So in fact something like this?
Technical Glow plug troubleshooting
- Thread starter nigelvan
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Technical Glow plug troubleshooting
See post #18
As you can read above, I was wrong. 5 times a 5 ohm / 5W resistor in parallel would give me a 25W resistor of 1 ohm. But I need at least 144W...
Thank you nigelvan, I'm going to try the 150W bit I posted above. Post #18 is not helpful in my case.
Hi,
In case it helps you.... a faulty glow plug causing the glow plug light to flash after engine starts does not stop the other glow plugs working.
Are you intending to cover up the fault? To fix later?
Keep in mind the resistor will get extremely hot , representing a potential fire risk/ personal injury risk .
J
I figure running with 3 out of 4 is fine - no need to fix but if I just leave it i'll be worrying others have/are failing and wont know till I'm stuck somewhere. OCD or just a worrier maybe. I don't plan on fixing it if I don't need to. Thanks for help.
Jack, a shorted plug will cause the relay to back off. I've tested this first hand. high resistance is not an issue but the relay will cut the power to all 4 if it senses a short... this is why I unplugged 2 shorted plugs in the past. Huge difference to have 2 glow plugs instead of none. But that was 4 years ago and now they had all died. Now I have 3 new and one snapped off old one. Still beats 0, or 2.
I am curious which one failed. Is it the right one? 3.0L or other engine?
I'm not sure yet. Part of the problem is that it is intermittent. This morning no error light are coming on - I noticed the glow plug light flash for half a second when I turned the ignition on which I think is telling me that no glow plug heat is required, so perhaps thats why, and measuring the resistance via the controller plug behind the headlight, G1 - G4 are all showing about 0.7 -0.8 ohms (allowing for my meter which says 0.2 when I test it with a dead short) which is annoying . I know they could still be faulty - the Multiecuscam says short circuit to ground when last checked. The 'check glow plug' message came on last night although it doesn't seem to show on first starting and didn't yesterday either, only subsequent when its been running, but not today! Typical.
Interesting, I never had working glow plugs, I bought it with the flashing light... I do know that if no glows are required I don't see any glow plug light on the dash. So I think if it does light up and doesn't blink it's actually powering the glow plugs as it should...
It's odd because the opposite of what you would expect seems to happen - this morning as per my post, it was cold and no lights. Then after my posting I went for a short drive, stopped for a few minutes and after that the lights and warning message returned when I started up yet by that point the engine was warm and you would therefore expect no call for heat from the glow plugs is required. Other people seem to have experienced the same, i.e. on lights on first starting up cold. I've started to strip things out of the way to see the plugs. Tomorrow I will pull the throttle body etc. out of the way (a real pain to do on the Euro5 setup) and try and get the lead off one of the plugs and check for a voltage drop. Unfortunately it will be cold again so the fault may not show initially. I'll report back.
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Hi Woodyvan. Glow plugs are usually rated at 11 volts, as there is normally some voltage drop from the feed wiring and current monitoring. With a resistor of 1 ohm, that means 11 volts at 11 amps which is 121 Watts. If you were designing for continuous operation you would need a 120 watt rated resistor, but in practice you can get away with a lower rating as its only on briefly. I used a 50 watt rated "Metalclad" type resistor (The gold coloured ones). Bear in mind that the 50 watt rating only applies if the thing is screwed to an adequate heatsink, so I used a section of U shaped aluminium extrusion a few inches long. With a fixing hole drilled in one end it can be bolted somewhere out of the way.
Regarding the warnings, the logic/programming seems to be designed so that there is no warning when a fault first occurs with a cold start needing glowplugs, but the fault is logged and the warning shown the NEXT time you start up, e.g. when you stop for fuel. If the fault goes away, or the weather warms up, after 5 or 6 starts the warning is no longer shown but the fault code remains stored.
