Stanforth

I own a 1984 300D Turbo that is refusing to start during the winter. The engine cranks, but will not turn over when our Ohio weather is really cold (<15 F). I am using diesel additive with every fill-up. The only problems I have are during very cold weather, otherwise it runs fine.

I keep the block heater plugged in overnight and when the car is home during the day. Unfortunately, it must be parked outside. I suspect that the block heater is not working. I can find replacement kits for $50.00 US, which seems reasonable. Has anyone ever replaced one of these and if so, are they difficult to replace and do you have any pointers?

Thanks in advance.

sph17

I had three W123, all had block heaters installed when they were new by the dealer. All my W123 went over 200,000 miles w/o ploblems with the block heaters, thats not to say you don't have a block heater problem.

Here are so other suggestions for getting a diesel to start on a cold day.

Use a synthetic light weight oil during the winter. When I lived in WV, on days like you have in Ohio I could start my diesel w/o plugging it in to keep it warm by using Molil 1 or Castol Syntec.

After your glow plug light goes out, you need to keep cranking the engine until it starts, even if it takes 30-45-60 seconds or more. Stopping and starting over again makes it harder to get it started the second try. Check anbout this in your Owners Manual.

You can add an in-line fuel heater. This dosn't help your starting problem, but once you get your engine started, it will keep the fuel from gelling in the filters.

You can use up to 50% kerosene to cut your fuel to made it flow in cold weather, but this cuts down on fuel economy as kerosene has less energy.

Another suggestion, that causes many arguments in this forum is to add one gallon of gas, to a full tank of diesel, to cut the fuel, and keep it from gelling.

Half fill your tank, add one gallon of gas, then top off yout tank, to mix the gas with the fuel. I have done this without problem in all my dieses, but others on this forum will argue very strongly against doing it.

Auto Parts stores sell a heated dip-stick for about $10, this would be an inexpensive way to heat your engine.

Stanforth

Thanks for the info. I did find some fraying on the block heater power cable, so I think I will replace that and see if things improve.

I do have a follow up question about excessive starting times. I have read some other posts that suggest letting a diesel engine crank for up to a minute on very cold days. Do I run any risk of damaging the starter by doing so? This is the first diesel I have ever owned, so I am still getting used to the unique qualities in a diesel engine.

Thanks again.

sph17

One would hope that if MB is reccomeding turing over the starter up to 60 sec or more, then they would make the starter strong enough to withstand this useage. I have replaced three starters on my three W123s, all between 150-225,000 miles.

Steve

BMARTIN

my 84 300d will start down to about 25f without heating the block. One thing most owners don't realize is that the glow plug relay stays on for several seconds after the light goes out . in cold weather leave the key on until you hear the relay drop out, then start cranking. I use a timer to turn on the block heater when it is going to be cold. a couple hours will always do it.