Glow plug light goes out within a few seconds
 

I am the new owner of a '85 300SD, 209k on odometer, and loving every minute of it!
As a new owner, I do have a few questions so please help me if you can.
First and foremost, this morning for example was 49f temp. when I started her up. I noticed that the glowplug light only stayed on for a few seconds before going off and then it was difficult to start. Would this be a glowplug problem or a controlling device problem? Also want to change oil right away, what is the best brand and weight to use?

thanks Jim H
 

I have worked on a lot of gas burners from general maintenance to engine rebuilds, never tried a tranny job. I have no experience with diesels at all, but I am ready to learn.
Thank you so much for your guidance.

:confused: Given the temp. of 49f for a cold start, should the glowplug light stay on longer or is that normal after sitting for 10 hours?

:rolleyes: Or...is the potentially bad glowplug the reason the light is not staying on longer? must be the latter.

I just replaced a problematic relay and I am upset to find that my light goes off almost instantly as well. I wait until the seatbelt buzzer goes off before turning over and it works fine. If you have a multimeter, you can see how long the charge remains on the plugs.

Thanks for your input. :) Tom

i would say that is normal for 49 deg F. if it was +10 deg F and the light went off after a 2-3 seconds only i would say that is not normal

as for engine oil you will get good value + performance from a dino 15/40 diesel rated oil like delo 400. you can easily get it in walmart in 1 gal jugs.
for filters you can click on the fastlane link above.

welcome to the forum.

You may be familiar with the normal mode of diesels whereby you start the engine as soon as the light goes out.

Now, this may be true for a Ford or GM, and it may have also been true for your M/B when it was brand new, but, don't go by the light anymore with an engine that has 200K on the clock.

I let the SD glow for about 15 seconds when the temps are above freezing. Down below freezing, I let it glow for 30 seconds. The light has turned itself off a long time ago. The benefit is reduced cranking time and an immediate smoother idle when it starts.

My light goes out after about 4-5 seconds when the temps are around 65 out or higher, today from a cold start I glowed it probably 5-6 seconds (started it right after it went out) and it started on the first crank and was running smooth right away. This is with 222k on the clock..... The 83's glow plugs are pretty much all shot (I think two of them work) and it starts wayyy less happily. It starts in a couple cranks but shudders and is upset for a second unless you give it a good rev, then its happy/fine/smooths out, however it still nails, which is why I'll be purging it. This week it gets glow plugs, a valve adjustment, and a purge, should solve all that.

If you've got a bad plug or glow plug system problem the glow plug dash light will blink after a few seconds in many cases. If it's not blinking most likely you have no problems with your system- glow as long as you like :D

How long will they glow after the light goes out?

They normally glow for about 35-40 seconds. The light has nothing to do with the glow time.

I was wondering about the time the light stays on. My light stays on for maybe 3 seconds and then I fire it up :) It's a little harder from a cold morning start as I am now running 80-90% wvo. It still cranks over within 2 seconds or so.

When I got my car (83 300SD) the light wouldn't come on at all. The glow plugs that were working heated fine. Found 2 bad plugs back to back in the firing order (1 & 3). Changed them (most parts stores can order them) and ther light started working. The car starts good right after the light goes out, even better if I wait an extra 5 or 10 seconds.

______________________________
83 300sd
3 Fords

I'll give it a good 20 second wait tomorrow morning and see if there's a difference on my wagon :)