2003, 1.4 (100BHP) saloon, 37000 miles, dealer serviced.

Experiencing quite a violent engine stutter for non apparent reason - lasts about 1/2 -1 second. This is becoming increasingly frequent. The engine just seems to completely stop momentarily and then re-start. It's sufficiently violent to throw me hard foward in the seat belt.

Seems to happen iwhen the accelerator is depressed slightly following mild overrun in second or third gear.

Sticky valve or OHV belt, blocked EGR, or EMU reset comes to mind.

Has any one else experienced this ?

Nick

Our 100BHP 1.4 Lupo did it once in a while. A throttle body alignment seemed to clear it.

Exactly the same symptoms occurred for me with the same engine (engine code AUB), I could be cruising at 60-70 mph on the motorway and then the rev counter would dip to zero for a second or so and there would be a retardation similar to firmly applying the brakes before everything returned to normal. This happened only once every few hundred miles but occurred completely randomly and was pretty scary. It also had a lumpy/hunting tickover, especially when the electrical circuit was loaded (power steering/air con etc.).

Anyway, as described above I had the throttle body cleaned and a throttle body re-alignment (needs VAG COM) at a local VW specialist (cost about £90) and it has been alright since then (touch wood). The throttle response is a lot more progressive now as well (i.e. there is at least *some* power now below 2500 rpm). It is also worth taking off the engine cover and cleaning the breather hose than runs along the back of the engine cover - there is some kind of valve where the up-pipe section of the breather hose joins in which gets clogged up. A bit of redex or similar with an Italian tune up wouldn't hurt either. Keep an eye on the oil consumption/spark plugs as well since the inlet system getting clogged with oil could be a sign of the piston rings wearing.

Mines a later engine code (BBZ), which according to the literature is immune from piston ring wear. Ha !

After reaching 25,000 miles the thing started consuming oil like no tomorrow (Currently uses a litre of 15-40 every 1300 miles, which is within the limits stated in the handbook !) and I had EMU lights come on a couple of times.

Dealer took a look at the EGR orifice, as blockage of that is the usual culprit and reported it clean as a whistle. Fault codes were reset. Then, nothing for the next 18 months, except this occasional stutter.

Progress eh ! My old VW Golf Mk I ran to 75,000 without using more than a thimble full of oil between services.

I've got the Ross Tech Diagnostic kit so I will have a look this evening for fault codes.

My worry is that using this much oil is bound to stuff the catalytic converter.

Nick.

Clunkclick - how have you gotten on, any closer to a diagnosis?

Haven't had chance yet to do a scan. Will try and do this evening.

I'm beginning to suspect that Electromagnetc interference is the problem, as the most recent car events happened within 100 yards of my home and , I'm sure that's its no co-incidence that recently I've been getting un-prompted machine resets on the computer and the TV digital box at home i.e. both screens instanteously go blank and reset the system boards.

I do recall amateur radio enthusiasts reporting some time ago (1990's) that they had observed BMWs on motorways suddenly lose power when they pushed the Push-to-transmit button on their amateur mobile radio handsets !

Interestingly, the system error reports from my desktops's Windows XP, immedately prior to the computer resets state that the system lost communication with the keyboard and mouse, both of which are wireless.

That's got to be massive pulse of EMI, as both items are positioned not more than 6 inches from the transceiver that connects them to the main board ! Also, my house has double skinned walls, tiled roof, double glazed windows with metallic coated glass.

In the past, in this locality, we did have problems with local taxi firms and I think they got a visit from the Radio Communications Agency, and for a while things were hunky dory. Of course, as soon as the regulators monitoring period expires, they probably turn up the power again. Being NW London, I don't think they are too worried by the rule of law and civic society, if you know what I mean.

Yet another case where the prospect of a quick financial killing via de-regulation has totally screwed-up the system, except for the .001% of the population making the quick profit !

Mind you, I suspect that there are plenty of other radio sources round here, apart from taxis, capable of producing a similar effect -The emergency services Tetra radio system, airport runway landing systems (I'm on the easterly flight path for Northolt), aircraft radar altimeters (I'm overflown by aircraft from Heathrow). The possibility of radar emissions from satellites has crossed by mind.

Worryingly, if it is a localised radio base station or even mobile radio that is causing this, their signal is radial, rather than directed, so everybody is getting a dose !

In the UK, any unwanted EMI emissions are probably all OK as the "Breach" thresholds are set ridiculuously high, even higher then the US - the UK standard radiation measure per sq metre, to which the regulator,the Health Protection Agency (Formerly the National Radiological Protection Board), controls things, are 4.25 times higher than allowed in the USA and 30 to 300 times higher than allowed in most europe countries.

I will continue my investigations and advise.

Nick