VR6 running issue with video - fixed :shock:

[zak 0]

A few weeks ago i was driving my car and it started misfiring, I was a little worried as it didnt seem like the misfiring i used to get when my coilpack was going, this time the car was struggling to idle and also rev up. It was also putting out a lot of smoke from the exhaust. But as i was using poor quality leads on it and they were prone to arching i put it down to that. When i pulled up at the side of the road i could clearly see atleast two of the ignition leads arching on to the head so i thought i had confirmed my suspicions. I stopped at a petrol station and wrapped the two leads that were arching in insulation tape and took it for a drive, it was still misfiring but a few minutes in to the drive it stopped and drove normally so i drove the car back home. The next day i had a similar issue that the car started misfiring and then it stopped. When i got home it started misfiring again and hasnt stopped since then.

 

As it stands the engine starts and runs, the idle is lumpy and it struggles to rev up. It is also puting out loads of smoke that smells heavily of fuel.

 

I have done the following so far:

 

1. I changed my ignition leads and the problem still remains.

 

2. pulled the ignition leads one at a time from the coilpack whilst the car is running and the engine note changed on each one so all cyclinders do seem to be sparking,

 

3. I could hear a hissing noise from the idle control pot near the throttlebody so i bypassed it and the problem was still there.

 

4. Ive pulled out the spark plugs on each of the cylinders, they all looked okay albiet a little black on numbers 2, 4 and 6, also no oil on number 6 to be seen

 

5. Last night i scanned the car for error codes and it advised the following,

01242 - Output Stages in Control Module

34-00 - No Malfunction Detected

01253 - Fuel Injector for Cylinder 5 (N83)

31-10 - Open or Short to Ground - Intermittent

 

Tonight i will check the wiring for the injector but what is the other error code al about?

 

Heres a video of the car smoking on idle and also when giving it some throttle.

 

Anybody have any idea what is up with the engine?

[mic_VR 3]

Only time I've ever had white smoke like that it's been a head gasket starting to go. Have you checked for mayo in the oil filler cap, oil in the water and vice versa?

[zak 0]

theres no mayo under the cap, didnt see any obvious signs of oil and water mixing. The car does use a bit of water though.

 

If the head gasket was gone would it be possible for the car to run rough then run normally for a while before running rough again? As thats whats happened.

[Jim Bowen 1]

from my little experience, but i have had two cars with the headgasket go, that looks very much like a head gasket problem to me.

[zak 0]

when the head gasket goes does the smoke coming from the exhaust smell of fuel? Is there anyway i can check its the head gasket without taking the head off?

[CorradoVR6-Turbo 0]

That looks like the head gasket to me,and yes it will smell of fuel as it wont mix or burn correctly. Take out the plugs and have a look at how they are burning,that will tell which cylinder is to blame.

 

Also remove the expansion tank cap,top it up to the level,while letting it idle look out for air bubbles rising up and the coolant lever rising and falling as the bubbles come to the top,if it does its defo the head gasket bud. :(

[pete_griff 0]

maybe an injector?..... :?

[CorradoVR6-Turbo 0]

unburnt fuel = black smoke.

[zak 0]

I did take out the plugs, 1,3 and 5 looked normal, 2,4 and 6 were black. But Number 6 was excessively black with alot of build up on it. If it is the head gasket i will be somewhat relieved as i can get the car fixed next weekend. Its just random problems that i cant trace that i hate. If it is the head gasket looks i will be doing the chains aswell and might as well source another gearbox as mines crunching quite alot now.

 

I can't start the car at the moment as im having an issue with the starter engaging, see my other thread. I should have that fixed in the morning so i can investigate further.

[pete_griff 0]

unburnt fuel = black smoke.

 

ok, ignore my last! - sorry :ignore:

[KADVR6 0]

i have a gearbox for sale mate.

[antonio_b12 0]

i have a couple of injectors should you wish to try them.

[zak 0]

I fixed my starter issue today so was able to progress with working on the car.

 

I think i will try to resolve the fault codes before i look in to the head gasket. To resolve the fault code with injector 5 I just removed my inlet and swapped no. 5 and no. 6 injectors around as i couldnt see any issue with the wiring to injector 5. Im just going to go back to my car and re scan for fault codes and see if it logs a fault with injector 6 as this will confirm the injector is faulty. If the fault remains logged for injector 5 then will have to re inspect the wiring.

