Speaking of glow plugs....

When were the Great White North's engine's valves last adjusted?

They ought to be adjusted every 25K Kms (15K miles) or the engine will lose compression and be hard to start, especially in the cold.

I did them just over a year ago (when I checked my timing chain). Values were very good, little adjustment req'd. AJ UP HERE in the great white north (Molson, beavers, etc.)

Oh Yes????? Freely accessable?

DAS

For direct contact replace nospam with schmetterling

If the engine has done > 250K miles / 400K Km a compression check may be in order - nothing lasts forever, not even a M-B. Meanwhile, suggest you glow it multiple times before cranking the cold engine.

I have a similar problem on my wife's '81 240D. It simply wouldn't start for her the other morning so I pumped on the fuel pump a few times and it started right off. Thought the problem might be the secondary fuel filter so I drove it around to my shop, changed the filter, pumped fuel till the injectors squeaked, started it up and drove it back to my wife's parking spot, .1 miles. Next morning it refused to fire even once and this car always starts with a two second glow plug heat up and a touch of the key. Finally pulled the cover off the glow plug relay and the 80 amp fuse was blown. Drove my 300D to the dealer, bought two new ones and put the first one in. Tried to start with no success. Checked the new fuse link and it was gone as well. Did like the manual says and checked out the various terminals on the glow plug relay after pulling the connector plugs. Wasn't exactly sure which terminal they were referring to as #1 but assumed it was the one marked 15. Anyway, that terminal had only about .75 volts rather than the

12+ required. Assumed the problem was the relay, pulled it off, removed the four screws holding the top on but didn't notice anything that would indicate a really fried board. However, it did smell like it had absorbed a lot of heat at one time or another but feel that might be normal for a unit that has this much amperage run through it. Anyway, my next step is to install another relay to see if that solves the problem but was wondering what, besides the relay, would cause the fuse link to go so quickly. Any takers?

How good is the battery?

If it was weak would the amps through the link increase?

The battery was changed 2.5 years ago, to a new Interstate. The starter was changed at the same time. AJ

You wrote that the glow plugs' resistance was between 0 and .6 ohms. Zero implies an open circuit, doesn't it?

The GPs may have failed if these are other than Bosch or Beru GPs, even in their relatively short mileage use.

The Berus are good for 100K miles, in my experience with my '80 300SD.

Oops, T.G. ;-)

Open = "infinite" ohms. Short = "zero" ohms.

If it is shorted, it will probably blow the fusible link.

Cheers, WS

I would pull out the GPs and wire brush the tip every year. While they are out, it is a good time to measure the resistance. Failure mode is usually open (high impedance). After moving to California, didn't do that for many years. One year the car wouldn't start again and I pull the GPs out, 2 were open and 2 have high impedance. So one one GP was working.

"I would pull out the GPs and wire brush the tip every year. While they are out, it is a good time to measure the resistance. Failure mode is usually open (high impedance). After moving to California, didn't do that for many years. One year the car wouldn't start again and I pull the GPs out, 2 were open and 2 have high impedance."

Maybe I'm just lucky, but I never have done anything to mine and am only on my second set in a 25 year old car.

I just bought a set of 5 and am going to change them all....will let you know how things work out. AJ