Anyone got any clues on this please?

On our way up to the Lakes last weekend for a weeks holiday, we stopped off for a break about 40 miles into the 300 mile trip. When we tried to set off again the car refused to start without giving it some gas - normally it starts first time, every time without anything more than a key turn. Car was last serviced in November 2009 by my local Skoda dealer.

I decided to continue on to the next stop before calling Skoda Assistance; once started the car was absolutely fine to drive. The man from the RAC arrived just 20 mins later and plugged in his computer - the only fault code found was for a heated windscreen - which I don't have! Weird.

Hetried several things but to no avail. He replaced the relay under the dash (fuel pump), mentioned a recall for Passats where the fuel pump fails (initially he advised I keep the fuel level above half way at all times), the battery was fine... he ran out of ideas. It seems the car would just start but the relay would cut out. At least this is what he came up with.

After a lengthy discussion with his colleagues the best solution was to continue onto our destination and organise a collection to my local dealer (20 miles away) and a loan car for as long as was needed. And for the remainder of our journey he advised not to switch off incase it failed completely.... made for an interesting time at our next break! As I set off, I noticed that the cruise control had stopped working also - coincidence?

Anyways, upon arriving at our cottage I happened to turn the car around so it was facing ever so slightly downhill - a very minor slope. The car started first time and continued to do each time I tried it over the next few days - not that we drove anywhere. Did this help to get the fuel flowing? I thought it best to get Skoda to look at it anyways...

So the car was collected on the Monday. Due to the remote location and width of the roads, I had to drive the car out to a suitable place large enough for the tow truck to get to it! I tried the cruise control - it too was working again.

A loan car was organized (Seat Exeo - very nice too - nice quiet CR engine note!) and I waited for the update from the dealer.

A couple of days later I got the call to say the camshaft sensor had failed - at least thats what showed on their computer. Cruise control fine also.

So my questions are:

What does the camshaft sensor do?

How is it linked to the starting problem?

How is it linked to the cruise control problem?!

And more importantly, why did the car start working all by itself if it was supposedly faulty? It doesn't make any sense.

Top marks to Skoda Assistance, the loan car company (Enterprise) and the local dealer (Telfords, somewhere on the west coast) in resolving this (all under warranty) but it would be good to understand what happened...

Cheers

Anyone? Please

Pretty please with bells on....

Q: What does the camshaft sensor do?

A: The Camshaft Position Sensor detects the camshaft position and it is usually used by the ECU in conjuction with reference to a Crankshaft Position Sensor.

Q: How is it linked to the starting problem?

A: The car should not start if the Camshaft Position Sensor is faulty.

Q: How is it linked to the cruise control problem?

A: Not sure that it is. Most common causes for the cruise problem is a brake light out or a faulty brake switch. Maybe they just replaced a bulb and didn't tell you.

Q: And more importantly, why did the car start working all by itself if it was supposedly faulty? It doesn't make any sense.

A: When the engine is stopped it heats up before it starts to cool down. This is because you are no longer pumping coolant and you have no air cooling except for the fans if they are on. This temperature rise is greatest when the car has been driven hard immediately before being stopped. Many sensors are temperature sensitive and may fail when hot. When they cool down again they start working again and often keep working whilst the car is moving.

Edited 23 March, 201016 yr by rwbaldwin

Sounds like a starter motor to me......

When they get warm and the battery is marginal,

you can have problems starting.........

Q: What does the camshaft sensor do?

A: The Camshaft Position Sensor detects the camshaft position and it is usually used by the ECU in conjuction with reference to a Crankshaft Position Sensor.

Q: How is it linked to the starting problem?

A: The car should not start if the Camshaft Position Sensor is faulty.

Q: How is it linked to the cruise control problem?

A: Not sure that it is. Most common causes for the cruise problem is a brake light out or a faulty brake switch. Maybe they just replaced a bulb and didn't tell you.

Q: And more importantly, why did the car start working all by itself if it was supposedly faulty? It doesn't make any sense.

