Slow starting - glow plugs?

[hagis]

My 1.9 TDi 100 has been a bit slow starting over the last couple of days. Usually it starts instantly, but it now requires the glow plugs to be held on for a second or less.

I'm guessing this is the glow plugs that need replacing (not the temperature sensor?). The car is 6 years old and I think it's still on the original set (I've not had them changed in the 1.5 years / 28k I've had the car).

Is this a big job for an amateur?

[adamss24]

My 1.9 TDi 100 has been a bit slow starting over the last couple of days. Usually it starts instantly, but it now requires the glow plugs to be held on for a second or less.

I'm guessing this is the glow plugs that need replacing (not the temperature sensor?). The car is 6 years old and I think it's still on the original set (I've not had them changed in the 1.5 years / 28k I've had the car).

Is this a big job for an amateur?
Glow plugs on VAG's Tdi are only energised when the ambient temp. is below 5 Celsius. I would change the Coolant temp. sensor as it retards fuel delivery and might put the pump timing outside the optimal starting window...They are not used every time like on a petrol lump. If you still want to replace the glowplugs, do it with the engine at 80 Celsius, otherwise you could break them while unscrewing...The head and the plugs are dissimilar metals wich expand/contract different at high temperature. Screw them by hand as its easy to strip the threads in the cyl head and torque to reccomended values.

[Turbokiisseli]

You can also measure the glow plugs to see if they're working with a Multimeter. Measure resistance against ground and see if there are big deviations. As I recall, on my old AFN engine the resistance of the plugs was around 1Ohm.

[hagis]

Glow plugs on VAG's Tdi are only energised when the ambient temp. is below 5 Celsius. I would change the Coolant temp. sensor as it retards fuel delivery and might put the pump timing outside the optimal starting window...They are not used every time like on a petrol lump. If you still want to replace the glowplugs, do it with the engine at 80 Celsius, otherwise you could break them while unscrewing...The head and the plugs are dissimilar metals wich expand/contract different at high temperature. Screw them by hand as its easy to strip the threads in the cyl head and torque to reccomended values.

Thanks, I'll look into that. The car has been starting fine up until the last couple of days and I never usually have to bother waiting for the glow plugs.

[hagis]

You can also measure the glow plugs to see if they're working with a Multimeter. Measure resistance against ground and see if there are big deviations. As I recall, on my old AFN engine the resistance of the plugs was around 1Ohm.

Thank you, I'll give them a check when I can get hold of a multimeter.

[natz]

Ive been getting the same problem, although i notice the car starts from cold easily on a hot sunny morning but when its a rain cooler morning then its not so easy to start ( bout 2-3 cranks ) i wonder if this is the glow plug or temp sensor?

[hagis]

Mine does start easier when it's been ran recently so I'm beginning to think it is the glowplugs.

I've got a multimeter now, so I might have a look at the resistance of the plugs and see if it's that.

[hagis]

Glow plugs on VAG's Tdi are only energised when the ambient temp. is below 5 Celsius. I would change the Coolant temp. sensor as it retards fuel delivery and might put the pump timing outside the optimal starting window...They are not used every time like on a petrol lump. If you still want to replace the glowplugs, do it with the engine at 80 Celsius, otherwise you could break them while unscrewing...The head and the plugs are dissimilar metals wich expand/contract different at high temperature. Screw them by hand as its easy to strip the threads in the cyl head and torque to reccomended values.

I had the plugs changed this weekend and the car is still a bit slow to start (compared to what it was like a few months back).

Is changing the coolant temperature sensor a big job? If it was on the way out wouldn't the temperature gauge on the dashboard be wrong as well?