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Hello All Polo Guru's
Please, i need some help with this a strange problem.

what it is, is a few days ago the car was stationary and idling, and then suddenly, the engine kept dropping from just under the '10' on the rev counter (which is where it normally is at idle) right down to near zero,and then back up, this continued to do this in pluses for about a minuet.

My mechanic said there was a tiny bit of carbon, which he cleaned, but he thought that wasn't enough to cause the problem, this happend a week ago.

Today i brought the car to him for the timing belt work, and this time while driving the car to him, it done it again, this time i was going around 20 mph, and the rev counter was droping from 20 going down to 10, again plusating between the two, this lasted about a minuet or two, no matter how far i pushed the gas pedal down.

I told him about the problem when i arrived, he said, it's difficult to diagnose the problem.

He kept the car to do the timing belt work, and had the car's ECU log checked by two different sources one by VW, one by 'Snap-On, in the fault log it had three errors, two were the first and second 'Lambda' sensors, and one was the water tenp sensor, so i had them all changed (bloody! expensive!)

I've had the car back for a couple of day's, and last night i started the car, let it idle for about 2 mins (it was a cold night), turned the headlights on, and drove away and the same thing was happening, when i arrived home, i perked the car, turned the headlights off but i could still see the rev counter going up and down as the sound of the engine idled up and down.

There was nothing to point to this problem directly in the ECU error log when the Mechanic had it recently, so, if having the ECU checcked again shows no issues, what could produce a problem of this kind?

Does anyone have any ideas what might be going on, and maybe where to look for the fault, the model of VW is below, and it's done 23,443 miles.


Your help at this fustrating time would be great

Kind regards
Livio

hey there man..
i had a simular propblem last week.. where the idle would hover way too high (around 1250) and then dip about..
check that your pcv hose is tight onto the bottom of your air box...

also, my problem stopped when i raced a 206, and revved it past 5,000 rpm:) haha
yea... i dont know why. but it worked fine after that

i had same problem and it stalled sometimes as well.. i took it garage and they replaced one of the fuel pipes and worked fine since

It could be a lot of things. Look for damaged/perished hoses. Failing that, you're on to shots in the dark. Of which, I'd probably go for replacing the fuel filter first.

Hello all, i think the third time the idling whent strange in my original post, i'd collected the car from him, but he couldn't change one of the Lambda sensors as he'd got the wronge type.

The problem hasn't occured again, once the other sensor was changed.

Just recently, about 2 weeks ago i gave the car a good hard run on the motoway, and had Cataclean' in the fuel tank, for me there is a definate improvment when it's used like this, a couple of days ago i filled the car up from near empty (i always use BP ultimate), and the car still feels good.