A: When the engine is stopped it heats up before it starts to cool down. This is because you are no longer pumping coolant and you have no air cooling except for the fans if they are on. This temperature rise is greatest when the car has been driven hard immediately before being stopped. Many sensors are temperature sensitive and may fail when hot. When they cool down again they start working again and often keep working whilst the car is moving.

I think you have hit the nail on the head, cars nowadays with all their electronic gubbins rely on all the sensors to be working so that it knows that all is hunky dory and the engine will start, if the ECU is missing one of those signals then it will, for safety and engine longevity sake stop the engine from firing up.

Edited 23 March, 201016 yr by countryboy

Thanks chaps..

I'd go along with the theory if I'd allowed the car to cool down but I hadn't.. I literally got to the cottage, parked up, unpacked, had a quick gander around the place then went back to the car at which point it failed to start without some gas as per. So I depressed the loud pedal, it started, I reversed out and turned her around, reversed back in (so car was facing ever so slightly down hill) and switched off. It took a minute or two - so after this the engine would still be hot.... Then it started first time - and every time thereafter - as if the fault had curred itself.

The cruise control started working then too - well before the dealers got their hands on it.

Its still a mystery....

Anyone got any clues on this please?

On our way up to the Lakes last weekend for a weeks holiday, we stopped off for a break about 40 miles into the 300 mile trip. When we tried to set off again the car refused to start without giving it some gas - normally it starts first time, every time without anything more than a key turn. Car was last serviced in November 2009 by my local Skoda dealer.

I decided to continue on to the next stop before calling Skoda Assistance; once started the car was absolutely fine to drive. The man from the RAC arrived just 20 mins later and plugged in his computer - the only fault code found was for a heated windscreen - which I don't have! Weird.

Hetried several things but to no avail. He replaced the relay under the dash (fuel pump), mentioned a recall for Passats where the fuel pump fails (initially he advised I keep the fuel level above half way at all times), the battery was fine... he ran out of ideas. It seems the car would just start but the relay would cut out. At least this is what he came up with.

After a lengthy discussion with his colleagues the best solution was to continue onto our destination and organise a collection to my local dealer (20 miles away) and a loan car for as long as was needed. And for the remainder of our journey he advised not to switch off incase it failed completely.... made for an interesting time at our next break! As I set off, I noticed that the cruise control had stopped working also - coincidence?

Anyways, upon arriving at our cottage I happened to turn the car around so it was facing ever so slightly downhill - a very minor slope. The car started first time and continued to do each time I tried it over the next few days - not that we drove anywhere. Did this help to get the fuel flowing? I thought it best to get Skoda to look at it anyways...

So the car was collected on the Monday. Due to the remote location and width of the roads, I had to drive the car out to a suitable place large enough for the tow truck to get to it! I tried the cruise control - it too was working again.

A loan car was organized (Seat Exeo - very nice too - nice quiet CR engine note!) and I waited for the update from the dealer.

A couple of days later I got the call to say the camshaft sensor had failed - at least thats what showed on their computer. Cruise control fine also.

So my questions are:

What does the camshaft sensor do?

How is it linked to the starting problem?

How is it linked to the cruise control problem?!

And more importantly, why did the car start working all by itself if it was supposedly faulty? It doesn't make any sense.

Top marks to Skoda Assistance, the loan car company (Enterprise) and the local dealer (Telfords, somewhere on the west coast) in resolving this (all under warranty) but it would be good to understand what happened...

Cheers

Generally speaking if your car goes into limp mode then this will de-activate the cruise control I assume as some sort of safety feature to stop any engine damage. A common feature on a lot of cars these days.

Generally speaking if your car goes into limp mode then this will de-activate the cruise control I assume as some sort of safety feature to stop any engine damage. A common feature on a lot of cars these days.

Limp mode wouldn't prevent car from starting though.. And once started, the car was perfectly fine, other than the cruise control... And then this also started working.