Glow plug timer question. - Page 3 - PeachParts Mercedes-Benz Forum

Diesel911 · #31 11-10-2012, 09:57 PM

Quote:

Originally Posted by qwerty

I did not say that at all. But the concept does point to the logic of an increased glow period at lower temperatures. If only the light duration increased and the glow period remained constant, there would be little to no time left once the light extinguished.

But don't take my word for any of this. If the detailed description in the 617.95 Engine Manual doesn't make it crystal clear for you, I am certain that I won't be able to do any better.

People read the same things but come up with different interpretations of what was read.
I have read the Manual but from what I see in the area I live in and My Particular GP Relay My Glow Plug Light says on for 10 seconds or less but if I leave the Key in the Pre-Glow Position the total length of time the Relay is activated is about 30 seconds, reguardless of the Temp.

Diesel911 · #32 11-10-2012, 10:11 PM

Quote:

Originally Posted by kerry

Have you ever experienced a glowlight stay on anywhere near as long as the plugs are energized by the timer? I've had my 85TD at 35 below zero and the light never stayed on for more than about 20 seconds, if that.

In My case I was speculating the length of time the GP light could stay on in some extreme temp.
I never did believe that the GP light is a good indicator of how long you should Pre-glow.
In the exmple above you can see from your experience that the GP Lignt is not an accurate indicator as to how long you should Pre-glow.

I know even at about 42 degrees F on mine I start easier if I ignore the Light and just continue to Pre-glow longer.

Brian Carlton · #33 11-10-2012, 10:15 PM

Quote:

Originally Posted by Diesel911

I never did believe that the GP light is a good indicator of how long you should Pre-glow.
In the exmple above you can see from your experience that the GP Lignt is not an accurate indicator as to how long you should Pre-glow.

I know even at about 42 degrees F on mine I start easier if I ignore the Light and just continue to Pre-glow longer.

It all depends on the condition of the engine. Since the SD got the rebuilt head, the light is an accurate indicator of how long the engine needs glow to start. Even at very cold temperatures, it will fire right off at the end of the light. Sometimes, I'll play it safe and wait an extra ten seconds, but I don't honestly believe the engine needs it.

This engine has never failed to start in about one second, after the new head was installed, independent of ambient temperature.

It was, by far, the best investment I have ever made in the vehicle.

Diesel911 · #34 11-10-2012, 11:22 PM

Quote:

Originally Posted by Brian Carlton

It all depends on the condition of the engine. Since the SD got the rebuilt head, the light is an accurate indicator of how long the engine needs glow to start. Even at very cold temperatures, it will fire right off at the end of the light. Sometimes, I'll play it safe and wait an extra ten seconds, but I don't honestly believe the engine needs it.

This engine has never failed to start in about one second, after the new head was installed, independent of ambient temperature.

It was, by far, the best investment I have ever made in the vehicle.

Cool
I have never checked the compression on mine and it does not get very Cold in the LA CA area even in the Winter so I guess My Car is not the best example.

w126boulder · #35 04-06-2015, 01:14 PM

isn't there also a pre glow sensor on the thermostat housing, not sure if this might be the culprit but worth checking out