Block Heater: How Long To Leave It Plugged In? - Page 2 - PeachParts Mercedes-Benz Forum

JEBalles · #16 01-04-2010, 04:18 PM

In N.E. I've started my 240 down to the teens, but I've started plugging it in so I can reduce the cold running time. Especially with all the extra coolant lines for the V.O. it takes quite a bit to warm up.

As for wind chill, I thought it only affected wet objects, because the water evaporates with the wind, taking heat with it. Human skin I guess is damp enough to be affected. The engine should be dry, though, and not affected.

leathermang · #17 01-04-2010, 08:25 PM

' Wind chill' only affects things which produce their own heat.
Animals, humans.... it is the measure of how much faster that heat leaves the surface area of those heat producers compared to a no wind situation.

brandlj · #18 01-04-2010, 10:00 PM

I have 3 bad glow plugs on my 86 300sdl so when I get home from work, I immediately plug in my car and it stays plugged in and on all night long. When I leave at 6AM, my temp gauge is at 60 degrees already, and I really don't even need a glow cycle. Now when I leave work, I do chug a little for about 30 seconds because only 3 plugs are working. It also blows lots of blue smoke until it settles down.
By the way, I have INSTANT HEAT in the AM, NICE!!!!

t walgamuth · #19 01-05-2010, 06:31 AM

One hour is enough for me. As noted in the excellent post above, check your grounds. Functioning glow plugs are also essential. Wind chill may not affect final temp but it will drive all the heat out of your car that may have lingered so it does have an effect on starting. When it is really cold any weakness in your starting will surface.

Keep warm!

pawoSD · #20 01-05-2010, 07:02 AM

My dad just leaves his plugged in all the time.

I only use mine when its really cold (below 15F), but when I do its overnight.

300dOwner · #21 01-05-2010, 07:21 AM

Can't agree more w/comments making the car "cold ready"...last year (before glow plug change, battery and valve adjustment) I needed to plug it in 3-4 hours (on a timer) to get Ol Blue to start. I "tested" it this year when it was 9 degrees F. without the block heater, as I forgot to plug it in, and it fired right up w/NO complaint. A pleasant surprise.

Thinking that I'll continue to let the block heater 3 hours pre-dawn just to offset the cold start stress though.

Oh, the previous comment regarding unplugging the block heater is a valid one! It's dam embarrasing backing out of your driveway onto a road (in traffic) and having to get out and coil up 50 feet of extension cord ... Now how would I know that ???

Benzbeliever · #22 01-05-2010, 08:09 AM

You think that’s embarrassing. I made it all the way to town one day (about 30 miles of four lane traffic) before having someone flag me down. I had been dragging the 50 foot cord the whole way. I was kinda wondering why no one was riding my but that day.

Jeremy5848 · #23 01-05-2010, 12:54 PM

Quote:

Originally Posted by toledodiesel

I have an 87 300 sdl. Does this car have an idle increase on it and if so where is it.

Mike

Your OM603 engine has electronic idle control. There's a round plug (about the size of a quarter) with numbers on it, probably located somewhere on the secondary firewall, driver's side. Note the number, pull out the plug, rotate to a higher number, plug back in. Idle should go up about 50 RPM per number. The plug has a number of resistors to "tune" the ELR (electronic idle-speed regulating circuit).

The attached picture is from my 1987 300D Turbo (W124, OM603), a different car, but yours should be similar. (The picture is an old one from another project; it's the only one I have showing that plug.)

There is also a mechanical idle-adjustment screw on the fuel-injection pump but it should not need adjustment just because it's cold outside.

Jeremy

funola · #24 01-05-2010, 03:25 PM

I have found leaving the 400 watt block heater in my 300D plugged in overnight does make the engine start much easier in 20 F temps but it does not give instant cabin heat- 400 watt is not high enough for that. Plugging it in for 1 hour gives the same easy start so instead of wasting electricity I power it for just an hour before I need to start the engine..

buffa98 · #25 01-05-2010, 04:37 PM

I picked up an electirc timer from K mart. I set it for three hour before I leave. No issues starting down to 6f so far this winter. Also i run delo 15-40. Have not switched to synthetic yet, trying to find all the oil leaks first

t walgamuth · #26 01-05-2010, 08:17 PM

Quote:

Originally Posted by Benzbeliever

You think that’s embarrassing. I made it all the way to town one day (about 30 miles of four lane traffic) before having someone flag me down. I had been dragging the 50 foot cord the whole way. I was kinda wondering why no one was riding my but that day.

LOL! been there... now i always fix it so that it will unplug if I forget to do it.... I fix the cord onto something.

gvran71 · #27 01-06-2010, 01:25 AM

Plug it in all night here in Chicago. Wake up, crank the heat on and drive away without the cold diesel blues. Also noticed changing to synthetic tranny oil (PENTOSIN) helps immensely with the cold weather shifting.

gvran71 · #28 01-06-2010, 01:26 AM

95 E300D

barry123400 · #29 01-06-2010, 01:01 PM

Four hundred watts is about a nickle an hour operating costs if your hydro is about twelve cents per kw hour. I will not do the math but a timer in areas of long drawn out cold periods is worth the cost in my opinion.

Plus the lifespan of your block heater may be prolonged. You quickly become aware of the required run time to meet your needs. It also reduces much wear on the engine I would think. Even the starter and battery have an easier life.

Oldwolf · #30 01-06-2010, 01:49 PM

I run mine 1 to 2 hours before the morning start here in NC. It starts fine without the block heater but using it makes for a much quieter warm up...if you know what I mean. Plus the heat comes on much faster.

A cold diesel sure makes a lot of noise I find.