Testing glowplugs

Nov 22, 2006 42 Replies

Well, based on what I've seen with a single failed glowplug before, it takes a few seconds for the car to go from running rough to what I would consider normal running (for when it had only just been started). I figure that what's happened at that point is the diesel has started self-igniting under compression without glowplug assistance. Therefore, I think it's a few seconds.

Sorry, I thought that was obvious from my original answer.

a few seconds, up to about twenty, depending on temperature and engine condition

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "ThePunisher" saying something like:

Depends on the engine, air temp, quality of fuel, turboed or not, etc, etc.

I've seen glowplug-less bus engines take a lot of cranking on cold mornings but they do start, albeit smokily.

The message from "ThePunisher" contains these words:

Depends. Some engines don't have glowplugs. Transits of a certain age didn't - though there were times when they were complete bastards to start because of minor degradations of age which wouldn't have been a problem if either a) serviced properly or b) fitted with glowplugs.

Exactly, which means the OPs rough running engine has nothing to do with glowplugs.

Can you explain your deduction?

"ThePunisher" wrote in news:JCjch.1672 $ snipped-for-privacy@newsfe2-gui.ntli.net:

Eh? Of course it has. It's only rough when very cold on start up and runs sweet after a few seconds. When the outside temp is warmer, no problem. It's obviously the glow plugs, or one of them anyway, as it sounds like its running on three then the last one kicks in.

The message from Tunku contains these words:

I've lost track of this thread, but if that's what the OP's symptoms are then it's exactly the same as the symptoms I've had every time I've had a plug fail.

Well, that's not what you said before,

"Engine starts ok, feels like it's missing on one before it warms. Nice plume of smoke on cold mornings :-)"

Seems your defination of a warm engine is one thats beem running a few seconds.

Forget about it, the OPs 'warm' engine hadn't even been running for 30 seconds

As I said before, it depends on what's getting warm...whole engine or inside of the cylinders.

"ThePunisher" wrote in news:zzlch.942$3S1.691 @newsfe1-gui.ntli.net:

Warm enough for ignition, which is what this thread is about.

Well, why didn't you say that in the first place?

"Engine starts ok"

"feels like it's missing on one before it warms"

Yes, you can tell from those words of wisdom that what you ment is 'warm enough for ignition'

I think that if you said to most people that the 'engine' is warm they would take it as meaning the temp gauge has started to move, not the insides of the cylinders are warm (which of course only takes a couple of seconds on any engine)

Contxt is everything though.

Depends who the 'you' is. If it's me, obviously yes, if it's you, obviously not. ;-)

Yes, and so is writing in plain English,

"Engine starts ok but runs rough for a few seconds with a large plum of smoke, like it's only running on a couple of cylinders, could this be caused by the glowplugs?"

The message from "ThePunisher" contains these words:

Yes.

Can't we just test them and fix it?

"ThePunisher" wrote in news:5gGch.3118$ snipped-for-privacy@newsfe4-gui.ntli.net:

as opposed to

"Engine starts ok, feels like it's missing on one before it warms. Nice plume of smoke on cold mornings :-)"

Exactly, you'll notice there's no 'before it warms' in my sentence.

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