Glow plug delay?

[Lincoln]

Here's my bonehead question of the month (in that this is probably something I should already know, but don't): What is normal glow plug delay on our Passats? Meaning, at roughly what temperatures does there begin to be a delay at all before starting, and how long is the delay?

Having gone through two winters, I have never experienced any delay at all--I just crank it and go every time. Of course, I live in the Pacific NW, and garage my car, so it's rarely colder than ~30F when I go to start it. If I'm ever someplace really cold and the glow plug is needed, is it fairly obvious? I.e., will I not be able to crank the engine until I've waited a few seconds with the key in the on position? Or does the MFD say "please wait" or something like that?

It's not really a pressing concern, given that temps are still hitting the 90s around here, but I read another comment somewhere that made me realize I don't know what to expect. I assume I'm not doing anything "wrong" or causing any harm by not waiting a few seconds when it is cold out, since I've never had any problem starting my car, but please correct me if I'm wrong.

 

[Trvln Canuk]

My experience has been in -30c weather I have to wait about 6 - 8 seconds for the glow plug light to go out. The car then starts just as quickly as in the summer. I can also say from experience that at that temperature the car will not start until the light goes out.

 

[Palouse]

My experience has been in -30c weather I have to wait about 6 - 8 seconds for the glow plug light to go out. The car then starts just as quickly as in the summer. I can also say from experience that at that temperature the car will not start until the light goes out.

Just wait for the glowplug light to go out and fire her up.

 

[atc98002]

Since I have the pushbutton start, it of course waits until the plugs are warm before cranking. That said, I believe I noticed a slight hesitation last winter when leaving work in the afternoon. I too am garaged at home, so it's never delayed there. But after a cold soak in the parking lot at work it might take 1-2 seconds. Never more than that. My work building is in Renton, so temps can be slightly lower than closer to Puget Sound.

Of course last winter didn't have any killer lows, so not comparable across the country. Since we are in the same place, it should be worthwhile for you.

 

[JaredC01]

The glow plugs come on initially at 40*F IIRC. From there, the duration of the glow plugs change depending on outside temperature.

 

[wilder11354]

last winter here in NE Pa, had lows at -18*... cars not garaged, delay was about 6 seconds or so to start.

 

[VeeDubTDI]

3 seconds maximum, in my experience (down to -15F).

 

[1998redwagon]

varies with temp. in northern mn when the temp gets really cold (-40f) i have had to cycle the glow plug 2-3x to get the car to fire. unheated garage.

as it was explained to me the glow plug heats up the air in the chamber. glow plug turns off when the air temp reaches a minimum. when the glow plug turns off the walls of the chamber immediately drop the air temp below the minimum so that combustion doesnt occur if you attempt to start it. by cycling the glow plug eventually the increasingly warmer air heats up the first layer of the chamber until it can carry a compression explosion and away you go.