Hello all. My daily driver is a 1981 300SD. It has been running great, but it is not 'behaving' the same upon ignition. As you all know, the glow light usually comes on a few seconds in the 'glow' position, and then the vehicle can fire right up. Within the last few days, the glow light has not been illuminating, but the car firs up anyway. It's still in the 60's and 70's here in Alabama, but it's about to get colder, so I'm assuming I'll need to do something soon. Nothing has been with the glow plugs for the last ten years (had a mechanic replace 2 of the 5).

My question: Should I just bite the bullet and install all new Beru or Bosch GP's? Anyone have a preference between these two?

I am not electrically inclined, so even though I've read about checking out the resistance in each plug, I'm not comfortable with that at this point. Does anyone know where there is a step by step procedure (with pictures!) ? My wife says I'm good at following directions. ;-D

Any input is appreciated!

 

That link helps a lot!

Any suggestions as to preferred glow plug supplier - Bosch or Beru?

 

And Monark Glow Plugs.

If you are having a Mechanic do it be sure to ask him if he uses a Glow Plug Ramer to clean out the Carbon Buildup.

The Carbon Buildup allows the heat from the Glow Plugs to be conducted into the Cylinder Head instead of the Pre-combustion chamber. This puts more stress on the Glow Plugs because the Glow Plugs draw more amps when cold and less as they become red not.
When I tested a single Glow Plug (outside of the Engine) with an Automotive Dashboard type Amp Meter I foud it pegged the guage out at 60amps and a second are so later as it got red hot the amperage draw settled down to around 16 amps.

How Necessary To Ream Glowplug Hole?