Regarding the warnings, the logic/programming seems to be designed so that there is no warning when a fault first occurs with a cold start needing glowplugs, but the fault is logged and the warning shown the NEXT time you start up, e.g. when you stop for fuel. If the fault goes away, or the weather warms up, after 5 or 6 starts the warning is no longer shown but the fault code remains stored.
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Wouldn’t it be easier to change the glow plug?
I mean, they might not snap off?
I mean, they might not snap off?
Hi Anthony489. Thank you , I'm really grateful for this. I picked up a couple of 100W gold coloured ones today and a piece of aluminium heat sink which `i can see now is overkill. Thanks too for the explanation as to why it doesn't come on first start. I have ordered a clamp meter to check the amps drawn by each plug and try to see if one is faulty - they are a pig to get to just get to pull the leads on mine, never mind trying to get them out. And after 10 years in there and all the water that rains down on this engine from the ridiculous scuttle, I'm convinced would end up with a snapped plug. Googlebit makes a very good point - it might not snap, but if it does and a bit is left in there.... I like that less than a warning light and I really don't want to go down the road of getting it drilled out or leaving a broken bit in there as some other forums suggest.
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I couldn’t get to mine on a 2013 2.3 without taking off the inlet manifold. This included the connectors.
If you do have to take it off, be very careful of the plastic fuel pipes below, if you just try to push the manifold down, you can snap them, ask me how I know. :-(
I used a torque wrench in reverse set to 10nm, they snap at 20nm, I tested them in a vice. With a hot engine, they all came out thankfully.
Just make sure it is doing the regenerations properly, I was advised no glow plugs means no DPF regenerations on mine hence I did them ASAP.
Good luck whatever you decide.
Mine sounds the same as yours, the throttle body is mounted to a plastic looking inlet manifold which is in the way of the 2 middle plugs so I'm going to do the amp test at the connector junction which has just the 4 wires going to the plugs. Hopefully it is the far left or far right plug (G1 or G4 -I dont know which is which) at fault which I can get to with a bit more effort.I couldn’t get to mine on a 2013 2.3 without taking off the inlet manifold. This included the connectors.
If you do have to take it off, be very careful of the plastic fuel pipes below, if you just try to push the manifold down, you can snap them, ask me how I know. :-(
I used a torque wrench in reverse set to 10nm, they snap at 20nm, I tested them in a vice. With a hot engine, they all came out thankfully.
Just make sure it is doing the regenerations properly, I was advised no glow plugs means no DPF regenerations on mine hence I did them ASAP.
Good luck whatever you decide.
I've heard about the DPF connection and not sure about how to do a regeneration other than going on a long run which I have done a lot of in the last year diving back from Spain and France. Should that have done it?
I got them out on my 2007 van, at least 3 of them. One snapped and is now stuck. Of course the one right under the leaky scuttle. The connector was already rotten away so I was not surprised. the 3.0 will start at light freezing temps without the glow plugs, although a bit difficult. I had 2 working ones for a while and that improved it a bit. The 2 working ones died in the last 3 years as well so I had to do something... The one that snap probably snapped below 20nm as I was using my hand and a small 1/4" T-piece of 10cm in width. I thought it was moving and pooof, no warning.
For EURO 5 you will probably need the glow plugs for regeneration as already was mentioned: the engine will try to burn of fuel in the exhaust stroke in order to heat up the DPF to burn soot. Without glow plugs the diesel will stay unburned and possibly end up in the engine oil (at least some Volvo's suffer from this) and you might clog up the DPF. I have a EURO 4 so I'll get away with 1 faulty one.
For EURO 5 you will probably need the glow plugs for regeneration as already was mentioned: the engine will try to burn of fuel in the exhaust stroke in order to heat up the DPF to burn soot. Without glow plugs the diesel will stay unburned and possibly end up in the engine oil (at least some Volvo's suffer from this) and you might clog up the DPF. I have a EURO 4 so I'll get away with 1 faulty one.
