Is there a way to test the resistance of a glow plug without taking off the intake manifold and what not? What is the simplest way to achieve this process if I just want to test them to see if it needs to be done.

The reason I ask is that I am having a starting issue whether it is hot or cold and I am wondering if it is the glow plugs or not.

Edit: The car has 62000 on the clock and is a 99. So, another question is how long do those plugs last? TIA

I don't know about Mercedes but Ford GPs can be tested in place. Pull the lead going to the GP and put an Ohm meter from from the top of the GP to ground (head). 1 Ohm or thereabouts is good, open cct is bad.

When the engine is hot the GPs are not really necessary so it sounds like something else. Do you have any fuel leaks, places where air could be getting into the system when it is at rest.

IF one of the glow plugs are broken, the glow plug light will remain on while the engine is running, along with the check engine light. There is an easy way to see if the glow plugs are drawing any current but it's too risky explaining it. Gotta be shown rather than written.

Since you stated previously that the engines stumbles while starting I would asume that one of the glow plugs arent' working. Recently had the same issue with our '99 stumbling and then the glow plug light stayed on so it was obvious it was a glow issue. After replacing the glow plugs she started right up, although the check engine did last a few days or so and went away on it's own...

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'97 E300
'99 E300

But if it is the glow plug or plugs, why is it still problematic when it is hot? Although I must say it is easer to start hot than cold.

Even though my car even when hot and I try to start without letting the glow plug light go off completely it is a little harder to start than if I let it go off and then try. I've tried that theory before :-)

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#dieselFLEET
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'97 E300
'99 E300

So how long do GPs last on this car?

The general consensus is that they last approx. 40K

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#dieselFLEET
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'97 E300
'99 E300