Possible solution for misfire and surging common to the a3

[mstirlz05]

I had the lumpy idle, restricted power, and misfires all happen the other day.
Didnt think it was the coilpack as audi fitted the revised ones not long ago, so avoiding the steep diagnosis that audi charge I booked it in at a local independant garage, and the problem was one Iv never heard mentioned on posts before.
Apparently it was a rear depth throttle body that needed tweaking, which to my surprise only cost me £40.
The worry is that the guy told me that if it re occurs then he was pretty sure it would be the throttle bodies themselves, and as you cant fit second hand ones, it would cost over £500.
Up to now it is running fine again, but this is a concern for me if it does happen again.

Does anyone know if this will be a permanent fix, or is it likely I will need new throttle bodies?

He also mentioned a turbo sensor, which causes it to hold back at times, though I dont think this is the cause for the misfires.

Thought Id mention this to anyone who is having the same trouble and hasnt had the revised coilpacks fitted, though Im no expert, it is just a possibility.

 

[beachbuggy]

Rear depth throttle body?.... Really...

£500 for throttle bodies?

Never heard of that!

What car you got and what engine...

Are you sure he just didn't put a pipe back, feed you a load of drivel and charge you £40 for it?

Sorry but it sounds a bit iffy to me

 

[<tuffty/>]

humm... ok... not sure what a 'rear depth throttle body' is... there is only one throttle body and depending on year/engine code will be drive by wire or cable... other than replacing the only real fix on a DBW (AUM engine code on the A3) is a throttle body reset... I assume yours is an AUM if you have had the coil packs done under the recent recall as AGU's are bolt down...

A 'turbo sensor' is a little ambiguous too... the ECU uses several sensors... MAF, MAP, air temp, Lambda, knock, cam position, crank position... there is no 'turbo' sensor as such...

<tuffty/>

 

[16Klappe]

What a load of b*llocks!

 

[s3gazz]

Sorry for the hijack would it be a good idear to change my Map sensor no reason why just want sensors to be new or is there a way of testing to see if it's ok tar

 

[mattyboy199]

once had a boost sensor fail which caused similar symptoms. I had to drive it pretty much off boost or it otherwised was jerky & misfired, the exhaust was popping which was nice.

 

[hades-]

dont you just love garages
prob reset the TB
and you can fit second hand i did

 

[sportstractor]

So basically you were charged £40 to do a throttle body reset... Which you could have done by removing and reinstalling the ecu fuse? Obviously if they also did a fault scan, £40 isn't the end of the world...

You can test the map by logging boost (channel 115 I think) vs requested and, if there's any strange results it's duff... If not its fine

 

[<tuffty/>]

Sorry for the hijack would it be a good idear to change my Map sensor no reason why just want sensors to be new or is there a way of testing to see if it's ok tar

Never known one go before... stop wasting money on sensors and get your engine running properly first... can't diagnose a problem that doesn't actually exist

To test you would need to log in VCDS block 115... and verify this with a boost gauge...

<tuffty/>

 

[s3gazz]

Cheers lads I'll just log it and see what happens then

And tuffty ya ryt again lol I'm on my way now just need xs manifold , agu head refurbed, rods and new uprated actuater fitting to turbo 10 psi in bar don't no or and mapping

 

[mstirlz05]

Well this is just what I was told. Its clear you all know more than me, but I have to rely on garages as after trouble with a thermostat, I found out that they arent the easiest cars to work on.

Whatever they did, it has cured the misfiring & surging so Im pleased for now. And it saved me money as I had numerous people telling me to change the ignition leads, fuel filter, coilpacks, dist caps etc etc.

So anyone who thinks it may be any of the above on their car, it could actually be a much cheaper answer.

Thanks for the input people, Im a bit more at ease, just hope he was blabbin about the TBs.