Thread: Disco 3 2.7TD Piston Meltdown

Jesus, who charged you $14K for a second hand engine, there is a Brand new twin turbo V8 LR motor on ebay at the moment for $12K. I would be having the injectors tested at a recognised Injection service centre, why didn't you use the injectors from the secondhand engine, as a melted piston in a diesel is usually caused by overfuelling, I would be very wary of at least that injector, Regards Frank.

This is a diesel, right ?

If so, too much boost or a lean condition won't melt a piston fella's, only over fuelling or incorrect timing

It's telling that it happened right when overtaking.

I'm guessing something in the ECU, (maybe a MAF ?) has 'told' the injectors to dump more fuel than is safe into the engine or it's chronically advanced the timing, creating excessive combustion temps and pressures.

The only other thing I can think of is a crook/blocked/broken piston oil jet ?

Too much air will cool pistons and turbo's in a diesel, too much fuel, or fuel at the wrong time will kill them.

I'd say the leaking intercooler hose.
When a modern high pressure injection diesel starts blowing black smoke, your EGT's are already way beyond dangerous. That could have melted/cracked the piston the first time, the passing was enough to finish it off.

Because the leak was downstream of the airflow sensors, the computer was counting all this air that wasn't making it to the cylinders, thus overfuelling, dangerous EGT's and black smoke until the leak was fixed.

Yeah but the manifold pressure would be down.

I think it is isolated to that one injector ATM. If timing or any other problem wouldn't it affect more chambers.

Originally Posted by lambrover

Yeah but the manifold pressure would be down.

Where are the MAP sensors on those engines? Yes they should register a drop in pressure and cut back on fuel, but the black smoke suggests not enough.

Hi All, Thanks for your replies to this perplexing issue. We have a diesel specialist in my town which I will contact and see whats what with any injectors...I would like to test them for certain. They have been flow tested and that shows no restrictions but as for pattern etc...who knows? rick130..the blocked cylinder oil line....that is a chance...potentially the black smoke could contaminate the oil too I would suspect....
The long engine cost $6,818 the turbo replacement all up cost $1,800...the rest was labor on the engine and I had some other work like a transmission oil replacement and brakes etc.....wouldn't mind that V8 though!! Thanks all JD

Reckon rick130 is right , Piston cooling spray/nozzle blocked with a tiny bit of silasticky type crap . Oil rifles not cleaned out properly