good start in cold weather.... - PeachParts Mercedes-Benz Forum

dunl · #1 02-17-2006, 01:02 AM

I left my 300SD home in the unheated garage today, with temps reaching down to -26, and getting all the way up to -19 Celcius for an hour or so.

Hate the mileage I get on my Grand Cherokee, so I thought I'd check on how my Mercedes would start without being plugged in all day (trust me, the unheated garage can't be a big plus for her).

Anyway, I went out at around -24, and tried to start it - successfully. It did stall after a few seconds without the pedal pushed, but once I had it started and gave it one push of diesel, she kept going just a like the trooper she really is.

Guess what I'm driving tomorrow.....

Just goes to show that kept in good condition, these machines will run well for you. The PO replaced the plugs and battery just before I bought it.

pawoSD · #2 02-17-2006, 03:43 AM

And with 300,000 on it....wow. Great engine in that car!

Its slowly dropping outside, lows tomorrow through sunday are supposed to get down to -3F I get out of work around 12am tomorrow night, when its about -2 out, so I get to see if it starts. I am going to try to tap into an outlet in the parking lot of my work though. (they're on every lamp post and on each little "grass plot" thing throughout the lot) The question is if they are turned on, dead outlets = no block heater and trusting car to start at -2....I am confident it can though, it has down to -7 for me before....

Currently she's outside and plugged in.

(Low of 16 tonight) I like to keep the strain off the starter/engine if at all possible.

dunl · #3 02-17-2006, 10:59 AM

Quote:

And with 300,000 on it....wow. Great engine in that car!

Well, there's actually only 100,000miles on the engine since being rebuilt (PO never told me why it was rebuilt so early), and she's going to pass 309,000 today, but I figure for a diesel she starts very well.

I did plug it in last night, which gave the advantage of almost instant heat when I drove it in today. Nice drive too......I think the engine was reminiscing about those fine German winters back home.....

gatorblue92 · #4 02-17-2006, 11:11 AM

wow thats impressive... im a little worried about how mine will do in the cold since im bringing it up from south florida next month where it has resided for its entire life

sailor15015 · #5 02-18-2006, 12:36 AM

Quote:

Originally Posted by gatorblue92

wow thats impressive... im a little worried about how mine will do in the cold since im bringing it up from south florida next month where it has resided for its entire life

What's the condition of the plugs, battery, and starter? If its been in a really warm climate all its life, that first plunge in the cold will give you a wake up call to things that were fine in warm weather, but just won't cut it in the cold.

pawoSD · #6 02-18-2006, 01:13 AM

I've found that extreme cold starts are best done by glowing about 25 seconds, then cranking without pressing the pedal, when the engine starts "firing" and shaking the car a bit (shouldn't take long at all on a healthy engine, mine fires on the first or second crank usually), press the pedal about 1/4 of the way down, and it will start instantly. Cranking and shoving the pedal down prolongs the process because too much diesel gets injected and it washes the cylinder walls/absorbs all the heat, inhibiting combustion.

Tonight I got out of work, it was extremely windy, and 7F actual temp. Windchill is around -13, I glowed about 20 seconds, started cranking, it was firing from the first rotation, and after the 5th crank (now firing and shaking) I pressed the pedal, and vrrrmmm....came right to life. Total start time: 6 cranks and about 3ish seconds.

234,208 on the engine. Just gave it an oil change today too.

15w40 Shell Rotella, as always. It has a fair amount of blowby too, eh, seems to make no difference at all.

I got a jug of clear fry oil from Sam's Club today, even out on our porch where its about 20 degrees or less, its still very liquid! no chunks or solidifying issues, I got the jug so I can experiment once its a bit warmer out.

