I'm quite confident I don't need a block heater to start any of my cars in the coldest Rhode Island winter. But the heater works and the cord is installed on my 240D....so I thought why not? In terms of the heater coming on quicker, any of you notice significant benefits? I know it's easier on the engine and all...my main interest is my cold butt tomorrow morning....it will be 5F.

Thanks.

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 159k miles
06 E320 CDI "Rutherford", Black on Tan, 178k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 145k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 75k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

It was -4F at my house this morning. I had plugged her in last night, and she started right off with only 1 glow cycle. The previous morning, when I could not open the hood, it took 3 glow cycles, and she HATED it.

Just sayin.

Jon

I've started my W115 in the high 20s without heating. It took about 45 seconds and she lit off in high idle. She shook and sputted for a few minutes but didn't die.

It's garaged year round, but some winter weekends I can't take it out for a few weekends in a stretch. For those longer spells, I'll use the block heater an hour or two beforehand and glow for about 30 seconds and she starts and idles smooth save for "cold diesel clack". So the heater does make a difference.

My compression is 290-310.

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1974 240D "Boldie" 170K.- New timing chain/freshly rebuilt IP/replaced valve seals/injectors/upgraded stereo/new Bilsteins with Yokohamas/fresh paint and rocker panels plus lots of welds.

It was 5F this morning as well....my first opportunity to start the 240D on a cold morning. I let it glow for about 20 seconds and it started right up with absolutely no difficulty.

__________________
14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 159k miles
06 E320 CDI "Rutherford", Black on Tan, 178k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 145k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 75k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

I use my block heaters whenever its 40F or below. Much quicker start, less wear and tear by far, and heat almost instantly.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

Yes, it is easier on your Engine and Starting System if you use the Block Heater and your Interior Heater will be useful sooner.

The only negative to it is being plugged in gives someone a chance to drive off with the Cord still plugged in.
I know I would forget. I would have to put a Note on the Steering Wheel each time I plugged in the Block Heater to keep from driving off with it still connected.

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84 300D, 82 Volvo 244Gl Diesel

I use both block heater and trickle charger when we visit snow country in winter. Both cars will start in typical teens-twenties temperatures without but it's easier on the whole thing and you get heat that much sooner, as has been mentioned. I use a timer that turns on at about 4AM so the car is ready to go first thing in the morning.

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Unfortunately, the element is burned out on the 91....but I may hook up a cord to the 92.

__________________
14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 159k miles
06 E320 CDI "Rutherford", Black on Tan, 178k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 145k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 75k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

If you have the factory block heater, you get almost instant heat. A lower radiator hose heater doesn't supply heat as quickly.

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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

Never used the block heater on either of mine. Living in an apartment means having no place to plug one in.

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1981 Mercedes 300TD, 1994 Honda Civic Del Sol
http://mefi.us/images/fuelly/smallsig-us/67195.pnghttp://mefi.us/images/fuelly/smallsig-us/103885.png

Really? I've never had a lower radiator heater but I really haven't noticed faster heat in the cab using any block heater I've had. It helps with starts but it is not like the coolant ever gets close to operating temperature. I was never scientific about it but it always seemed to me to be no difference in getting heat in the cab. Now the Webasto's, that is a different story.

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2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD

That's interesting. On my 77 300d, you could hear the block heater boiling the coolant--it sizzled--and the vents would produce warm air immediately. Not fully hot, but warm. The temperature gauge would jump up once I turned the key on. It doesn't do that with a lower radiator hose heater.

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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

If the block heater is working you should hear 'sizzle' as it gets hot within about 10 seconds of it being plugged in (assuming the surroundings are quiet).

I agree that it makes a huge difference to the starting temp on the gauge. I as soon as I start up, the temp gauge needle my 300d is about on the lower bar. However, I don't feel the air coming out the vents is warm for a while.

I never had a rad hose heater but my w116 SD had the circulating Zerostart tank heater installed. That was the cat's pajamas, nice warm air right away.

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Mac
2002 e320 4matic estate│1985 300d│1980 300td
Previous: 1979 & 1982 & 1983 300sd │ 1982 240d

“Let's take a drive into the middle of nowhere with a packet of Marlboro lights and talk about our lives.” ― Joseph Heller, Catch-22

I tested mine once, just to see if it worked. After a couple hours the coolant temp was up to the first line on the gauge, which is usually about when I start to be able to feel heat from the vents. Mind, this wasn't in very cold temps (about 45F.)

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1981 Mercedes 300TD, 1994 Honda Civic Del Sol
http://mefi.us/images/fuelly/smallsig-us/67195.pnghttp://mefi.us/images/fuelly/smallsig-us/103885.png

1985 300SD
If I want instant morning heat, it will be plugged into a timer over night.
At 32° F ambient, when the ignition is turned on after using the block heater, the temperature gauge jumps to 40° C with instant warm air.

.

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ASE Master Mechanic
https://whunter.carrd.co/

Prototype R&D/testing:
Thermal & Aerodynamic System Engineering (TASE) Senior vehicle instrumentation technician.
Noise Vibration and Harshness (NVH).
Dynamometer.
Heat exchanger durability.
HV-A/C Climate Control.
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Technical Quality Auditor.
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1985 300SD
1983 300D
2003 Volvo V70

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