S4 misfire when starting from cold

Diagnostic Trouble Codes (DTC) / VCDS (VAG-COM) forum
Post Reply
yorkie
4th Gear
Posts: 699
Joined: Sat Oct 14, 2006 6:33 pm
Location: Cambridge UK

S4 misfire when starting from cold

Post by yorkie » Tue Sep 08, 2009 7:04 pm

Got this today on a mate's B6 platform S4 Cabriolet.

16684 - Random/Multiple Cylinder Misfire Detected
p0300 - 008 - Implausibe Signal - Intermittent

16685 - Cylinder 1: Misfire Detected
p0301 - 008 - Implausible Signal - Intermittent

16689 - Cylinder 5: Misfire Detected
p0305 - 008 - Implausible Signal - Intermittent

16687 - Cylinder 3: Misfire Detected
p0303 - 008 - Implausible Signal - Intermittent

16691 - Cylinder 7: Misfire Detected
p0307 - 008 - Implausible Signal - Intermittent

16686 - Cylinder 2: Misfire Detected
p0302 - 008 - Implausible Signal - Intermittent

Only happens when starting from cold.

Have looked at Ross Tech Wicki and there are too many possibilities.

Hoping someone has experienced the same.

Any help appreciated.

Cheers

User avatar
grizz
Cruising
Posts: 4074
Joined: Sun May 30, 2004 9:40 pm
Location: Unit 20 0151 33 66 888

RE: S4 misfire when starting from cold

Post by grizz » Tue Sep 08, 2009 7:08 pm

Try running with the maff disconnected ..
Unit 20
0151 3366888
The northwest's only dedicated 'RS' repair centre.
Image
http://www.facebook.com/pages/unit-20/104343529619713

yorkie
4th Gear
Posts: 699
Joined: Sat Oct 14, 2006 6:33 pm
Location: Cambridge UK

RE: S4 misfire when starting from cold

Post by yorkie » Tue Sep 08, 2009 8:31 pm

Thanks for the tip mate but I logged the MAF and it was flowing peak of 268 which by using the .8 calculation equates to 335 bhp which considering the temperature I thought looked ok. I am more suspicious of a temp sensor as this only happens around 10 seconds after starting from cold. Have done readiness tests and output tests without finding any problems. I must admit if a sensor was faulty I would have expected a "implausible signal" or "short to ground message" which I haven't got. That then leads me to suspect a mechanical problem such as spark plugs or injectors. Any more suggestions appreciated. Cheers.

baylissboy
Neutral
Posts: 32
Joined: Thu Jun 18, 2009 10:55 pm

RE: S4 misfire when starting from cold

Post by baylissboy » Sat Oct 03, 2009 9:35 pm

Does it make any odd rattling noises from cold, i had an similar issue, turned out to be the chain tensioners.

yorkie
4th Gear
Posts: 699
Joined: Sat Oct 14, 2006 6:33 pm
Location: Cambridge UK

RE: S4 misfire when starting from cold

Post by yorkie » Sun Oct 04, 2009 8:03 am

Cheers for the reply, I'll have another listen as I don't think he has had it sorted yet.

Post Reply

Return to “DTC / VCDS”

Who is online

Users browsing this forum: No registered users and 47 guests