96 Disco 300tdi reluctant starter in cold weather

As`a general suggestion for any diesel, first try putting some injector cleaner in the fuel, and see if that improves things.

If not, the list starts with one or more sticky/ worn injectors, and on and on.....

The list should start with checking the glow plugs individually unless there's money burning its way out of your pocket to replace them all at the same time. It's quick, easy and inexpensive.

I had that trouble last winter and a quick change of the glows sorted it out, not too much either.

I had problems with my TDI 300 in the recent cold spell

Complete replacement of all the glow plugs sorted things

Cheap on the net but it cost me 50 odd quid

DieSea

i was having trouble starting mine until i realised that it starts much better from very cold if you dont touch the trottle at all

Chris..

On or around Sat, 17 Jan 2009 03:47:25 -0800 (PST), Tony enlightened us thusly:

yep. glow plugs.

A good TDi doesn't need them when it's not cold, if it has a good and big battery.

but once it's below freezing...

pul the plugs, check them by connecting across the battery using a fat wire such as a jump lead - hold 'em with pliers cos they get hot.

Any that don't glow at the tip after a few seconds are dud. I've once seen one that glowed half-way up.

And if any are dead, replace the lot as those that still work will have been damaged by the greater voltage that reaches them when not all glow plugs are functioning.

On or around Sun, 18 Jan 2009 16:57:29 +1300, EMB enlightened us thusly:

they're parallel ones...

but that would be true on a series motor.

Still good policy to replace all of them - they all start off new together and if more than one has failed, they're obviously getting near end-of-life.

However, if you're skint, changing only the dud ones will get it working short-term. Chances are you'll find all or most are dead, from the symptoms...

Exactly my point - when all the glow plugs are functioning there is a significant voltage drop in the wiring to them. When one or more fails the current draw and thus voltage drop is significantly less causing the remaining functioning glow plugs to be running on excess voltage. This significantly reduces their remaining lifespan.

No damage on series glow plugs as once one plug goes open circuit none of them receive any voltage.

Agreed.

On or around Mon, 19 Jan 2009 14:40:00 +1300, EMB enlightened us thusly:

possibly, I doubt it's been measured. The wiring and such tends to be pretty fat, and have something like a 70A relay, so I'd not expect enormous voltage differences. I've certainly found motors with one or two duds and the others still working.

yeah, I thought of that after I posted it.