Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[jtypecav]

Still buzzing from my new acquisition. Still has new car smell, is just under 70k. But it has a crazy problem which is going to do ky head in until I can get it plugged into a scanner.

Car is great for about 15 mins or until hits 70mph+ or 3k+ rpm sustained. s smooth powerful, even throaty until this point.

Stage one. Eml flashes comes on, performance is still unaffected.

Stage two. About 5mins later car starts to feel like its missing. This gradually gets worse until 70mph is an absolute maximum and on idle its a shuddering wreck.

Heres the kicker! Pull over, ignition off, then start her up again and its fine again, go back to before stage one! If kept below 3k or 50mph  it doesn't recur either! Felt like coil pack hg and by leads all at once. Is this a known phenomenon? It's ky first fly by wire in a mig but I have a complete y26se at home if spares are read!

Any thoughts?
Regardless, its done 400 miles home and its a lively example!  Will take some pics shortly!

[Andy H]

What comes up when you do the pedal trick ? Paperclip Test and Pedal Trick

[joshwyatt]

As Andy has suggested, the 'pedal trick' should yield codes that will help you. I would be expecting a 0300 and single or multiple 030x (i.e. 0301, 0304) These relate to a missfire.

I am to be in Bath at some point on Sunday to collect some items, whilst I am no mechanic, I know enough and would be more than happy to look at the vehicle if you're about? Pedal trick will reveal codes, and my code reader can clear them so we can see what returns.

[feeutfo]

Almost certainly a misfire. Oil and/or water in the plug wells or just a degraded ignition system.

But check for codes as said. No code reader required for engine codes. Just the pedal trick.

[martin42]

check exhaust and make sure its not blocked 

[D]

As chrisgixer said, sounds like a misfire. Very likely a 0300. A scan tool might tell you if it is a specific cylinder that is misfiring.

[feeutfo]

Pedal trick will give cylinder specific info.
0301 = cylinder1
0306 = cylinder6
etc

But ultimately it's which bank you want to know. Diag of cylinder lay out is printed on the cam cover by cylinder 1, which is nearest the air box.

[jtypecav]

Thanks for the offer of help with the new purchase everyone!

Great to know other owners happy to help out too (I'll keep you posted Josh, than you for your kind offer!)

Pedal trick is a fantastic temporary out in the field whilst no laptop is available!

I'm getting 300 and 305 so that tallies with the help above, and I know which cylinder now too. Although would one  yl being out reduce the cars ability to maintain 60mph that much?

I definitely doubt it is oil build up as I literally can not state this enough:

If you go over 3k sustained doing 50mph the light comes on and it gets worse in two stages. Clutch in, off and on and you have bang loads of power again until you breach those precise conditions.  Accelerate hard from standing through the entire rev range (but below motorway speed)  and you don't get it either, so it's not load. If you off and on again oily plugs would still be oily and fluids still leaky but it's not. Its a fantastic up together wee beastie actually and I'm really happy you guys were on the money on the code front too!

[feeutfo]

It does sound very specific.

How old are the plugs and coil pacs, how many miles? Is the history known?

[jtypecav]

Only bought it yesterday so still going through the paperwork. She's a beauty though!

I think the issue is definitely ancillary not core engine functionality / mechanics if that makes sense. Engine bay looks very clean too and like it's had what it needs when it needs, but I'm assuming it could be due a coil pack or leads. Are there known issues with the management / ecu on the SE at all?

69k 3 former keepers, looks like it's had everything it is supposed to have had and most of it is at main dealers at full price too. New car smell makes my day every time I get in the bloody thing. Definitely a full omega convert!

[feeutfo]

No leads. 3 gang Coil PAC. See the tip on removing them in the guides section, they are easy to damage otherwise. Pot 5 being the easy side, so your in luck.

Wip the cp out, see what the plugs look like, any carbon scoring on the porcelain, are the plugs tight as they do come loose signified by soot around the base. Check cp for damage, splits, cracks, or split boots. ...IMO.

[albitz]

Blocked exhaust wouldnt give your symptoms imo.It has the effect of holding back throughout the rev range. Feels like a big hand has grabbed the rear bumper and is trying to stop the car from moving forwards.No misfire etc.
As said,sounds very much like HT trouble.Probably find evidence of oil or water in plug wells and.or rust damage to coil packs.

[jtypecav]

re. leads, of course - too used to my X30s.

Will take a look at the coil pack following the guides when I'm home on Monday and have some tools. I have another Y26SE in m
y old vectra I can swap some bits out on quickly to diagnose too. Will get a pic on the gallery!
 

[jtypecav]

Right! Changed both coil packs out today, and the plugs (had evidence of the water from skuttle ingress I've heard of) but there was no change.

Pedal test was only telling 1/3 of the problem.

Turns out, boot it to 4k once you loose cyl 4 & 6, repeat the "test" without clearing and you loose cyl5. even with new packs.

Changed out crank and cam for known good, no change at all either.

So tapped into ecu for traction control and get a couple unknown errors (one I looked up as torque control error undefined..) Cleared them, and they didn't come back although the problem persisted.

Basically it's coming down to traction control or abs or something. It is machine limited, it's precise and still clearable via ign. off and on again. Feels just like a non-fly by wire sl;apping your hands for using too much throttle and loosing traction. Except once it has, it forgets to let go!

Only thing that has me doubting this theory is that I'd have thought the FBW V6's would have used throttle not killing injectors off (which this problem is!)

Realising that the "2stages to this problem" for feel alone is corroberated against this as first bank goes then the second bank and only ever these cyls. It is so strange, but that legacy code of torque control is lingering in my mind!

Any thoughts?!

*Edit!* Changed the heater valve at the back of the top of the lump too as the diaphragm had perished and it was where I was loosing my coolant from!

[feeutfo]

It's a miss fire. The fact ignition off resets the fault proves it IMO. Or at least as much it can from the wrong end of a keyboard.
Once the ecu sees a misfire for long enough according to a set parameter it will shut that cylinder down completely. No fuel, no spark. Re start the car and the cylinder is live again, until the fault repeats.

Injector faults give cylinder specific codes too.

tc is so crude on these I very much doubt it's that.

What engine codes are you seeing?

What about plugs?