GTI revs dropping on idle

NMavs · Post by **NMavs** » Thu Apr 21, 2011 6:51 pm

Hi guys. From owning my GTI (over a year ago now) i have always noticed that the rev counter on idle tends to move up and down ever so slighty. Other people have said they noticed similiar happenings in their GTI's too. However, was sat at the lights the other day and the revs virtually dropped right down to maybe 300 rpm, engine made a strange knock noise then came straight back up to idle. I thought that was strange, and again tonight its done the same. Im wondering wether or not its an ignition coil on its way out? Engine does seem to be rocking quite a lot, so plugged VCDS in, but no faults are showing. Anybody expierenced this / or something similar? Any ideas? cheers guys.

Keeno21 · Post by **Keeno21** » Thu Apr 21, 2011 11:06 pm

1.8T GTi? Check the MAF...

BennoGTi · Post by **BennoGTi** » Fri Apr 22, 2011 9:41 am

Mine does this (maybe not quite as bad to 300 RPM), but I have a fault code on mine

Cam shaft over retarded or something, basically I need my cam belt doing sharpish

When did yous last get done? Could be something similar but with no codes?

matt_123 · Post by **matt_123** » Fri Apr 22, 2011 10:38 pm

mine does this too and its only a 1.6 sport , but mines also recently started to drop on revs at idle... wondered what it could be ? something to do with the cam belt?

NMavs · Post by **NMavs** » Sat Apr 23, 2011 6:04 pm

I wudnt of thought it would be cambelt related. If cambelt ever slipped, the engine would just go bang. Im thinkin its possibly a dodgy air mass, but vcds doesnt show any problems which just confuses me. Also, fuel comsumption has dropped big time. Just wonderin whether or not it would be worth tryin a new air mass. Cars just had a major service at vw so i doubt it has anythin to do with spark plugs or leads, etc.

Keeno21 · Post by **Keeno21** » Sat Apr 23, 2011 8:34 pm

A dodgy MAF doesn't always throw up a code of VCDS. I'd get it changed.

Gillen · Post by **Gillen** » Sat Apr 23, 2011 9:45 pm

Disconnect the MAF and take it for a quick drive...

NMavs · Post by **NMavs** » Sat Apr 23, 2011 9:50 pm

I did disconnect it, went for a drive and am unsure whether or not it was just in my head, but it did feel a little more responsive, and engine seemed to be idling a little smoother. It doesnt do it all the time, just every now and again. But the mpg seriously is crap. Went blackpool today, only 45 miles frm where i live, had just over half a tank. I did a steady 70 there and back, fuel lights now on

lol. I know these cars are quite thirsty, but to me, that just doesnt seem to add up. Its like you can actually watch the needle move

lol

Gillen · Post by **Gillen** » Sat Apr 23, 2011 9:55 pm

No idea

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