Cold start procedure for a 1995 W124 ? - PeachParts Mercedes-Benz Forum

GregMN · #1 11-25-2011, 06:21 PM

A friend has a 1995 W124, 606 N/A engine with mechanical throttle control.
He will be parking it outside this winter in northern MN.
He does not have the owner's manual for his car.

I am looking for someone who has the owner's manual who can let me know what the cold start procedure is for that one year model car.

The procedures for the 2 different engines I have are not consistent.

The procedure for a 1996 w210 606 (electrical/drive-by-wire throttle):

Do not depress accelerator.

Run starter until it is firing regularly, but limit to 20 seconds.

If you stop the starting process before it starts, it may not start on subsequent attempts.

The procedure for a 1991 W126 603 (mechanical throttle):

above 32 degrees - do not depress accelerator
below 32 degrees - depress accelerator to floor
below 0 degrees - depress accelerator 3 times

Run starter until it is firing regularly.

If you stop the starting process before it starts, it may not start on subsequent attempts.

vstech · #2 11-25-2011, 09:39 PM

I would go by the 603 instructions, but:

in SUB-ZERO temps be CERTAIN before you crank that you have heard the glow relay come on , and come off, then kill the key, and check it again, and the INSTANT after the relay clicks off the second time you crank the key, and hold it until it fires, and be ready to give 1/4 throttle. it's true, if the motor does not catch and run after you let off the key, it's SUPER DIFFICULT to get the motor to start.
this is likely not the manual prescribed procedure, but it's the one best to use in cold weather on an older diesel motor. good glow plugs are very important here.

Chris W. · #3 11-25-2011, 11:48 PM

OK, you just made me go out to the car and get the manual. I quote:

Ambient temp above 14F (-10C). Do not depress accelerator. Turn key in steering lock clockwise to the stop. Release key only when the engine is firing regularly.

Ambient temp below 14F. Depress accelerator fully. Turn key in steering lock clockwise to the stop. Release key only when the engine is firing regularly and back off accelerator slowly.

Do not interrupt the starting process. If the engine is very cold it is possible that it will fail to start on subsequent attempts.

end quote.

I can tell you from experience that the 606 starts easily if your glow plugs are in good shape, even in very cold temps, and I also recommend your friend hook up the block heater which is no doubt installed, just to make it easier on the engine. It may need a power lead fitted, but if it's been a northern car most likely it has it already. Check behind the grill for a three prong plug.

When it is super cold I run through 2 glow cycles, you can hear the glow plug relay click off and do another cycle. Not sure it's needed, but I feel better...

Rgds,
Chris W.
'95 E300D, 355K

GregMN · #4 11-26-2011, 12:08 AM

Chris, thanks for taking the time.
My wife's W210 606 starts fine in sub-zero weather.

My friend has a block heater that he can plug in while parked at work, but just in case, I wanted him to know how to start the fire at 20 below.

vstech, thanks for your response too. It is interesting seeing the different factory recommended procedures. But, how cold does it really get down there?

vstech · #5 11-26-2011, 12:11 AM

cold? here in NC? I've not seen zero in a decade... however, I grew up in FRIGID Black hills SD... -100 with wind chills are not uncommon...

GregMN · #6 11-26-2011, 12:21 AM

Quote:

Originally Posted by vstech

....Black hills SD...

OK. South Dakota qualifies.

My friend will be in Hibbing, MN. He will see -35 to -45 air temp this winter. I live by the big lake, so when it is -40 inland, it's only -20 here.

vstech · #7 11-26-2011, 09:33 PM

yeah, it CERTAINLY qualifies... GASOLINE cars get frozen fuel systems there... that's cold!
we had to drain the antifreeze and bring it in the house to warm up on the stove, along with the batteries some nights... the block heaters would not warm the motor fast enough with the wind and the cold outside... only the cars in the shop/barn would crank.