treiberg

I have had an intermittent issue with this for a long time, but now it seems it is a permanent issue. The glow plug dash light will not come on, and vehicle will not start - so I am sure glow plugs are not getting any juice.

I have replaced the glow plug relay - no effect.

So what else can I troubleshoot? The glow plug relay has one big wire (probably the 12V line) and the connector to the plugs and then a smaller connector with two wires on it. I am guessing that the small 2-wire plug is what delivers the signal for the relay to come on, so maybe I should check voltages there? Does it connect back to an engine module? If the glow plug relay is good (which it is), then is the engine module the culprit?

Thanks in advance for any help!

EdzBenz

I can't really comment on the specific problem as I've never really had this happen.
I'd suggest going to the www.peachparts.com website and asking this question. There are a lot of dieselheads on there that may be able to help you.

Plutoe

Do any dash lights come on when you move the key?? Do your exterior lights work???

toby1

Does the engine turn over?

treiberg

Yes, dash lights come on, engine turns over. Everything is fine except that the glow plug light doesn't come on, and the glow plugs do not fire up, and therefore the engine just turns but does not start.

I know it is not glow plug relay because it is new. It is in intermittent problem that has gotten worse. It used to be that if we just left the car and tried it a few hours later it would sometimes start. But now I cannot get it to glow plugs to heat up no matter how long I wait or how many times I try.

Plutoe

There are many MY changes what is the VIN!!

toby1

If it's a CDi engine you don't need glow plugs to start unless it's really cold.

I have one glow plug out and it starts without waiting for the light down to 0°C. Is yours pre-1999?

Is there definitely fuel getting to the injectors?

gmphertford

More likely to be a fuel problem than glow plugs, poss air getting into system via pipes at pump or filter, you can look at the pipes while getting someone to crank it over

treiberg

No, it is a glow plug issue. If the glow plug dash light comes on, it fires right up. The problem is that the glow plug light on dash and glow plugs in engine to not come on, so engine will turn but not fire.

This is a 1997 E300D W210, pre-CDI, and will definitely not fire without glow plugs getting hot.

VIN is WDBJF20F2VA366836.

Plutoe

I would start to look at or diagnose the K40 circuit(passanger side)---fuses, relays bla bla bla--the juice for the glow plug relay(driver side) comes from circuit 30---However remember it all starts with the ignition module--when key is turned circuit 30 lights up

I have no idea how you will test the systems without DAS Xentry---Oh well

treiberg

Went out with my multimeter and did a little troubleshooting (see picture). I unplugged the control wires (two wire plug, a white wire and a brown wire) from the glow plug relay and switched engine on to check for voltage at this plug. I couldn't get any voltage there. When I look at the wiring that goes into this plug, it doesn't look very healthy. Looks like part of the insulation is broken down, so I might just have a bad wire. I tried to wiggle the wires a bit and plugged it back into relay and then got the glow plug light to come on! Engine didn't start only because my battery is too worn down for sitting for last month (charging it now). So I tried several more times to turn ignition on, and am getting it about 50% of the time. However, wiggling the wires on that connector seems to improve the chance of glow plugs coming on, so I might have found the issue.

So how would I repair the wiring/connector? It is right where it goes into connector, so don't think I can just remove bad section and splice. It seems like I will need a new connector and then have to cut old one off and splice wires. Anybody out there know the best way to do this?

Plutoe

If that is the problem,the connector and the female parts can be defined in EPC----it's a dealer item!!---just be patient!!

treiberg

Back to this issue again. Car has been running fine for several months, with only a few times where light wouldn't come on, but usually if we just waited an hour or two, we would finally get the glow plug light and then car would fire up. But now I cannot get glow plug light on and engine will not start without it. Here is a tally of what I have investigated:

-glow plug resistance appears to be fine, all in the 0.6 to 0.8 ohm range
-glow plug relay seems to be fine, at least I see it providing 12V to output blades when I energize it, and you can hear relay click
-replaced the K40 relay
-problem appears to be worse when engine or ambient is hot

The problem appears to be that the signal to energize the relay is not working. I cannot consistently get 12v at the two input wires to the glow plug relay. My understanding is that this starts with the ignition switch, but it is also enabled by the temperature sensor located under the manifold. I wonder if this sensor has gone bad...??

Also, I need to start the car to move it. So I figured if I just apply 12V to the input side of the glow plug relay, then it will pass power to the glow plugs and I will be able to start it after 10-15 seconds - sort of bypassing the electronics that send the 12v. However, when I do this the relay only pops on for 1-2 seconds and turns right back off again, not nearly enough time to energize those plugs to allow me to start. Is that relay somehow super smart and know that my 12v is different than the one from the ECU?

If anyone out there has some input, or can even provide a wiring diagram for a 97 E210 E300D, that would really help.

mtrevelino

Did you replace the wiring connector as shown in your February post? My wild guess in that it only does it when hot is that maybe it is a bad sensor that is saying the motor is hot and to not energize the glow plug circuit. The sensor may be located in the block somewhere in the cooling system.
To get the car started in an emergency, you could always spray a little bit of either (starting fluid) into the air intake, but some are against using this approach.
Good luck!
Mike T.

m2-b1

I know this was a long time ago but did you figure it out? I have the same problem. No glow plug light. replaced the relay and tested all the glow plugs. still won't come on. Battery has been tested and is good. I was told that the two wire connector is a bidirectional serial data link to the ECU and it is possible that it isn't getting a good connection.