Pete Burton · #7 02-17-2006, 11:14 AM

This is going to sound pretty stupid, but....the other nght I was reading some of my owner's manual (because I was waiting to pick up my son at karate practice and I had nothing else to read). It stated that you should hold down the accelerator to start it below 0C, and also press it down 3 times first below 0F. It's been starting great wihout that - I thought that you just turned the key

So I tried starting the next morning at 7F by holding down the accelerator. It started so fast it startled me! well, duh!

Krueger · #8 02-17-2006, 11:30 AM

I have to agree with Pete. On cold starts in the morning I just put the pedal down as soon as I start cranking and that makes a huge difference in starting quick. On a different note, I usually don't plug in the block heater. Instead I have a small portable trickle charger that I'll plug in when it gets real cold out. Just my opinion, but a fully charged battery will start the car much better than a slightly drained battery (from the cold) with a slightly warmer engine. If need be - you can crank a lot longer faster which is obviously key.

dunl · #9 02-17-2006, 01:39 PM

Well, except for the door locks and climate control on this car (which are completely fu-barred and haven't been fixed by myself yet), this car was in excellent shape (so far, knock on wood), and I have to agree with the battery thing.

Brand new battery when I received the vehicle, and I went to a meeting for a few hours last Sunday with the lights left on. Started just like normal.

Good battery, good plugs - you should be good to go.

It's kind of funny seeing my thread right above the "70 degree days are back" thread. lol

rg2098 · #10 02-18-2006, 11:32 PM

7 degrees outside this morning and boy she didn't want to start, after 30 second glow and 120 seconds of cranking she fired. FYI heres what I have done to optimize starting;

0W-40 Synthetic oil
5 new glow plugs reamed out with new harness
Brand new MB battery
Battery terminals / ground strap / hot junction box all cleaned and conductive paste applied.

After 120 seconds I still wasn't loosing any cranking RPMs, but once it did start, I reved it slightly and it stalled out. Never had this happen before and the same happened on whunters car (after we got in started ).

Maybe I should install that block heater thats sitting on my desk

katja · #11 02-19-2006, 02:12 AM

Last night it got down to 15F here. So naturally I had to try this as well (since that's about as cold as it ever gets where I live). Well, it was closer to 30F by the time *I* was ready to go. Glowed for 30 seconds, fired in 4 revolutions, but was particularly smoky. So I drove around for half an hour and then decided to go up a long hill nearby (a great Italian tuneup hill). Had a Chevy dually with a Duramax on my tail and he didn't seem to be too happy following me. I got 3/4 up the hill before I had to gear down to second. That Duramax passed me like the hill was nothing and no smoke from it either. Oh well.

It was still pretty smoky when I got home. I've never done a diesel purge...maybe it's time to do that. Also, is it normal for an older diesel to smoke more at idle in cold weather, even when warmed up?

Oh, I also had a minor moment of envy the other night watching a TDI Beetle fire up on a 24 degree night after work, presumably on biodiesel (she had the big sticker on the back) after only about 2 seconds of glow time and a tiny puff of smoke....

But I'm not planning on trading my car in for a newer toy

-AC
'76 240D

Ara T. · #12 02-19-2006, 02:23 AM

Bastards... I wish we had some real cold weather where I live so I could see how mine starts... my 617 always starts instantly and idles smoothly immediately after... our record lowest temperature was 26 degrees in 1932.

dunl · #13 02-19-2006, 02:46 AM

Quote:

Originally Posted by Ara T.

Bastards... I wish we had some real cold weather where I live so I could see how mine starts... my 617 always starts instantly and idles smoothly immediately after... our record lowest temperature was 26 degrees in 1932.

If you were here, you wouldn't wish that. It's so cold here that the other morning I saw two cockroaches trying to jumpstart their mouse in the kitchen corner.......

Hatterasguy · #14 02-19-2006, 02:17 PM

20 degress this morning after it being in the single digits all night. The SD failed to start.

SOB I forgot to plug it in and didn't shoot it with starting fluid until the bat was getting weak.

The block heater and bat charger are working now, I am going to fill the freaken intake with starting fluid and crank the heck out of it.