Diesel experts: How important are the glowplugs when a 2006 CDI is warm?
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Diesel experts: How important are the glowplugs when a 2006 CDI is warm?
The glowplug light is lit for about one second even in the middle of summer when the engine is fully warm, and will start fine without waiting for it to go out. How important is it to wait? If not important when warm, at what temperature is it pertinent? I'm religious about waiting for the light, but others not familiar with diesels won't have a clue (valets, friends, etc.).
Any thoughts? The owner's manual is very vague on the subject.
Any thoughts? The owner's manual is very vague on the subject.
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Joined: Jun 2004
Posts: 339
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From: Michigan, USA
'05 E320 CDI, '07 VW Touareg V10 TDI, 2007 Porsche GT3
When we first got our CDI a couple of years ago, I tended to ignore the glowplug hold, as the car started fine without it. Then when cold weather arrived, the car would occasionally belch a cloud of blue-gray smoke on cold startup and run roughly for a few seconds. I puzzled out that this was happening when the ambient temp was 50F or below, began doing the one-second pause and have had no further problem. I think the engine was starting on less than six cylinders because I was skipping the glowplug pause, and the smoke was unburned fuel.
I doubt this hurt the engine, and it always started, so I'd not worry about valets or others not familiar with diesels. I think if the glowplug pause were critical, Mercedes would have built a delay into the startup routine.
This is all my surmise, so take it for what it's worth.
Regards.
I doubt this hurt the engine, and it always started, so I'd not worry about valets or others not familiar with diesels. I think if the glowplug pause were critical, Mercedes would have built a delay into the startup routine.
This is all my surmise, so take it for what it's worth.
Regards.
Last edited by khaug; Oct 17, 2006 at 09:35 PM.
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From: Houston, Texas
1981 300SD TurboDiesel, 1982 300D TurboDiesel
This is true for older models, not sure about the CDIs, but you'll get better starting in cold temps if you wait to start it after the glow plug light has been out a few seconds.
Senior Member
Joined: Jun 2004
Posts: 339
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From: Michigan, USA
'05 E320 CDI, '07 VW Touareg V10 TDI, 2007 Porsche GT3
