2005 V70 AWD - misfire at idle

Duncx · Post by **Duncx** » 31 May 2020, 15:34

Good afternoon peoples .... just looking for some pointers.

2005 V70 AWD 2.5 turbo with 335,000kms.

Car idles quite roughly and has thrown a CEL, I haven't had an opportunity to plug in VIDA/DICE unit yet to see what it says.

I did replace the ETM a little while ago as the car had gone into limp mode.

While I had it all apart to replace the ETM I noticed quite a bit of oil in the pipe from the turbo to the ETM. It's not blowing blue smoke under acceleration, in fact I haven't seen any smoke as I drive. The original ETM seemed ok and more covered in oil than anything else.

The car seems to drive smoothly when not idling. As I accelerate away from a stop it has a quick cough and a splutter and then drives normally although sometimes if I try and accelerate hard, e.g. entering the highway, I will get a misfire.

I wouldn't expect to see oil in the feed from the turbo to the ETM and so my current guess is this excess oil is what is causing the misfire at idle ... worse when under more load in drive with AC on.

Any pointers on where to start looking? If it were turbo seals I would expect to see a blue/white smoke out of the exhaust and a cloud behind me as I accelerated but I don't see that.

I have no idea on the past maintenance of the car.

Post by **chrism** » 31 May 2020, 17:54

How many km on the spark plugs and what kind are they?

Post by **- Pete -** » 31 May 2020, 21:43

Just one small note, the newer P2’s didn’t technically have an ETM, rather a ETA or electronic throttle assembly. Much less prone to failures than early P2’s.
Anyhow, some oil in the lower Intercooler pipe is normal. You’ll find it in all the pipes to be honest.
Don’t take it the wrong way, but you really need to have your diagnostics pulled up to see a clearer picture. Even a basic/cheap code reader can be very useful in determining items in need of replacement.

Off the bat though, I’d be looking first at ignition components - namely coils and plugs. Also I’d encourage you to double and triple check all your piping - from airbox to turbo, turbo to OTE pipe (over the engine pipe), OTE pipe to Intercooler hose, and Intercooler to intake manifold pipe. Vacuum lines are very important for a decent running turbo engine too.

Duncx · Post by **Duncx** » 01 Jun 2020, 10:19

Thanks for the pointers ...... I did change the plugs a little while back before the ETM/ETA failed thinking that the lumpiness could be those.

I will try and get time today to plug in the VIDA/DiCE unit and see what it says ..... got a little sidetracked by a lower balljoint going that I am hoping to replace this afternoon if it doesn't rain any more.

I love the car but damn is it hard work so far.

Post by **oragex** » 01 Jun 2020, 10:57

How is the PCV ? May also unplug each injector see if there's a faulty ignition coil www.youtube.com/watch?v=nDwtZCWU7u8

Duncx · Post by **Duncx** » 11 Jun 2020, 18:27

I had a little time to do some digging today .... probably cos I had to quit work early as the bugger was now misfiring a LOT and not just at idle.

Vida/Dice tells me I have a misfire at idle from cylinder 1 at startup ..... I pulled the plugs, they are new, and they are quite pale which I assume to be the car trying to compensate for the misfire in some way.

I also have "ECM-24B0 front heated oxygen sensor (HO2Ss) bank 1 faulty signal". Digging into this Vida/Dice says the readings between front and back should be within 0.03 .... mine reads at 0.01. I am taking this to be a red herring and being triggered by the car dealing with the misfire.

I swapped coil 1 with coil 5 and still had a misfire but now a code for cyl 5 ..... swapped 2 and 5 and now a code for cylinder 2 misfiring.

So I am off on the hunt for a coil pack tomorrow.

One other thing I noticed .... turbo to OTE pipe ... the connection at the turbo is squished and more oval than round .... is there supposed to be a steel insert in the plastic pipe? There is a steel insert at the other end of the plastic pipe where it goes to the intercooler. I did find a steel insert in the rubber connecting hose between the turbo and the OTE sitting there loose although it is too big to fit inside the plastic OTE pipe? I am thinking that there should be a steel insert ..... if someone tells that there should be then I will go and hunt a Covid free scrap yard for a replacement pipe.

Cheers, Duncan

Post by **E Showell** » 12 Jun 2020, 20:21

Not a steel insert, it's a hose clamp, I'm betting.

Duncx · Post by **Duncx** » 13 Jun 2020, 10:18

Replacing the coil fixed the misfire

Yay.

Here is a link to the pic of the OTP showing how oval it is ...... other end has a steel insert, this end has a steel insert sitting loosely in the rubber connector. My guess is the steel insert stops the pipe being crushed, as it has been, when the clamp is tightened up. The steel insert sitting loosely doesn't fit into the end of the OTP, too large.

https://www.dropbox.com/s/w0vv976abbgpf ... 7.jpg?dl=0

Thanks for all your help you wonderful people, Duncan