A Query for those technical out there

[P_G]

Unfortunately I have experienced my first major problem with the RS today in 4 years on ownership. Took it out today for a run at lunchtime as it hadn't been used since Monday and when warming up felt a slight misfire but went as the revs invcreased. Drove for another 20 or so miles with no issues through the entire rev range but then had to stop for petrol.

After starting up again I drove down to the first roundabout and the engine cut out. Odd. So started up again and coasting at low revs the engine cuts again. Then starting it the third time and there is a distinct misfire and it progressively gets worse. Pull over to do a VCDS scan on the car and sure enough multiple misfires detected code and then lists cylinder 1 and 5. Decide that since I'm only a mile or so away from Tyneside Audi I'll take it there misfiring away and cutting out every time under 1500rpm i.e coming to a junction. When I get there it cuts out again and another scan shows misfires on cylinders 5,1 3 and 2 and the IM runner flaps are both implausible signals. Start it up again and it is misfiring horribly and hunting for 10-15 seconds or so at idle and then cuts out. Of course EML flashing and EPC on

So it is now sitting at Tyneside awaiting inspection.

Any ideas? Could damaged lambda sensors cause such misfiring. I only ask as I cleaned the full underside of the car at the weekend with a pressure washer except of course the engine bay.

[Doug_S2]

Sounds like a vacuum leak off the inlet manifold so it sucks in too much air and cannot make it idle.

[sonny]

Hope its a easy and simple fix.

[P_G]

Would that cause misfiring as well Doug?

The codes were;

Right Engine Solenoid Valve (N145): Open Circuit
P1577 - 004 - No signal / communication - Intermittent

000768 - Random / Multiple Cylinder Misfire Detected
P0300 - 001 - Upper Limit Exceeded

000769 - Cylinder 1: Misfire detected
P0301 - 001 - Upper Limit Exceeded

That was the first scan, I didn't get a chance to log the second scan.

[Doug_S2]

it would cause misfires as well

[P_G]

Thanks, let's see what the masterminds at Audi come up with.....

[RSKiwi]

Thanks, let's see what the masterminds at Audi come up with.....

My money is on

'No problem sir we have changed your washer fluid and rear wheel TPMS sensor its all fixed' ....followed by cheesy grin and their hand out for £923.36


Youd drive out the gate with the car in exactly the same shape as when it went in.....

Spot the person who has been burnt by Audi before?!!

[P_G]

They know me better than to do that, I must be one of their 'loyal but pain in the ass' customers.

[Timster]

Thanks, let's see what the masterminds at Audi come up with.....

My money is on

'No problem sir we have changed your washer fluid and rear wheel TPMS sensor its all fixed' ....followed by cheesy grin and their hand out for £923.36


Youd drive out the gate with the car in exactly the same shape as when it went in.....

Spot the person who has been burnt by Audi before?!!

lol... yeah. I bet the first time you come to use the washers... they're empty !

[Revolution]

any news on what it is......?

[P_G]

My source on the inside says the master techs are looking at it now.

[Revolution]

fingers crossed for you...

[Revolution]

Have you heard anything yet?

[adsgreen]

Agree with doug on this.
I did some vacuum system testing as per the tech bulletin. Once finished I just started the car (as opposed to ignition key out) so for a split second there was no vacuum.
By god did the car complain - multiple misfires, manifold flap codes, flashing MIL and EPC lights on.
I shut off the car (after a big "oh feck I've broken it" moment) double checked the connections I'd used to manually test, and then restarted from cold after clearing all the fault codes. Everything back to normal and never troubled me again.

So yes, does sound like the connection/valve under the inlet manifold has gone or there is some other big vac loss somewhere . However as per the TSB you can test this without taking the manifold off - just disconnect or T the various vac lines and see what pressure it attains and what it's holding. Even easier if you use a hand vacuum pump to test. Shouldn't be no more than an hour (probably less) to diagnose if the IM has to come off.

[P_G]

Hopefully Audi's mastertechs are as insightful. Just seems odd that after a good few weeks it catastrophically lets go like that?