OK I'm new here so I realize now I should have posted this in this forum. (I also should have read some of the other posts.)

Here it is:

"I just brought home my very first Mercedes. It is a 1974 240D. It seems a bit hard to start sometimes. What is the best way to test the glow plugs?

Thanks"

The reason I ask this is that it is hard to start. This is what I've been able to pull out of the forum so far by reading previous posts in order of execution (assuming a fully charged battery):

- check the glow circuit wiring, relay etc
- check the glow plugs
How much current should each one draw cold?
- check the valve clearance
What should it be for a '74 240d?
- if the above doesn't help, do a compression check
- replace motor

Does that sound about right?

Since the car is new to you I would go another order.... with the engine cold.... wash it... being sure there are no dirt dauber nests attached to the glow plugs which could be shorting them out... then go ahead and set the valves, probably putting a new valve cover gasket on just for grins..... and change the oil and filters, including the gas filters possibly three... one in tank and two up under the hood... then try to start it and see if you still have a problem,,, then start checking the glowplugs and their circuit.... then the compression ..... I am just speaking in general... don't know how many filters your car has,,, but be sure you find them all... Greg

Do you know what the valve clearance should be?

Someone will, but I don't for your car.... sorry, Greg

atk_man

I also have a 74 240 and here are the valve cleareance from the owners manual:

Valve clearance Intake 0.004 in (0.1 mm)
(Cold engine) Exhaust 0.016 in (0.4 mm)

Hope this helps.

Aazer