Diesel starting question

fuzzybunny · 02-10-2019, 12:15 PM

Probably the wrong place to post this but here goes.
So why does my 6 pot BMW diesel start first time even when its -5 degC outside?
How does it do that, I'm used to glow plugs and having to give a least few seconds before turning the engine over.

DriveS · 02-10-2019, 12:24 PM

They do have glow plugs. Mine pauses for a second, shows the heating element symbol before starting. Not sure what temp that is, but seen it a few times recently.

fuzzybunny · 02-10-2019, 12:31 PM

I wonder if the plugs come on when I get in the car close the door and the key is detected.

bishbosh · 02-10-2019, 12:32 PM

1. Direct injection vs the old swirl chambers of yesteryear.

2. Glow plugs that get very hot very quickly.

Hooded · 02-10-2019, 12:48 PM

I notice the 'pre-heating' come up on the display if I press the ignition on before starting the car in cold weather. Then when I actually start the car it starts instantly in around 1 second max.

mikeoz · 02-10-2019, 01:04 PM

I can recall the days when you got in a diesel turn the key then sit for 5 mins until the coil light went out...lol

Thank god those days are behind us...

Hooded · 02-10-2019, 02:33 PM

Quote:

Originally Posted by mikeoz

I can recall the days when you got in a diesel turn the key then sit for 5 mins until the coil light went out...lol

Thank god those days are behind us...

When was this.. 1950?

The longest I remember waiting before starting a diesel was when I borrowed a mid 90s Peugeot 306 diesel. You had to wait around 5 - 10 seconds after turning the key for the yellow light to go out before starting it.

djcowlin · 02-10-2019, 02:47 PM

Quote:

Originally Posted by doug_328d

Was just camping in -20F weather. Car started with no delay and no heat symbol. Does it have to be -50F to have the delay?

Camping during the polar vortex? Ouch.

Wills2 · 02-10-2019, 03:29 PM

Quote:

Originally Posted by doug_328d

Was just camping in -20F weather. Car started with no delay and no heat symbol. Does it have to be -50F to have the delay?

Who in their right minds would know? -20f is minus 29c and -50f is -45c that's not camping weather unless your surname is Shackleton or Watsey.

RickLS7 · 02-10-2019, 03:49 PM

Soul_Glo · 02-11-2019, 12:01 AM

:

Soul_Glo · 02-11-2019, 12:05 AM

Try -13. Not so instant. Last year in the Cotswolds is when I first read the preheating sign. It took about 30 seconds.

A mate still has an early 90's peugeot van I borrowed and he said it takes 2 minutes. It was slightly more but old glow plugs took an eternity to heat up.

kzg1969 · 02-11-2019, 12:43 AM

mines also paused for a second or so a few weeks back and it was only slightly below zero. Few days later the charge battery light warning came on. Not sure if its related though.

xenon · 02-11-2019, 12:52 AM

Quote:

Originally Posted by fuzzybunny

I wonder if the plugs come on when I get in the car close the door and the key is detected.

They do.

mikeoz · 02-11-2019, 07:49 AM

Quote:

Originally Posted by Hooded

When was this.. 1950?

The longest I remember waiting before starting a diesel was when I borrowed a mid 90s Peugeot 306 diesel. You had to wait around 5 - 10 seconds after turning the key for the yellow light to go out before starting it.

ok may be not a whole 5 mins but sure felt like it in an old 190D Merc...

HighlandPete · 02-11-2019, 08:04 AM

Quote:

Originally Posted by mikeoz

ok may be not a whole 5 mins but sure felt like it in an old 190D Merc...

Know what you mean.

Some of the old diesels were certainly 10 seconds or more to get sufficient glow plug heating.

Some of the old BMC diesels would then take another 10 seconds (or more) of cranking, to fire up, with a big plume of blue smoke.

Thank goodness we don't have CAV DPA fuel injection pumps these days.

Ridg · 02-11-2019, 10:38 AM

The leaky EGR is keeping the engine warm

02-10-2019, 12:15 PM	#1
fuzzybunny Second Lieutenant 112 Rep 289 Posts Drives: Orange F33 435dx Convertible Join Date: May 2011 Location: Somerset, UK iTrader: (0)	Diesel starting question Probably the wrong place to post this but here goes. So why does my 6 pot BMW diesel start first time even when its -5 degC outside? How does it do that, I'm used to glow plugs and having to give a least few seconds before turning the engine over. __________________
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02-10-2019, 12:24 PM	#2
DriveS Lieutenant 220 Rep 541 Posts Drives: F30 335d Join Date: Dec 2011 Location: Newcastle iTrader: (0)	They do have glow plugs. Mine pauses for a second, shows the heating element symbol before starting. Not sure what temp that is, but seen it a few times recently.
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02-10-2019, 12:31 PM	#3
fuzzybunny Second Lieutenant 112 Rep 289 Posts Drives: Orange F33 435dx Convertible Join Date: May 2011 Location: Somerset, UK iTrader: (0)	I wonder if the plugs come on when I get in the car close the door and the key is detected. __________________
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02-10-2019, 12:32 PM	#4
bishbosh Lieutenant Colonel 838 Rep 1,991 Posts Drives: F30 335d Join Date: Oct 2013 Location: Sheffield iTrader: (1) Garage List 2014 BMW 335d [0.00]	1. Direct injection vs the old swirl chambers of yesteryear. 2. Glow plugs that get very hot very quickly.
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02-10-2019, 12:48 PM	#5
Hooded Banned 1669 Rep 3,967 Posts Drives: F30 330d M-Sport Join Date: Apr 2017 Location: England iTrader: (0)	I notice the 'pre-heating' come up on the display if I press the ignition on before starting the car in cold weather. Then when I actually start the car it starts instantly in around 1 second max.
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02-10-2019, 01:04 PM	#6
mikeoz Major General 2856 Rep 5,607 Posts Drives: BMW X3 M40d LCI Join Date: Sep 2011 Location: cambs iTrader: (1)	I can recall the days when you got in a diesel turn the key then sit for 5 mins until the coil light went out...lol Thank god those days are behind us...
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02-10-2019, 03:49 PM	#10
RickLS7 Lieutenant 380 Rep 461 Posts Drives: F32 435D, Boxster 981S Join Date: Mar 2017 Location: Northamptonshire iTrader: (0)
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02-11-2019, 12:01 AM	#11
Soul_Glo Major General 13344 Rep 7,484 Posts Drives: G20 Join Date: May 2013 Location: Manhattan, NYC iTrader: (1)	:
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02-11-2019, 12:05 AM	#12
Soul_Glo Major General 13344 Rep 7,484 Posts Drives: G20 Join Date: May 2013 Location: Manhattan, NYC iTrader: (1)	Try -13. Not so instant. Last year in the Cotswolds is when I first read the preheating sign. It took about 30 seconds. A mate still has an early 90's peugeot van I borrowed and he said it takes 2 minutes. It was slightly more but old glow plugs took an eternity to heat up.
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02-11-2019, 12:43 AM	#13
kzg1969 Lieutenant Colonel 1299 Rep 1,924 Posts Drives: X3M Comp / M3 E93 Join Date: Nov 2016 Location: AberFreeze iTrader: (1)	mines also paused for a second or so a few weeks back and it was only slightly below zero. Few days later the charge battery light warning came on. Not sure if its related though.
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02-11-2019, 10:38 AM	#17
Ridg Lieutenant 205 Rep 404 Posts Drives: F31 330d Join Date: Dec 2016 Location: Kent iTrader: (0)	The leaky EGR is keeping the engine warm
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