My Octy has now covered 77,000 miles and has suddenly started running what can only be described as lumpy. It seems like it misses a beat every now and then. Nothing I can really put my finger on. The dealer said he could see what I meant but couldn't see any error codes and seemed to have no idea apart from an ECU update, which he said he did.

Well, it's made no difference. I thought it might bee the fuel, but I've filled up twice since it started happening last week.

Anyone have any ideas?

TIA

Steve.

Could it be since the hot weather of the past week or so?

I know my car ran like *** on the way home from work with the aircon on when the temp is over 22C - the intercooler is sandwiched between the aircon radiator and the engine coolant rad on the Astra, which heatsoaks the intercooler. Cleaned all the rads with an airline (must have been a bazillion flies stuck in them) and it's running a little better. Agressive remap + crappy standard IC + 22C + aircon = laggy smoky progress.

My VRS ran fine in the mornings and then like a dog in the afternoons pretty much every day last week.

I also got the DPF light up after spending a long time in traffic and mine's only done 21000.

I put the lumpiness down to the heat and the non-availability of any decent cool air (London driving) and the DPF light was fixed with a good thrashing down the Motorway!!!

Dual Mass Flywheel possibly.

Dual Mass Flywheel possibly.

Can the DMF make a car run lumpy.I would presume thats idle only:confused:

Can the DMF make a car run lumpy.I would presume thats idle only:confused:

Yep, throws the crank signal out and the engine ecu gets confused.

My 2.0 TDI has developed a 'heart beat' at idle, but not all the time, which is strange :confused: It's not a year old yet but I've covered 23,000 miles.

I have exactly the same problem as cj, except I didn't have to wait 23k miles - it was noticeable very soon after buying my 2.0 TDI, with only 10k on the clock. I assume that its full dealer service included checking engine settings and erasing bugs (literal and figurative).

Yep, throws the crank signal out and the engine ecu gets confused.

Mine's a late 06. Do they still suffer?

It's hard to describe exactly. It's a kind of hesitation. It feels like the engine is cold all the time and it's about to stall - It did stall once and I didn't expect that on DSG. After a long journey, you feel a bit seasick. Passengers notice it as well.

The dealer, Streets, Bristol wasn't really much help.

Can't comment on sea sickness, but I've been through a couple of DMF's :(

Very easy stalling seems to be one of the first signs of it going along with vibrations.

There's an article in this week's AutoExpress about very recent problems with the 5% biodiesel blend in filling station tanks which haven't been properly cleaned out for a while. Take a look - Biofuel bacteria wrecks engines

some pd diesel can get a problem on lekage injectors, make sure oil level not going up.