Why won't this thing start??? - PeachParts Mercedes-Benz Forum

Orkrist2 · #1 02-11-2008, 01:44 PM

So, I drove my car all day yesterday, battery is charged, everything is in working order. Overnight we get freezing rain and its about 15 degrees. Won't start. Cranks and cranks. I let the glow plug warm till after the light goes out. I use the plugs a few times before cranking. I attach a booster charger with the jumper cable attachments. Its turning faster and souonds like its running while it cranks but it just won't start.

I don't want to run the battery down so I leave it alone, but I would like it to start hopefully by Wednesday! Am I missing something? Does this happen sometimes or is it a sign there is a wink link in the charging/ignition system?

Here she is today:

rrgrassi · #2 02-11-2008, 01:47 PM

Do you use a block heater? How fast does the engine crank? Cold engine and cold battery, coupled with slow cranking usually means very hard starting.

TMAllison · #3 02-11-2008, 01:49 PM

Pop hood and put a hair dryer in there on high and close the hood for 30 minutes. Also plug block heater in if you have one. If you dont, get one.

junqueyardjim · #4 02-11-2008, 01:56 PM

On most W123's the glow plug light goes out in 20 seconds. On cold mornings, use your watch. I know a minute is a long time if you are in a hurry and freezing. But if you want it to start, give it a full 60 seconds, then quickly off on the switch and give it another 30 seconds. Crank it up, and even after if begins to fire, keep that starting running right in there. If you can "rev" the engine up to 1500 rpm, let the starter rest. And I think you will be on your way.

vstech · #5 02-11-2008, 02:58 PM

Quote:

Originally Posted by junqueyardjim

On most W123's the glow plug light goes out in 20 seconds. On cold mornings, use your watch. I know a minute is a long time if you are in a hurry and freezing. But if you want it to start, give it a full 60 seconds, then quickly off on the switch and give it another 30 seconds. Crank it up, and even after if begins to fire, keep that starting running right in there. If you can "rev" the engine up to 1500 rpm, let the starter rest. And I think you will be on your way.

close, but I have yet to see a gp light stay on for more than 10 seconds, and the relay almost always drops out within 40, so if you gave it a full 60 you would likely have 30 -20 seconds of cooling going on... best to give it a 30 second glow, and listen for the thunk of the relay dropping out, then off and back on for another 30 seconds, then the instant the second thunk occurs, go for the starter and don't let up until you hear the motor pull away from the starter, sometimes it's good to give it about 1/4 pedal once it starts firing... not full throttle!

toomany MBZ · #6 02-11-2008, 03:05 PM

As vstech mentions, a full cycle times two. Also synthetic oil, proper valve adjustment.
You may want to check the plugs to see if they good.

wyrick · #7 02-11-2008, 03:19 PM

I agree. 5-40 Syn made a cold starts smoother for me. With my new GP's I can start down to about 10F without a block heater (I hate Chicago street parking!).
Just remember that the lowest temp overnight is what your block is going to be close to several hours into the day.
Take your battery inside, charge it if you can, and give it go later in the day. Good luck.

Stevo · #8 02-11-2008, 03:35 PM

Just one GP out can cause your car not too start, quick check...Pull cover off black relay, pull off square GP harness plug and check the continuity between ground and each plug wire. If one if different (no continuity) ...theres your "dead GP".

Lampbum2 · #9 02-12-2008, 02:20 PM

Put your battery charger on, make sure you have a good strong battery at this temp and you might want to put a small heater under your motor, but at this point it is your option.

Next while the battery charges, Check your glow plugs and make sure they are all good.
If they are all good make sure the battery is good and strong and cycle your plugs 3 times for 20 sec. each time, use your watch.
If the above doesn't work you will have to get a small heater under the motor and get it as warm as possible and repeat the above.

I had the same problem you had, one day it started fine got cold the next day and would not start, I checked my glow plugs and I had 2 that were good, I changed them all.
You should get some anti gel for your fuel if you are below freezing for long.
Good Luck! Jim

kerry · #10 02-12-2008, 02:25 PM

Check your glow plugs. If you dont' have a multimeter, a non-contact thermometer aimed at the plugs after they have glowed should show enough of a temperature difference to tell if one or more are not working.

MattBelliveau · #11 02-12-2008, 02:39 PM

Don't we all just LOVE cold weather???!!!!!

Stevo · #12 02-12-2008, 05:45 PM

Hes proly fired up and down the road, would be nice too find out whatz up.

Orkrist2 · #13 02-12-2008, 06:34 PM

No, not running. I'm at my apartment where I work (not where I live) so I have absolutely no tools or anything. Its OK. It should thaw by Thursday and then it will start I'm sure. It runs fine when it runs, but severe cold has always been a problem. I think I need to use synthetic oil for sure. Thanks anyways, guys, just wondered if there was a trick of the trade I was missing. I don't want to keep cranking it and run down the battery and so on. Oh well.

Stevo · #14 02-12-2008, 06:48 PM

Well heres hoping the weather warms up for you. I would check the GPs if you can borrow a VO meter and consider a block heater for future cold spells. My 240D wouldn't start the other morning and it was only about 30 degrees, a GP had died.