It's too cold for the NC diesel to start - PeachParts Mercedes-Benz Forum

strelnik · #1 12-19-2010, 09:25 AM

I just brought the car back from NC, a 1991 350 SDL with 603.97 engine and it won't start. Did start yesterday and even once after staying off for several hoyurs.

The situation: 5 glow plug out of 6

NO block plug

strong battery

I'll try whunter's suggestion of using a hairdryer, but I need to find a way to heat the block so I can get it started.
Advice?
Thanks

tankowner · #2 12-19-2010, 10:25 AM

Quote:

Originally Posted by strelnik

I just brought the car back from NC, a 1991 350 SDL with 603.97 engine and it won't start. Did start yesterday and even once after staying off for several hoyurs.

The situation: 5 glow plug out of 6

NO block plug

strong battery

I'll try whunter's suggestion of using a hairdryer, but I need to find a way to heat the block so I can get it started.
Advice?
Thanks

You didn't say how cold it is there - looks like average temp in MI is around 20F or so. You need to change out that bad plug (or do them all at once so you don't have to worry about it next year). If you had all good plugs you'd probably be running by now. Of course, being where you are, I am guessing you have plans to install the cord for your block heater.

I've been where you are before - had to use a heat source to warm the engine until it would start (same story - bad plug and freezing cold). The hair dryer sounds like a good idea - do your best to insulate and keep in as much heat as possible.

I now have all new plugs and Tank will will fire up pretty good down to about 15F without the heater plugged in. Although, I also have a heated garage now - so I don't even have to plug it in anymore. Good luck.

Edit: I guess I didn't say what I did - ran the car up on ramps and then placed a small propane heater under the engine. It was bitter cold that day and very windy. I placed some large sheet of cardboard around the car to try and keep the wind out. Terrible set-up just to get a car to start, but that's what one dead plug will do in subfreezing temps.

strelnik · #3 12-19-2010, 12:16 PM

It's alive!
The car just needed a friendly battery boost and after three glows, it started right up.
HOWEVER, it will now be moved to a spot that does not block traffic and it will be taken to winter quarters as soon as I can do that.

I need to study this engine before I do ANYTHING else.

I need the maintenance manual for these if anyone wants to give/sell me a copy/xerox/.pdf file

pawoSD · #4 12-19-2010, 01:22 PM

I just saw someone at autozone this morning with a 300SD 1991....it was white, and looked quite nice.

DieselPaul · #5 12-19-2010, 01:44 PM

My suggestion was going to be glow LOOOOOONNNNNGGGGGGGG it'll start.

babymog · #6 12-19-2010, 02:01 PM

A healthy 602 / 603 will not have any problem starting at 20F. The owner's manual suggests plugging the block heater in for starts below 0F/-18C, but above that it is not necessary.

My cars usually start pretty well around here (at a frequent 5F-15F in the mornings) without block heat, do chug a bit and smoke white but otherwise no problems starting when the glowplug light goes out.

Timing might be retarded, compression might be low, injectors might be cruddy / bad pattern etc., and most likely the glowplugs are weak and full of carbon.

Replace the glowplugs, get the engine good and warm and run it hard on the highway, see how it starts then.

The block heater is nice to have in temps above 0F, helps to reduce starter loads, give you toasty heat sooner, keep the oil cleaner, quiet starts. Synthetic oil is also a big help for cold temps to allow the engine to crank faster, start sooner, develop oil pressure sooner.

Junkman · #7 12-19-2010, 02:29 PM

Quote:

Originally Posted by strelnik

The situation: 5 glow plug out of 6
Advice?
Thanks

Seems like you answered your own question. These were expensive cars when new. The wealthy don't put up with cars not starting at 20*. Repair the glow system & see what you have.

strelnik · #8 12-19-2010, 02:34 PM

Quote:

Originally Posted by babymog

A healthy 602 / 603 will not have any problem starting at 20F. The owner's manual suggests plugging the block heater in for starts below 0F/-18C, but above that it is not necessary.

My cars usually start pretty well around here (at a frequent 5F-15F in the mornings) without block heat, do chug a bit and smoke white but otherwise no problems starting when the glowplug light goes out.

Timing might be retarded, compression might be low, injectors might be cruddy / bad pattern etc., and most likely the glowplugs are weak and full of carbon.
Replace the glowplugs, get the engine good and warm and run it hard on the highway, see how it starts then.
The block heater is nice to have in temps above 0F, helps to reduce starter loads, give you toasty heat sooner, keep the oil cleaner, quiet starts. Synthetic oil is also a big help for cold temps to allow the engine to crank faster, start sooner, develop oil pressure sooner.

Jeff,

the problem is solved. It's a nine-year-old battery that went down to 25% capacity overnight.

I charged it hard for four hours, it started the car like it was summer at 50% capacity.

Result: new battery asap. But the car is moved and the commuter beater is in position for work this week.

jfarmer64 · #9 12-19-2010, 04:36 PM

Had similiar issue in NC on Wed where the AM temp was 7F. Needless to say 300SD had issues starting with crappy battery that needed to be replaced. Called MB road side where they dispatched service tech to jump car. Talked with tech who shared that the older diesels (mine has over 240K) are very particular when it gets cold. He suggested to cycle the key 3 or 4 times to get the GP good and hot. If you can get a Block heater, go for it. It will not hurt to have that in MI, where I know it can get quite chilly (I had an 84 300D in Illinois and when temp was around 0, it would not start unless plugged in)

Hope this helps!

thayer · #10 12-19-2010, 04:38 PM

At twenty degrees, with no block heater, my 2 year old battery will give me One shot at starting. 1 full glow cycle, one cycle the duration of the light begin starting, slowly depress fuel pedal...it starts fine. If I don't do that pretty much exactly that way, then it will need help. to avoid that situation, I just plug the block heater in.

strelnik · #11 12-19-2010, 06:37 PM

Quote:

Originally Posted by thayer

At twenty degrees, with no block heater, my 2 year old battery will give me One shot at starting. 1 full glow cycle, one cycle the duration of the light begin starting, slowly depress fuel pedal...it starts fine. If I don't do that pretty much exactly that way, then it will need help. to avoid that situation, I just plug the block heater in.

The car is fine. I just need to learn more about it. Now that it's home, its maintenance can be baselined and everything that can be made predictable will be so made.

Obviously, the big culprit was the battery.