12

Glow plug is merely an aid for starting the engine. There are many designs still produced today without any glow plugs (eg military diesels run without any electricity), and even many modern diesel engines can be started if glow plugs fail (unless onboard computer prevents that). Diesel's auto-ignition comes from heat generated by adiabatic compression of ...


6

When I was little, my dad had a yacht which had been a northern European coastguard patrol vessel. He bought it as surplus military and converted it into a yacht. The engine, a Stork Werkspoor diesel, well that was quite a story. It was massive, almost 6' tall, with a gigantic flywheel. Each cylinder had a shelf in the casting, on which you placed a blow ...


6

The way the VW (so assuming Audi is similar) glow plugs are controlled on the TDI Jettas of similar vintage, the plugs should come on (what VW calls "pre-glow") whenever the block is cold. You should see this in the instrument cluster as the glow plug light coming on briefly (only briefly, the plugs are very effective). The glow plugs then remain on (or come ...


5

A glow plug is essentially an intentional short circuit that heats up a wire and ignites whatever fuel is in or connected to the glow plug. Polarity rarely matters in this. But typically, the construction has the larger body as "ground" and the center pin as "vcc". There is an isolation ring that protects the two from each other, so current goes through the ...


4

I've not seen it done personally but I've been told that some old (WWII) military engines would be warmed up prior to starting in any number of ways which anecdotal included the use of lit marine flares. Apparently some Russian tanks with Diesel engines would be started by cranking them with Petrol engines or even warming them over a fire.


3

Yes, depending on the specific glow plug, this coloring is normal. Here is a link to a new BERU plug that has the same coloring in the image: http://www.autopartswarehouse.com/sku/Beru/Glow_Plug/W0133-1631189.html Here is a nice shot of a used glow plug:


3

Actually with modern engines, they can and do come on after startup. I think the reasons are spelled out fairly well in this article on Engine Builder Magazine: The government wanted to reduce the amount of diesel hydrocarbons and nitrogen oxide levels being emitted from diesel engines. Now, this is where the importance of the glow plugs comes in. Not ...


3

One possibility is low cylinder compression, either due to gases getting passed the piston rings or passed poorly seating valves. If gasses are getting passed the rings, this could possibly be detected by removing the oil filler cap while the engine is running, if you then put your hand over the filler and feel a large volume of gas being blown out of the ...


3

The answer was that the battery was bad. Apparently it was a cheap battery and the failed alternator drained it. Once it had been drained, it would no longer hold a charge. Replacing the batter with a new, good-quality (VW) battery fixed the problem entirely. One clue was that when I jumpstarted the car, all the symptoms went away -- no blinking lights ...


3

If there was any significant contact between the glow plug and the piston, I think you'd know it right away (horrible noise followed by horrible quiet). I'd double-check the glow plug wiring and electrically check the fuses -- fuses can fail without blowing, and the only way to know for sure is to check for continuity. I'd also suggest you double-check your ...


3

Since the starter picked up speed as you cranked, I would suspect bad connections from the battery down to the starter. I have seen this before and simply disconnecting the large cable from the battery to the starter and cleaning the terminals with wire wool and reconnecting them totally changed the speed of the starter. Also clean the battery connectors, ...


2

Glow plugs are not necessarily the problem. You said the engine turned over slowly. If turning was exceedingly slow then the battery would be more likely, not enough juice for the engine to gain momentum. If the engine turns over normally but just won't start, and when it does the start is "dirty", then the glow plugs are very likely. They aren't difficult ...


2

I don't know what was used before glow plugs. But you can use a hair dryer to blow warm air into the air inlet of a diesel motor and it will make it start easily in cold weather. I've done this many times and it works like a charm.


2

One method that is still used - but only on vehicles with metal air filter canisters is to remove the filter and put burning paper there - the hot air makes all the difference. Once running put the filter back in... Another method is to heat the air inlet pipe with a blowtorch again : metal not plastic... And yes I have seen both : heavy goods, ...


2

To expand on the answer above, many old vintage diesels ran a 'hot bulb' design. There would be a section of the head where an open flame would be used to heat it, so the engine could ignite the lower grade fuel oils/diesels without the need for extremely high compression.


2

If the compression ratio is high enough (around 22-1), there will be enough heat from the compression. Most diesel engines are turbo charged to increase power. The compression ratio is lower because the air is partly compressed by the turbine, but not while starting, so the glow plugs provide the extra heat needed.


1

My diesel runs the glow plugs for about 10 seconds, and I usually hit the starter at about 7 secs. They do go off after the light goes out, so cranking the starter after that tends to just flatten the battery. So it is better to re-cycle the glow plugs - a question of understanding the vehicle.


1

Your testing methodology seems pretty sound, the plugs definitely sound like they're shot. As you correctly say glow plugs should last a very long time, 3 years is just too short so I suspect one of two things, fortunately they are both simple and cheap: Faulty/mis-manufactured plugs: if you got a bad set of plugs they may burn out after way too soon a time ...


1

So took it to the mechanic indeed it needed a new crankshaft position sensor, after that was fixed they also found out one of the pistons were gone. Car is no longer driveable. There is a metal banging sound in the engine.


1

After confirming battery and cabling found loose control signal on starter, corrosion on several grounds, and finally a damaged ignition starter solenoid. The IGS is not the solenoid attached to the starter.


1

It depends on exactly what type of engine, but typically it will get to around 1000C after only a couple of seconds.


1

It varies with the type, but anywhere between 5A to 15A for 12v systems, so 4 plugs can be 60A which is why the cable used is a heavy gauge . The power is then between 60W to 720W.


1

Your mechanic seems to have repaired the fault by replacing the alternator. A faulty alternator will drain the battery as you describe and can be quite dramatic in causing other symptoms.


1

Be careful if you decide to 'test' your new glow plugs. The lot of glow plugs start off with 12 volts, but then after 2 seconds the voltage is dropped by their ECU to 4 volts operating voltage. If you keep a supply of 12 volts to the glow plug they will burn out and become useless.


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