Glow time

Is there a way in VCDS to adjust the Glow Time. I feel I need a bit more than the 1-2 seconds I am getting. Two glow cycles seems to help, weather here hoovering around 0*C and can drop significantly.

I was under the impression that the light merely indicates when the glow plugs are fully hot, rather than when they stop being powered. Next time after the light goes out, don't bother cycling the key again. Just wait another 3-5 seconds and fire it up.

My wife will often turn the key on (on her PD TDI), and then before cranking the engine she'll adjust the radio, re-arrange stuff in the cabin (like gloves, etc), and will finally get to firing up the engine 20 seconds or more after the light has gone out. Works fine.

Interesting, I will give that a try. On my old GMC 6.5 the light is on when the glows are getting power.

The light comes on immediately on key cycle so those would have to be some pretty fast plugs.

I think the light is indicating that the plugs are operating and warming up but I don't have the manual here in front of me at the moment.

TDI Stevestr said:

The light comes on immediately on key cycle so those would have to be some pretty fast plugs.

I think the light is indicating that the plugs are operating and warming up but I don't have the manual here in front of me at the moment.

Click to expand...

I believe what he wrote but may not have been clear about was the light indicates they are active and warming up, once the light goes out then it is up to temperature but still heating (not sure on that part). So he is saying that if you wait longer even if the light is out the plugs are still active and warming.

one way to find out! can VCDS read voltages at the GP during start up?

I've been using the block heater (Canadian Cold Weather Package) and it helps with the how long the glow plug light is on.

But even when I leave the car unplugged I've never had any issues with start especially from temperatures as high as 0C. I did notice that the glow plug light stays on much longer the colder it gets.

http://www.dsd.go.th/itrain/km/kboc/2010_TestProject_WSC40/Automobile/DOC33_IL_40CA/DOC33_IL_40CA_1680_Diesel_Engine_2.0L_TDI_CommonRail_BIN5_UL.pdf

Shouldn't need much time...

“Spark engine” start at temperatures to –11.2°F
(–24°C).

Extremely quick preheating time. Within two
seconds a temperature of up to 1832°F (1000°C) is
reached on the glow-plug.

(Page 66 and 67)

Even with temps down to 4F degrees that mine saw last year, never needed more than 2-4 seconds on

link no worky

I'm pretty sure the light indicates when they're on (powered), but they'll obviously stay hot once voltage is removed since they get pretty damn hot. And from few cold starts I've done (~25°F), they will stay on longer than the normal 1-2 sec for a regular start.

IIRC the glows will actually remain on up to 17 seconds after ignition to help with pre-heat.

Unlike older diesel vehicles, light on does not necessarily correlate with glow plug on.

As a fellow Albertan, I understand the concern, but 41K later I've yet to have a rough start in cold weather in Edmonton, or Fort Mac, or Chetwynd, or Fort Nelson...

Mine always fires right up no matter how cold, plugged in or not. It is just if I start it right after the light goes out it starts and run rough for a few seconds. If I glow a couple of times it is better. So I am going to glow it wait 10 more seconds (key on) then start and see if it runs smoother.

The light is a suggestion, and does not indicate actual glow plug operation. The glow plugs will continue to run for a period of time even after the light has turned off. You can test this yourself by listening to the glow plug relay, watching battery voltage, or monitoring with VCDS.

VeeDubTDI said:

The light is a suggestion, and does not indicate actual glow plug operation. The glow plugs will continue to run for a period of time even after the light has turned off. You can test this yourself by listening to the glow plug relay, watching battery voltage, or monitoring with VCDS.

Click to expand...

What VeeDubTDI said. The GPs will stay on for a period of time after the GP light goes out. No need to cycle the key to get extra glow time.

Prior to 2002, VW used an electromechanical relay which you could hear click when the GPs turned ON or OFF. VW has been using a solid state GP relay since the 2002 model year, so there will be nothing to hear click on or off from the GP relay in a new TDI. The GP relay change coincided with the change from a 2-wire to a 4-wire GP harness.

One thing I like to do is watch the interior lights dim slightly when I turn the key to ON and the GPs turn ON. I can tell when the GPs finally turn OFF by watching for the interior lights to brighten back up again.