 

Pete i was just reading this thread of yours, my problem sounds remarkably similar, did you resolve the prob in the end?

http://the-corrado.net/.archive/forum/viewtopic.php?f=1&t=65640&p=762438&hilit=vr6+head+gasket#p762438

 

Karl thanks for the offer but if i need one i will source one locally

 

Antonio i might just take you up on the offer, just going to rescn for fault codes so i can eliminate the injector as being faulty

[pete_griff 0]

Pete i was just reading this thread of yours, my problem sounds remarkably similar, did you resolve the prob in the end?

http://the-corrado.net/.archive/forum/viewtopic.php?f=1&t=65640&p=762438&hilit=vr6+head+gasket#p762438

 

hey there buddy. well after i changed my head gasket it ran really really well for a couple of weeks - the best it ever has actually.

 

then it started to missfire again slightly - still haven't traced the fault.

 

i don't have vag-com and it's a pain in the arse to find somewhere that could scan it for me - would be nice to know before i take the engine out though.

 

it's bloody frustrating - the head gasket was just starting to go - confirmed by the bloke who skimmed the head for me, but it looks like that may not have been the cause of the problem after all! - and yes it's bloody frustrating if i didn't say that already! even more so as i'm stuck out here and can't do anything about it!

 

very interested to see what becomes of yours buddy - good luck with it all

 

Pete

 

edit: - another thing, my friend who is looking after it for me took the car up the road the other day and said that it was perfect - plenty of power and didn't missifre once!...

the saga continues!

[antonio_b12 0]

Antonio i might just take you up on the offer, just going to rescn for fault codes so i can eliminate the injector as being faulty

 

Yeah sure just let me know, think i have four or five working condition injectors about somewhere.

[Kevin Bacon 5]

You can run output tests with VAG-COM which will determine if you do actually have an injector or coil fault.

 

I would pull relay 167 (fuel pump) first though :wink:

 

Run the tests and you should hear the injectors clicking. Pull the plugs in turn and listen for any lazy injectors.

 

It's not unheard of for Motronic to develop an internal injector driver fault, but let's not go there just yet.

 

The main concern is why 2, 4 and 6 are all black....all the front bank. I doubt you have a split gasket across all 3 cylinders.

 

I'm thinking of reasons why that could be....

[zak 0]

I swapped injectors 5 and 6 yesterday and rescanned for errors, number 5 still came up showing an error so not sure if the injector is faulty. Upon the rescan injector 3 was also came up showin the same error which could mean a wiring problem but there was nothing obvious i could see. The connections to the injectors were all good, no green corrosion so a little confused where to trace this

 

Kev Thats a good tip i'll try that today

 

Regarding the plugs, i'll take pics of each one today so you can see what i mean but it is confusing why the front bank are black

 

anyone know what this error is about as its still coming up

 

01242 - Output Stages in Control Module

34-00 - No Malfunction Detected

[Kevin Bacon 5]

Output stages would refer to injector and coil drivers. But it's unusual for it to come up in the fault codes and say "No fault found", very odd. VAG-COM doesn't always translate every single error code correctly though.

 

Anyone near you with the same ECU you could try?

 

All 6 injectors share the same live feed, so check that wiring and also the coilpack wiring....

[zak 0]

The problem with injector 3 was my fault the connector was not plugged in properly from yesterday when i had the fuel rail off to swap the injectors around.

 

I checked the wiring for injector 5 and i could not find any issues with it, i checked the supply wire for continuity from the engine harness plug on the right hand side of the cylinder head to the connector that connects to the injector and it showed continuity. I also checked the common earth for the injector wiring and that was fine too.

 

I removed the engine ecu to check if there were any corroded terminals and all looked okay so i refitted it. Before refitting i rubbed the terinals down with emery paper and sprayed switch cleaner in to the ecu wiring loom plug.

 

Not sure where to go now, i would like to reseolve the error codes before tackling the head gasket if i even need to. I think it might be worth trying a another ecu, my ecu is part number 021 906 258AG if anyone has one?

 

heres the pics of my plugs

Cylinder 1

 

Cylinder 2

 

Cylinder 3

 

Cylinder 4

 

Cylinder 5

 

Cylinder 6

[fla 9]

Zak, I've got a spare ecu if you want to try it.

[zak 0]

That would be great, is it and ag part number?

[fla 9]

yep. Give me a bell some time.

[coullstar 0]

Plugs seem a bit "wet" to me or a tad oily. Should be a grey/brown finish.

[CorradoVR6-Turbo 0]

No 5 is well steamed clean....

[zak 0]

James i think you are right, as its the only plug which is white under the electrode. It's hard to see but plug 5 was wet with petrol too.