V70, Slightly Jerky when cruising

thepeteh · 23 Sep 2011 at 20:17

I've posted this on a volvo specific forum too just to get some ammo before it's taken in to the garage.

V70 t5, 02, auto

When cruising at a constant speeds, say 40 or anywhere upwards it seems, Feels like a slight (repeated) lurch/jerk. It's not a violent motion but noticable from 'normal'. I've done a quick google and came up with "Electronic Throttle Module"? Or could it be some sort of missfire? Spark plugs? It doesn't appear to do it when on cruise control on the motorway for instance so you'd think it may be an electrical gremlin?

Whaddya reckon chaps?

TIA.

mbmbmb · 23 Sep 2011 at 22:14

I'm having a similar problem with my 10 xc90. Took a mechanic out and he could feel it, but they couldn't diagnose it.

It's going back in on the 10th for a 2 day deep analysis. I might be able to tell you more after that.

mjt · 26 Sep 2011 at 17:27

I swear my Z3 does this sometimes when cruising in 5th.
It's so very subtle, but it's there.

Serpantine · 26 Sep 2011 at 21:08

Could indicate failing leads, plugs or at worst coil pack(s) i suggest changing the leads and see how you get on.

Normally, however, you would find this during heavy acceleration but i suppose at a constant speed and revs you'll notice it more in the subtle manner you mention.

chuffnut · 26 Sep 2011 at 21:53

I have a similar issue with my car , Ford Cougar.
It's only noticeable at at higher cruising speed's and is caused by the air conditioning clutch kicking in and out.
Could be the same with yours.

mjt · 26 Sep 2011 at 22:54

chuffnut said:
I have a similar issue with my car , Ford Cougar.
It's only noticeable at at higher cruising speed's and is caused by the air conditioning clutch kicking in and out.
Could be the same with yours.

There's an idea.

Minstadave · 27 Sep 2011 at 01:40

Could it be misfiring? A dodgy coil pack or spark plug?

Django x2 · 27 Sep 2011 at 02:53

This is the one thing thats plagued my E60 530d since i bought it. Continuos speed lurches whether on cruise or not. BMW said it was the exhaust particulate regeneration system and the made it cycle at stand still. It wasn't. I told themk it felt like a dirty MAF sensor and pleaded with them to change it using 50k services to replace air filters as an excuse. BMW changed the MAF, not done it since

Ezah · 27 Sep 2011 at 09:11

I had a similar issue recently with my CL.. they had a really hard time to diagnose it because the fault was pointing at the injectors but kept moving around the 12 Cylinders.. eventually another client brought a CL600 in and we swapped the coil packs.. that was it. Job done as soon as the part arrives,. Merc wanted a grand for it though, but I managed to get one for half price elsewhere.

I havent driven it yet to confirm all is sorted, but my garage were indicating a possibly gearbox problem was causing some vibration and jerking.. we will have to see after the new coil pack is fitted,

thepeteh · 29 Sep 2011 at 18:32

Missed the recent replies but thanks for the ideas. Had it in to my local Volvo Indi today, car wasn't giving off any error codes but they took it for a road test and thought the gearbox was to blame. They flushed the gearbox, refilled it with new fluid and added some sort of gearbox treatment. The problem has gone, for how long remains to be seen... Drives so much better now though all round. Happy.

Ezah · 4 Oct 2011 at 10:46

Luckily I had the same problem!
My Garage were transporting it to a gearbox specialist which would have been extremely costly, but dropped it off at the dealer on the way for a check. They flushed the GB twice and said the fluid was filthly, and the problem is gone now. But they still said another flush is needed in 2000 miles or so just incase.