Post by comfortablynumb on Nov 10, 2019 18:49:37 GMT
Evening all Car is actually a p38 rr, but 2.5 diesel Fuel consumption never that good, but is steadily getting worse Fuel computer figures used to hover around the 29mpg mark, but is on a steady downward curve, now registering 27.4, even on a 350 mile trip today, mostly A roads/motorways but all under 3k rpm It has now done 211k, and smokes under load, but ‘they all do that sir’ An I expecting too much, or is the engine dying, or the electronics lying, in a p38? Surely not!😳 Doesn't feel any different to drive, never been exactly land speed material anyway Any ideas? TIA
Post by comfortablynumb on Nov 11, 2019 6:29:12 GMT
Its supposed to be a hack until i get the daily rrc back up and running, its always smoked, in fact under severe load the road behind disappears! Think ill try the injector cleaner first because (a) its cheap and (b) I'm basically a lazy sod Thanks for help all
Thats still pretty good consumption from a 2.5d p38...amazed you were getting near 30mpg. here is my hit list in order of things to check with the m51 bmw engine
1. Fuel filters- if blocked it will make the performance poor and smoke under load 2. Intercooler Hoses- If split or collapsing under load will make noteable smoke and not perform as well 3. EGR system...clean EGR valve or blank off alltogether 4. Injectors..leak off tests 5. Turbo-piece of cake to change on these engines 6. Run a 60/40 mix of veg of diesel/vegoil through it...cleaned my m51 lump right out and it ran sweet as a nut and much smoother..be aware you will probably need to change filters after a few hundered miles if the fuel system is full of crap.
m51 is a really simple engine and a doddle to work on
As well as all the above, it may be something as simple as the brakes dragging or the tyre pressures being a bit low. Checking for overly warm wheels after a run or rusty areas on the discs offer clues without stripping the vehicle. Good luck