Excessive Pre heating/glow plugs

[asthpsw]

It hasn't caused me a problem yet...although frustration if I'm going out in the night on an emergency call.

Occasionally.....& the ambient air temperature can be 10-15DegC I get the Glow plug light on the instrument panel come on for 30 + secs, whereas last Winter when it was -5DegC or less it was only on for a fraction of the time.

When I do then turn the key to start, it starts OK but the "tickover" rev's are at 1100RPM (whereas on every other occasion its 900RPM) as I say this only happens after the excessive "Glowplug" light timings.

Added to the above I thought the glowplugs only came on at something like below 9DegC...& the time on was relavant to how cold it is.

Its a concern if the glow plugs are on for that length of time because of the excessive amount that they must be drawing from the battery.....plus of course is this a preamble to a bigger problem.....especially when it does start getting cold out ?

Paul

 

[Fidge]

It hasn't caused me a problem yet...although frustration if I'm going out in the night on an emergency call.

Occasionally.....& the ambient air temperature can be 10-15DegC I get the Glow plug light on the instrument panel come on for 30 + secs, whereas last Winter when it was -5DegC or less it was only on for a fraction of the time.

When I do then turn the key to start, it starts OK but the "tickover" rev's are at 1100RPM (whereas on every other occasion its 900RPM) as I say this only happens after the excessive "Glowplug" light timings.

Added to the above I thought the glowplugs only came on at something like below 9DegC...& the time on was relavant to how cold it is.

Its a concern if the glow plugs are on for that length of time because of the excessive amount that they must be drawing from the battery.....plus of course is this a preamble to a bigger problem.....especially when it does start getting cold out ?

Paul

I've just got an arosa and the bloody thing has packed in! In the rush to get it fixed I've just got my VAG-COM working! I noticed you are local to me so if you wanted help in diagnosing I could help you out!?

 

[basstard]

I had my idle speed at 1100 rpm when I had a temp sensor shot,,, I was told it was an "engine temp sensor",,, I don't think it actually exists but it happened at the very beginning so I knew nothing,,,

Does the car pulls more when the idle speed is at 1100 rpm?

 

[micky 32]

Check the coolant temp sensor.

 

[asthpsw]

Hi, thanks to both of you....
No it doesn't pull any better/worse indeed sometimes after using it it settles back down to 900RPM
It would make sense its a temp sensor as it is probably reading -20DegC for it to keep the glow plugs on for 30+ seconds !

On the subject of "Temperature" sensors has anyone disabled or recalibrated their "outside" Air Temperature sensor.....so that the Climate control works at temps below +5DegC.........I know why it prevents its use but then there might be a need for a shortwhile & if you use common sense you can decide to turn it off

Paul

 

[dmjw01]

No doubt about it - you've got a dodgy coolant temperature sensor. I had the same symptoms. Plug VAG-COM in before you start the engine in the morning, and it'll show that the coolant temperature is way below ambient - mine used to read substantially below zero when the ambient was around +15C.

Do you find that it starts with a bit of a "race" to 1500 rpm or so? Mine did.

If it's still in warranty then it's a simple and free job at the dealer's.