MK4 Golf TDI starts from cold with temp sender disconnected

[peteheat]

Hi,

I have a MK4 golf TDI (110bhp) on a 1998 plate that has problems starting from cold but not when warm. Glow plugs and battery are new.
When cold the glow plug symbol on the dash goes out just as quickly as when it is warm and the car struggles to start. However if I disconnect the coolant temperature sender the symbol stays lit for some time. When it finally goes out the car starts absolutely fine.
I assumed therefore that the coolant temperature sender is not working and bought a replacement. This has not rectified the problem and the car starts first time in the cold only when the sender is disconnected.
Does anyone have any ideas on what is causing this problem?

Many thanks in advance!

[andy-b]

Hi,

I have a MK4 golf TDI (110bhp) on a 1998 plate that has problems starting from cold but not when warm. Glow plugs and battery are new.
When cold the glow plug symbol on the dash goes out just as quickly as when it is warm and the car struggles to start. However if I disconnect the coolant temperature sender the symbol stays lit for some time. When it finally goes out the car starts absolutely fine.
I assumed therefore that the coolant temperature sender is not working and bought a replacement. This has not rectified the problem and the car starts first time in the cold only when the sender is disconnected.
Does anyone have any ideas on what is causing this problem?

Many thanks in advance!

i had the same problem, and i sprayed contact cleaner into the water temp sender plug as two pins looked rusty. it worked a treat.

[Crasher]

If you have a fault code read done you will find you have a faulty coolant temp sender code stored. Have this code deleted and see if this helps.

[Alex Himself]

Hi,

Wouldn't mind checking for rust with mine also. sometimes when cold it can struggle a little. Where abouts is the water temp sender plug? And, is it easy enough to just remove and plug back in?

Cheers

Alex

[andy-b]

Hi,

Wouldn't mind checking for rust with mine also. sometimes when cold it can struggle a little. Where abouts is the water temp sender plug? And, is it easy enough to just remove and plug back in?

Cheers

Alex

well i have an AHF engine in mine and it's at the right hand rear of the engine. (blue 4 pin plug in thermo housing). you just need to hold two clips on the plug and remove. easy to put back on too. mine was shait at starting when cold. took 3 or 4 turns. but since i done that with the plug it starts first turn when hot or cold.

[Alex Himself]

Andy,

Many thanks for the reply

Alex

[Alex Himself]

Had a quick look at this on mine and can't see a blue 4 pin plug. Should I be able to see this without removing anything?

Cheers

Alex

[andy-b]

Had a quick look at this on mine and can't see a blue 4 pin plug. Should I be able to see this without removing anything?

Cheers

Alex

yes its visible without taking anything off. unless you have a different engine type, but mine is an AHF.

[Crasher]

Alex, what year and engine is your car?

[Alex Himself]

Bora TDI 110bhp 1999

Cheers