Left the 240D out last night to see how she would handle the 29*F cold weather. Man was I supprised. It started as if it had been in the garage overnight and it seen quiter, must be the difference of sounds reflected off garage walls. After the oil pressure came up, I put her in gear and drove off. Three blocks down the street I turned on the heat and would you believe warm air came out the vents, within 1.5 miles of the house at 35 mph the engine temp was at normal and the heat vents were roasting me.

My wife's VW diesel it would have taken about 3 miles to get warm air and 6 or 7 to get hot air out the vents. My '00 NB TDI was the same way as wife's Jetta TDI.

I'm wondering is this the difference in an all aluminum engine as in our VW's and cast iron engines in 123 cars?

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'10 Chrysler T&C Stow-N-Go White. Grandpa's ride.

'13 Chrysler 200 Touring Candy Red. Grandma's ride.

Age and cunning will always over come youth and vigor.

my experience has been that aluminum head like my 603 warms up much quicker than my 617 with cast iron.conversely the 617 will hold its heat longer and thats a definate advantage with overnight temps that we experience up here in the land of nanook

I would have thought the same thing, but had my doubts after the quick warm up of the MB.

The MB was outside for about 14 hrs before being started, so I doubt it had much residual heat left in the engine. It does have new water pump & thermostat that was installed last spring. But then in the summer the a/c would freeze you and give a guy an ice cream headach.

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'10 Chrysler T&C Stow-N-Go White. Grandpa's ride.

'13 Chrysler 200 Touring Candy Red. Grandma's ride.

Age and cunning will always over come youth and vigor.

No, the difference is not because of the engine materials. The TDI warms up so much slower because the computer controlled direct injection is so efficient that it doesn't make any waste heat.

Seat warmers are a must have in a TDI because the engine takes so long to produce any useful heat. My E300, on the other hand is up to 80*C within a mile.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

After I posted a few minutes ago it dawned on me what you just said in your post. The TDI engine is just very, very efficient at what it does.

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'10 Chrysler T&C Stow-N-Go White. Grandpa's ride.

'13 Chrysler 200 Touring Candy Red. Grandma's ride.

Age and cunning will always over come youth and vigor.

No doubt Rick is correct - the TDI electronically controlled engines are very efficient, more so that most any MB except maybe our version of the CDI engine.

That said MB has used a pretty neat trick to speed up warm-ups - the thermostat has a bypass function that circulates water in the block bypassing the radiator until the engine is at operating temp. I'm always able to get heat out of my 603 within a mile of start-up. I'm gratefull for this feature, I can't imagine how happy I'd be if I lived in Minnesota or New York.

My Dodge-Cummins pickup truck is the worst vehicle I've ever seen for warm-up times. Below 32F it takes about 8-10 miles of operation to get to any heat at all.

unfortunately up here in the land of the midnight sun.im going to have sacrifice some efficiency for a little more heat a little sooner.i see alot of tdi's running around here getting great mileage but id rather fight than switch.

Isn't this the neat little trick that ALL thermostats do in water cooled engines?

Please correct me if I'm wrong.

RP

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Rick
Avid Benz watcher

Previously owned 126's: 2 1981 300SD's, 1987 300SDL, 1991 350SDL,
Previously owned 123's: 1978 300D, 1983 240D, 1985 300D
Previously owned 124: 1994 320TE

Currently:
2004 Toyota Sequoia SR5 206k
2010 Ford Edge 122k
Always looking for the next MB diesel!

I thought almost no coolant moves (exception: little hole in t.stat that allows heated coolant to bypass the valve) until t.stat valve opens? BB

I am not too familiar with some of the other engines, but on mine the hot water for heating comes from below the thermostat (which appears to control flow to the radiator). The secondary water pump is what gives the heater the quick warm-up.

Quick warm up may be determined by where, in the system, the heater gets hot water from and whether there is a secondary water pump or not.

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Sam

84 300SD 350K+ miles ( Blue Belle )

240D's don't have this auxiliary water pump as they don't have the automatic climate control. My guess is that MB simply did their homework on getting heat into the passenger cabin quickly.

I'll second the Dodge/Cummins combo. I've actually travelled down a long enough downhill stretch, that when I pressed down on the accelerator at the bottom, the truck misfired and smoked like it had just been started up cold and flooded.

We know you set your wife's car that way just to deprive her of heat.

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You can get farther with a smile and a gun than you can with just a smile.

1984 300D
1985 300CD
1980 300SD
1993 SL500

My understanding of the difference between a bypass thermostat and a standard (?) thermostat is that with a standard thermostat, most circulation of coolant is inhibited at cold temperatures except for a small amount that goes thru a bypass hose. At temperature with a standard thermostat, full flow occurs thru the block and radiator.
With a bypass thermostat, at cold temperatures, there is full circulation of coolant thru the block and heater core. When the block heats up, the bypass thermostat activates and diverts some(most) of the flow thru the radiator.
The difference is in how much circulation occurs in the block at cold temperatures.

The Atomic 4 in my sailboat was built in two versions, standard and bypass. The bypass version is superior because it stops build up of crud in the coolant passages since there is full flow thru the block at all cooler temperatures. There is never a time at which the coolant in the block is mainly just sitting in place while the engine is running.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

Who me???

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'10 Chrysler T&C Stow-N-Go White. Grandpa's ride.

'13 Chrysler 200 Touring Candy Red. Grandma's ride.

Age and cunning will always over come youth and vigor.

Hmmm, the old VW Microbus had an optional gasoline-fueled heater that put out heat right away. I wonder if they still make those? I remember a brand called South Wind.

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1982 300SD