when you start it from cold, it cranks over for abit (i think could be due to the starter on its way out) and then starts but it doesn't like to idle steady and almost tries to cut out, if i rev it a couple of times it will then idle fine.

any ideas on this, is the long cranking when cold related to the idle problem.

could it be an air leak.

thanks stephen

Edited 16 February, 201214 yr by sgard

Yes, it could be an air leak on the inlet manifold, but it could also be (and most likely is) a faulty temperature sensor.

What it is probably doing, is 'telling' the ECU that the engine is hot, with the resultant reduction in fuelling. This problem will clear as the engine warms up.

Regards.

I had the opposite problem when the car was HOT! It wouldn't start. Turns out it was the cam shaft sensor that had given up. But the coolant temp sensor is what I'd be looking at 1st as said above :grin:

A faulty temperature sensor can have one of two (or I suppose, both!) faults.

One as described above, the other is the opposite way round, when the engine is hot, it 'tells' the ECU that it is in fact, cold, resulting in over-fuelling.

are the coolant temp sensors common on these cars.

it was only really bad that one morning, i'm guessing because it was really cold that day, its not been as bad since then.

I've got the same problem but I've changed the tempreture sensor twice thinking I was given faulty new parts but my problem still persists, I think it may be down to the map sensor/air temp sensor

well today i started it from cold and the idle was rough, i found that if i reved it, it would just cut out but if i just let it idle it would eventually smooth out and run fine.

i've also noticed if its left to idle for long time when warm i can start to smell petol fumes.

well today i started it from cold and the idle was rough, i found that if i reved it, it would just cut out but if i just let it idle it would eventually smooth out and run fine.

i've also noticed if its left to idle for long time when warm i can start to smell petol fumes.

Seems a bit common sense from what caretakerplus said only a couple of posts ago;

when the engine is hot, it 'tells' the ECU that it is in fact, cold, resulting in over-fuelling.

So that would explain the petrol smell would it not? I'd change the temp sender. Not expensive to buy, piece of piss to change, and will more than likely solve your problems.

where is the temp sensor located, is it in the rad.

thanks

On my car (not sure if it's the same on yours) there's a thick rubber pipe going into the top right hand side of the engine. Between the pipe and the engine there's a sensor clipped into place (it's round and mine was green in colour). It points downwards sort of towards the front bumper and is held in by a single clip which fits into the top.

Hope that helps,

I got this problem and actually in the summer now when i think back i was smelling petrol and this all explains things alot. my 6N struggles when the engine is warm but starts fine when it's cold so i am guessing the temperature sensor is always assuming the engine is cold

I will change the sensor but i got some question when everyone says "temp sensor" are they referring to the "intake air tempature sensor" ?

This http://www.eurocarparts.com/ecp/c/Volkswag...42a4&000572

Or is it a different temperature sensor we are talking about?

On my car (not sure if it's the same on yours) there's a thick rubber pipe going into the top right hand side of the engine. Between the pipe and the engine there's a sensor clipped into place (it's round and mine was green in colour). It points downwards sort of towards the front bumper and is held in by a single clip which fits into the top.

Hope that helps,

Are you talking about this rubber pipe?

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I would much appreciate as much information as you guys can give to help

So i was outside widdling around in the car and doing lots of research, think i have found it!

It matches the part on euro car parts, black with a yellow banding and 4 pins

http://www.eurocarparts.com/ecp/c/Volkswag...a100&000572

Took a pic to help others find it if needed

By mixmasterlooney at 2012-01-25

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Thats the beast.... i did mine.... so if i can do it, anyone can....

still got the same problem tho!!

Thats the beast.... i did mine.... so if i can do it, anyone can....

still got the same problem tho!!

Yeah for me after i changed the sensor the problem was still there, and i actually got the blue one instead, that is meant to be a newer one rather than the exact replacement, the black one with yellow band.

Anyways i disconnected the battery over night the same day after i changed the sensor, to reset the ECU, i also cleaned the throttle body the next day then connected it all up, problem gone for good, car starts first time everytime cold or hot engine without struggling

fixed the problem, it was the coolant temp sensor, replaced it and its now running fine, starts up and idles perfectly.