"Slow" plugs?

I have a '79 300D which is becoming increasingly harder to start in the mornings. I do not live in a cold area, infact it was in the high 50's/lo 60's today and it took a good 1 to 1 1/2 minutes of glowing before the light went out. Then I have to crank it for 10-15 seconds to get it to "catch". I have been told the glow plugs are fine as is the electrical, battery, etc. I've never had a Diesel, is this normal?
Thanks,
Joe

I had a '77 300D (same engine) and this seems a bit too long, to me. In the 50's the glow plug light should stay on perhaps 15-20 sec...if that. On my '83 300SD recently I had to use a wire brush clean corrosion off the negative battery cable and the terminal block where the positive cable distributes power to the rest of the car. Between your glow plug lag time and your starter cranking time, this would be the first thing I'd check. Otherwise I'd *guess* you may need a glow plug relay, but I'd check the terminals first. Cleaning them can't hurt.

The glow system should be ready in less than 30 seconds, so have it tested & replace those old glow plugs. Also a "reamer" should be used to clean out the G.P. holes while the plugs are removed.

What type of reamer should be used to clean out the glow plug holes? I heard of using a greased up drill bit and then cranking it with the plugs out...what is the proper tool and procedure?

Thanks

[Benzmac]

No drill bits please. Mercedes makes a tool that threads into the hole and reams at the same time.


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Benzmac:
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM