Plugs and injectors

[EMD]

Hi everyone,

I have a couple issues with my 1981 240d with 166,000 miles that I like your advice on before I order the parts.

It has a hard time starting when the temperature outside is 40F or less and also requires the pedal to be applied or it'll die right away. It smokes initially after start up as well. The glow-plug relay light lights up like normal but I don't think they are actually engaged and heating. I did just replace the glow plug relay. My other 240d, I would see smoke come from the glow plugs from heating all the oil debris. I believe this is a glow plug problem because once the car is warm, it starts right up.

I think I'm going to order new plugs and also change out the fuel injectors. I"m changing out the fuel injectors because I don't think they're injecting correctly with the smoke created at start up and the requirement to press the pedal when I'm turning the engine over to get it to start.

Before I go buying these parts, does this sound correct or like a waste of money instead?


Merry Christmas everyone.

[rocky raccoon]

Waste of money. Spend more time isolating your problem. Don't change your injectors --yet. Fix/replace one thing at a time. I know you are impatient but simply throwing parts at a problem is expensive and you learn nothing.

[Diesel911]

If you remove the Glow Plugs there is a reamer to get the carbon out of the glow plug holes or if you look in: Fast navigation Fast navigation Do It Yourself Links

I believe you will find alternative ways to get the carbon out. There is also a quick check to see if the Glow Plug resistance is what it is supposed to be but you need a Volt/Ohm meter.
However, that is not the definitive test for the pencil type glow plugs.

Bosch Glow Plugs (made in France or Germany not India) are entirely adequate and not expensive if you shop online. My way of thinking is that if you bought 4 of them and it turned out you did not need them it is not a waste to have extras on hand.
Having to buy a single Glow Plug locally could cost you as much as 3X the online price of one Plug.
However, the Injectors cost a lot more so deal with the Glow Plugs first.

As previously mentioned fix one of the issues then test. If you fix more then one thing at a time you won't know which fix to credit for the cure.
You probably know this but I am going to say it anyway. When the Glow Plug Light goes out you just keep the Key in the preglow position and you can continue to heat them till you hear the Timer Click and turn them off and then start. You can ever turn the Key off and back to the preglow position and start a whole new glow plug heating cycle.

[PaulH]

On my 603 I have to wait at least 5 seconds after the glow plug light goes out to get a quick smooth start. It's been that way since the car was new.

[sloride]

When was the last time you adjusted your valves?

[vwnate1]

As mentioned : #1 : adjust the valves first ! they need periodic adjusting and once adjusted need to be re checked at every oil change until they stop closing up then you can go to the 12,000 mile / annual valve adjust .

Tight valves cause hard starting due to compression loss, this is exacerbated by cold weather .

Go to F.L.P.S. / truck stop and buy a bottle of "DIESEL 911" and add the maximum dosage for your 18 gallon tank, do this when the tank is full or fill it right after adding the elixir .

On the top of the glow plug relay is a square MPC plug you can disconnect and use a simple test light to ascertain if each of all four glow plugs is a complete circuit .

As mentioned, don't replace them unless bad, if you can afford it replace all four .

DO NOT buy Champion / Autolite brand glow plugs ! they're worthless, often bad right out of the box and almost always fail in a month or so .

IIRC (possible, stop laughing) I used some Monark brand, German made glow plugs in my old NA 300CD to good effect and no problems .

I had a set of prefect used BOSCH glow plugs, oddly no one wanted them, not even free .

If your seat belt lam on the dashboard works, use it to time the glow plugs, it's *just* enough longer to ensure a rapid easy start .

It's not uncommon for the cold 240D engine to stall out if you don't use the fast idle knob .

Don't panic, look at the clear plastic fuel intake screen and see what's in it and what color the fuel is ~ if there's crud be aware the filters both need changing but let the Diesel 911 do it's job first .

Don't over speed the engine when it's cold ! give it just enough throttle to remain running, then fiddle with your set belt, radio and lights before dropping it into gear and moving off .

[t walgamuth]

Classic bad glow plug or two symptoms. I agree not to change the injectors premtively. Get them tested then make a decision.