Audi A4 2.4 V6 Quattro Possible Misfiring?

[UKSoldier71]

Good Morning Guys & Gals,
I am new to this forum so a big warm hello. I currently a serving British Army Staff Sergeant and have served over 20 yrs in the British Armed Forces for my sins lol. Also a northern lad from Rochdale. I am currently based in Germany. I however come home to blighty as often as i can get over.

I currently have a 2002 Audi A4 2.4 V6 (86K). Its been driving very well and i
have spend a lot recently on alloys, wishbones all round, 2x rear shocks. Oil change etc.

The engine management light came on, on a slow drive on the autobahn so i had it investigated. The machine plugged into the management came out with codes indicated it wasn't firing on 5&2 properly. It was running fine before i put this oil in. I believe the timing belt was changed at 69K. I have been told but not fully 100% because it was a duplicate service manual.

This means nothing to me apart from i am not getting out of my engine that i
expect. In your experience Is this pricey to fix? What could
cause this? Known faults? spark plugs? spark plugs distance? Ignition Coil Pack? Timing belt?

The funny thing is it only started once i put some good quality grade oil in. I have checked and i have not over filled it . I really would like your advice and expertise guys.

How much do these parts roughly cost? P&P? I have a general idea but thought people my have other links.

If this car engine is knackered who knows of a good re-conditioned engine company? I have available funds. Or maybe possible engine up grade for a little more power?

Helppppppppppppppp please, lol.................I will be putting my car in the
German garage tomorrow and will hopefully know more. I like to go in there with a little heads up. I hope i am worrying for nothing but garages have a great way of shaking or scratching their heads making the situation sound even worse than it really is. The German garage dealers like to rip us Brits off over here and parts can be really expensive. You have to love ebay ha-ha.

I really am a car biff when it comes to this. I look after my cars and give
regular inspections so know its not me. Well i hope not anyway. I seek your
advice and I welcome your precious time to reply. I have done some investigation in other car related forums and it suggests all the faults that could cause this problem i have listed above.

I was really hoping i could pick a few more larger car brains than my own, lol

Sorry for the long winded question but i like to give as much information as
possible.

I look forward to hearing from you very soon,

Regards

Jay Thomas

 

[Yugguy]

Howdo.

What happens if you clear the codes? Could just be a sensor. Daft question but when doing the oil change did you disconnect any sensors, with the ignition on? This might make the ecu think a sensor is faulty or missing.

 

[UKSoldier71]

Once it was re-set by the garage after a few seconds of driving it came back on again. At tick over there was a prominent small vibration. I don't want to drive it to much in case more damage is done.

No other connections were disconnected.

Thank you for your reply.

 

[T9 man]

Greetings and Welcome to TorqueCars!

 

[UKSoldier71]

Thank you.

 

[HDi fun]

If you can detect a vibration then the diagnostic report is probably correct.

5 and 2 will be the middle cylinders on each bank. Does your car have a coil per plug or does it work on the wasted spark principle (ie. one coil for every two plugs)?

The oil will not have caused this directly, however. Though, as said, you might have disturbed something during the oil change process. The belt won't cause this problem. New coil(s) and plugs would be a good idea.

VAG should be able to rectify this pretty cheaply in my opinion. If not, then take it to another dealer - many of the OBD2 diagnostic codes are not manufacturer specific, especially if the fault is emissions related so, for example, BMW or Saab would equally be able to repair it for you.

In any case, I don't think you're in for anything scary at all.

I think you're right to not drive it - you could poison the emission control systems and wind up with a huge bill.

 

[UKSoldier71]

@ HDi fun,
Thank you very much for your words of confidence. I always do my home work because garages have to make a living i am not anti garage but the German garages do tend to rob us HMF off lol.

I am unsure how many coils and what set up my car has but that will be my next investigation.

I have already priced most parts up in advance of the replies i received. So the ball is rolling. Labor prices are always interesting but this sounds promising. If its a quick job to rectify.

I have a general idea about cars and combustion etc etc blah blah but wanted clarification from a better car head(s) than my own ha-ha.

Stay safe and i will keep you up to speed and what the out come were.

On the back on end of that reply. What would remapping my V6 give me for a return on higher BHP? Currently its at aprrox 170. What is a realistic improvement from re-mapping? 25-30 BHP? also does it interfere with your MPG after its done. Currently on a 65 ltr per tank of fuel and averaging 85 MPH i get about 440 miles fuel light on. That's on a full tank and driving on the German Autobahns.

Thanks for the help guys.

 

[obi_waynne]

To diagnose a coil pack issue, swap the coil packs over and see if the fault code moves with them. Chances are it will and you have identified the fault. If the fault remains then it could be the leads so swap these around*.

*(A word of warning, don't change the firing order by mixing up the leads - it will kill the engine. Label where each lead plugs in very carefully and do 2 at a time rather than all of them.)

 

[pgarner]

if they scanned it properly then it would have shown which cylinder was missfiring.
you should have 1 coilpack for each cylinder and they are prone to failure. 2 min job to swap them out. and you shouldnt have any issues with the leads as they are tied down beside each cylinder

 

[UKSoldier71]

Thank You guys. It's very much appreciated you taking the time to replay. It suggested that it was misfiring on 5 & 2. So this will mean 2x ignition coils to be replaced? I will order set of new high quality spark plugs change these and have a few coils on stand-by.

Once again

A big thank you.

Regards

Jay

 

[jarrus]

Yeah I would have said it was a coil pack thing, just a coninsidence.

Do you not have a Mechanical shop at where you're based in germany? Maybe one of the guys could confirm it for you, we all think it's the coils have gone maybe you could ask someone over in your base?

Coil packs aren't hard to change so if you can buy them from somewhere then you'll be able to fit them easily enough...

 

[pgarner]

shouldnt really be suggested if they are reading it right mate it would actuatly show 3 error codes at a minimum

1 for multiple missfire
1 for cylinder 2
1 for cylinder 5

and you may have some other ones for fuel trims being out.

when you order the coil packs make sure you get a couple of spares as normally when they start to go the rest wont be far behind

 

[UKSoldier71]

I will now check then individually: I have replaced all new spark plugs, second hand but working coil ignition cables x6 and fuel management control. The symptoms are still there. I am thinking now fuel injectors? ideas guys. Looks like the rip off German garages might be seeing me sooner than i thought lol

 

[drew104]

you have a bad ignition power output stage chip that is bad there should be 2 chips mounted to the air cleaner box one chip is for cyl 1,2,3 and the other chip is for cyl 4,5,6