Wd40???!!!?!?!

[Bobby_Gaull]

OK, I know I'm pretty new to this ole diesel game but here goes....
as I've posted before I'm up here in Western Mass and it gets cold.
My '75 240d has been giving me trouble starting up in the morning. Sometimes it seems like it just does not want to do it. Its not the battery
(brand new Interstate 850cca), or the alternator(new since December).
I called my old mechanic in New Orleans who admittedly says he doesn't know jack about real cold weather. He says that I can get it to start by
spraying some WD40 into the air filter, directly into the chamber to the engine. This kinda freaks me out. I've heard something similar once before.

Please give me some definitive knowledge on this. I need this car to start reliably!!

ROB

[Brian Carlton]

You certainly can use WD-40 in an attempt to start it. It won't harm anything, but who wants to go through life in the winter running around under the hood with a spray can every time you want to take it somewhere.

I would investigate the glow plugs first off. Many of these vehicles have one or more than one glow plug that does not work properly.

Are you familiar with troubleshooting the glow plug system? There are about 100 threads on this very subject in the archives.

Edited: It is very important to understand that the glow plugs in that vehicle are different than most of the posts in the archives, due to the age of the vehicle. See post #11, by Palangi, in this thread. Special tests are required for series glow plugs. If one glow plug is bad, or there is a break in the wiring, none of the plugs work. Please advise if you need specific help with these tests.

Additionally, when was the last time the valves were adjusted and when was the last time the engine was checked for proper valve timing and injection timing? All of these items improve cold starting capabilities.

Of course, there is always the possibility that that 616 has a bit too many miles on it now, and is low on compression, but, I wouldn't bet on it until all other options have been exhausted.

[rg2098]

Glowplugs, valves, injection timing. To many good cars have been sold with "worn out engines" because one or more of these were wrong. There are plenty of threads in the archives on how to check all three.

When I was first looking to buy an MB Diesel, I found a '75 300D for $500. The guy said it would not run on it's own but he did run it on WD40!

Sure enough I cranked it while he sprayed and it ran for about 1 minute while he kept spraying!

[dieseldiehard]

this is about the only good use for WD40. The Ford truckers (pickum-up trucks) carry the stuff round for cold starts, its really oil you know.

Originally Posted by dieseldiehard

this is about the only good use for WD40. The Ford truckers (pickum-up trucks) carry the stuff round for cold starts, its really oil you know.

kerosene, really. Don't tell anyone.

[dieseldiehard]

Coal oil!!!!!!!!!!!!

[Carleton Hughes]

Paraffin!!!!!

[Wes Bender]

Boy oh boy, dieseldiehard, you is really old to call it coal oil. (flood of memories coming back on hearing that term). LOL

Wes

[whunter]

MSDS WD-40
http://www.wd40.com.au/trade_info.asp

Solvent naptha petrolium, medium aliphatic petrolium base oil as paraffinic distillate, heavy, solvent-dewaxed (severe) corrosion inhibitor unregulated, wetting agent unregulated, fragrance unregulated, carbon dioxide.

[Palangi]

75 240D = series wired glow plugs, therefore the instructions on glow plug testing do not apply and only add to the confusion. We need to do a detailed write-up on troubleshooting series glow plugs, both the GP relay and gorilla knob style.

[dieseldiehard]

I just look for either or both of these points when checking series connected Glo Plugs:
1) you look under the hood when starting at night and see the little zig zag wires glowing or
2) in the daytime you touch one of them and get burned BAD

[vox_incognita]

http://skinnerbox.steaky.org/Service/W123/w123CD2/Program/Engine/615/15-510.pdf
Hope that helps.

[stayalert]

propellant USED TO BE propane, perhaps "modern" WD40 is less effective?

[Bobby_Gaull]

this all helped. someone said up there that it could be the injection timing. Thats interesting. A mechanic in Brooklyn told me that one of my injectors was a bit off. Maybe I'll get the fixed in the next few weeks. I just was having trouble trusting his opinion because I'd already paid him a bunch and it was New York.

thanks everybody.

ROB