.

I worked around the issue by giving it a few revs (~2000rpm) just as I started the car.

Anyway - my battery died two weeks ago, and so I replaced it. Since
then it has started perfectly.

So - either it was because my battery was naf (I noticed that the alarm beep is a lot churpier with the new battery. So maybe the battery has been on the way out for ages). Or possibly more likely the extended period (15mins) with the battery disconnected caused the car to do a full ECU reset which fixed the issue.

So it's worth disconnecting your battery to see if that helps, and if not
consider a new battery if it's old anyway.

Cheers, Ed.

 

[simch]

coilpacks and plugs seem likely candidates here, according to our french friends over on S3 Passion!! Symptoms like you describe and apparenly there are updated coilpacks that dealers may fit even outside warranty......??

When the maf played up on my golf, it just lost some revs and top end, as boost was pulled back after about 4k revs. Sound slike your engine jumpin about could be misfiring....??

 

[Audiman99]

thx for the help guys, ive booked it in for wednesdsay to have a full service, its on 84k at the mo, and is over due a service so gonna get a proper one done.

bout to go scan car as well, ill post back results in a bit.

Thanks

 

[Audiman99]

Just scanned and got this

VAG-COM Version: Release 409.1-S


Chassis Type: 8P - Audi A3/S3
Scan: 01,02,03,08,09,15,16,17,19,25,37,42,44,46,47,52,55,56,57,69,75,76,77,7D

-------------------------------------------------------------------------------
Address 01: Engine
Controller: 8N0 906 018 
ö
Coding: 10710
Shop #: WSC 78385
Note: Excessive Comm Errors

-------------------------------------------------------------------------------
Address 03: ABS Brakes
Controller: 8N0 907 379 E
Component: ESP 20 CAN V005
Coding: 18448
Shop #: WSC 06435
2 Faults Found:
01423 - Lateral Acceleration Sensor (G200)
57-10 - Electric Circuit Failure - Intermittent
01423 - Shareware Version. To Decode all DTCs
27-10 - Please Register/Activate - Intermittent