Diesel

"Dr Wu" wrote

It's a bit complicated but basically it explains a type of engine where the pressurisation of the fuel system and the injection are electronically separated as opposed to being mechanically linked. This makes the engine very efficient and reduces emissions.

The message from "Dr Wu" contains these words:

Old diesels had a pump which shoved a bit of fuel down a pipe for each cylinder as it needed it. The amount and timing was controlled by a mechanical system which actually offered surprisingly little control - the shape of the pulse of fuel, for example wasn't variable, it was fixed by the shape of the cam which drove the pump barrel.

Common rail has no individual pump but instead has a single extremely high pressure fuel line running to electronically controlled injectors, one for each cylinder. Under control from the computer these tap fuel from the supply and can modulate the rate of delivery very much more cleverly than before. This makes them more efficient and allows other tricks to increase smoothness etc.

You could have a look at the Wikipedia...

What model Rover, just out of interest?

My bet is a 75. The CR engines are all from BMW.

Huw

Doesn't the insanely high injection pressure mean that direct injection works a lot better too, which is more efficient than indirect?

cheers, clive

The message from "Clive George" contains these words:

That too.

Dr Wu ( snipped-for-privacy@tiscali.co.uk) gurgled happily, sounding much like they were saying :

Don't think that's common rail.

I didn't think they fitted the BMW engine in those. Did they? If not then it is not fitted with common rail injection although it certainly will be direct injection and a good enough engine even if less refined than the CR units.

Huw

The message from "Dr Wu" contains these words:

That's nothing, even my Montego engine did more than that. My Audi's done 1/4 million miles and still runs beautifully and doesn't use any oil.

That's my ultimate point but I was waiting and seeing for the time being.

Longevity not make one great, and at 150,000 miles, it's barely run in!

I know I've posted this link before Guy, but even a 16 year-old Astra with the 'old' GM 1.7 diesel engine, appears to still be running quite smoothly after half a million miles with regular basic servicing.

I know of one recently sold with a quarter million and still running like a watch.

Huw

It could also be near shagged.

Huw

My 15 year-old Astra 1.7D runs brilliantly, it has 140,000 miles on the clock, and is very economical to run and maintain, although nuff said about the (still) weeping fuel pump!

The message from "Ivan" contains these words:

I reckon a good part of it is mechanical sympathy along with regular oil changes.

Along with regular physical inspections and a dollop of luck.

Huw