Just noticed my glow plug light doesn't light anymore. I am going to test the fuse, and then all the wiring to see if they are getting current. If not, then replace the plugs (the light could just be out on the dash... but i highly doubt that). The weird thing is though that my car starts after holding the key in the starter for like 3-4 seconds and having the idle knob all the way up. Is this normal of a healthy engine? I know it is probably not good for the engine, and i will diagnose it probably tomorrow, but i was just curious if this is normal for the engine to turn and eventually start even though the glow plugs light is not turning on the dash.

OR... will the engine never start without the glow plugs lighting, hence, the glow plugs are working (and the light is just out on the dash). Also i don't hear any noise indicating the glow plugs are charging. Because right now starting the car is reallly rough from a cold start.

-- Thanks

Likely one or more plugs are bad.

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 190D 2.5Turbo
1987 190D 2.5-5SPEED!!!

1987 300TD
1987 300TD
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

but the fact that the light does not turn on(and no buzzing sound)... would that signify that possibly some glow plugs are working?
Do all the plugs have to work for the light to turn on?

The Glow Plug Light Bulb is burned out on mine for over 1 year now and it starts normally.

You don't need a functioning Bulb for the Glow Plugs to work.

Do you have symptoms of a bad Glow Plug like rough idle; or does it start and run normally?

__________________
84 300D, 82 Volvo 244Gl Diesel

Have you looked at DJ GP repair?

Mercedes Diesel Glow Plug Repair


How quick are you to start the engine once you turn the key to the GP position?
Usually some where around 30 - 45 seconds the GP Relay will time out and you should hear a clunk when it turns off.
Or watch your Dome Light, it should get a bit brighter when the Relay turns off.

Turn the key to start and the engine should start running.
If it is rough till it warms up, you probably have a GP out, when that cylinder warm us, it will smooth out.

The GP`s do no make any noise when they are turned on. or Charging as you said.

When was the last Valve Adjustment? they may be out of adj and that can cause a hard start and roughness.

Turning up the idle knob isn`t a starting aid, it just speeds up the idle for a cold engine. No different that holding the peddle down some to start.
I`ve heard some novice Diesel beginners think it is a Choke.
Also pumping the peddle does not do anything, like you would do with a gas engine with a carb.

I agree, the GP Light being out does not cause a hard start.

Charlie



sent from my pos computer

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

The pin system basically uses one of the glow plugs as a temp sensor. IORC it uses number one for this. You can check the glow plugs with an ohmmeter from the connector at the relay, but that test doesn't mean much. Remove the number one,plug and inspect it. ,don't be surprised to find a hole in the shell.

In the days of these cars being current, these plugs only cost a couple of bucks each, so you just replaced them and solved your problems. At today's prices, it's worth removal and inspection first.

Hope this helps.

__________________
2001 SLK 320 six speed manual
2014 Porsche Cayenne six speed manual

Annoy a Liberal, Read the Constitution

so i did some more investigation and i took a 12v tester and saw that i was getting no power to any of the glow plugs. I did notice power was going into the glow plug relay. Therefore, i think i need to replace that relay.

Yes... it was running rough for about the first minute and then everything was fine. But is it weird that it started at all without any glow plugs??

I haven't replaced the plugs in a long time either, so i think i am going to replace the relay and the plugs.

Is it normal to have the idle knob in the most "open" position to start with and slowly turn it down as you start driving? I notice that starting the car without it fully open is almost impossible. (Granted... i have no working glow plugs atm).

Thanks everyone!

I just stumbled back to this thread 9 months later, you didn`t get your answer to your question.

Did you solve the GP or Relay problem?

No power to the GP`s sounds like your 80 amp fuse blew.
Pull off the relay cover and you will see the metal strip, if it looks good, may have a hair line crack.
Remove it and also see that there is no corrosion under the screws.

Check the small stuff first before condemning the Relay. A new relay is pricy.

The Idle Knob connects to a cable that pulls on the linkage to speed up the engine to warm it up.
Same as holding down the accelerator peddle to hold the engine at a fast idle.


If your thread works it way down to pg 2, type in Bump and that Bumps it back to the top.


Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

hahah yes. I ended up talking with my friend who is an electrician and we made a little gadget that acts as a manual relay. Was really easy to install, just need a capacitor, some wiring, electrical tape, and a press button. Now i can have my glow plugs light up as long as a i want!

I even connected the light so that when i press the button the glow plug light comes on.


the issue was a bad relay.

thanks for following up!

Is your 240D dark blue? The 82 in my sig I picked up a couple months ago,
it has a cobbled together manual push button for the GP`s.
The guy said his relay was bad also and went this route.

A used Relay from PNP is $10.

There is the Purple wire trick, that lets the GP`s stay on longer after the engine starts for quicker warm up and smooth the engine out.


Afterglow and the Violet Wire


Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works