Help, my 525 is guzzling petrol like its water!

[bimmerlicious]

Hi all. Got my car a few months ago. Everything was OK until sent it for service recently. Car info E39 525 year 2000 UK spec. Normally when I fill up the tank, the indicator will show something like 380/90 miles, and i will get an average 360/70 miles in actual with my driving style. After I sent it to service, I'm getting on 260/70 miles before hv to refill again. SHort about 100 miles or 160 kms.. aiyoooo... Still, computer will estimate 380/90 miles. Refilled at different shell stations, same result. Engine sounding somewhat louder than before, especially if car is left idling for sometime (say 10-15 minutes while I leave the kids and wife in the car when running errands). Previously hardly any loud engine noise if i accelerate to 100-120 kmh. Do not notice any irregularities with RPM (probably too daft to notice anyway... heheh) only gets louder a tad hitting 140-160, still not as loud as it is now.Took the car to m-performance, did diagnostics, everything showed OK. Pomen said could be "air valve" not working, but have not had that checked yet b'c Raya and cannot leave the car in the shop. When I took the car to service, my mechanic did the setting at beemerholics in subang jaya. Just refilled again tonight... now computer is estimating I should be able to drive 515 miles!!!!! NUTSS!!! Now here are my questions to the more knowledgeable folks out there:1. Can the computer/software they use differentiate between UK, Japan or other specs? I think it does matter because for service intervals 10000km and 10000miles is very different!!2.is it possible that one shop might have an inferior diag software then others i.e. older version etc?3.could it be that because of the error in setting, the engine is running in "performance" mode all the time instead of "economical" (not really sure if this applies to bmws, so my apology for lack of knowledge).4. can the software "miss" diagnose the engine setting? i.e. should indicate problem but does not? what is this world turning into if we can't trust the computer to correctly diagnose the car.. hehehehehI thinking of taking the car to m-speed tomorrow morning to run diagnostics again. hope the guys there will be able to help. Have not been there before, but people in this forum seems to have high remarks for them. wish me luck!

 

[Vincent Hor]

Ah Meng of M-Speed is very good at E46 & E39. He should be able to help you.

 

[Replay]

is your obc readings all in miles? there should be a button to change from M to KM's.... the obc range estimates can be sometimes over optimistic.... whats your range on a full tank of gas?

 

[macgy]

i hv the same car, full tank filled,indicator show around 300 miles. actual mileage ranging fr 280 to 310 miles.

 

[bimmerlicious]

Ah Meng of M-Speed is very good at E46 & E39. He should be able to help you.

went to see Ah Meng last Saturday - initial impression nice chap and very knowledgeable. Did diagnostics, found 1 fault with transmission, something about clutch locking up. Since my car already racked up 123K km, he said service manual says gear-box should be overhauled - RM7,500. Told him, OOOOKKKKK... maybe if I can get bank loan will do it.... hahah We took the car for a test drive. Final diagnosis:

1. Overhaul gear-box - will not do this now, but will service i.e. tukar minyak and filters - rough estimate - minyak $560 (8 litre x $70), filter set ($200-300)
2. Over 125K, need to check fuel pump and float - will do later perhaps, just gassed up the car, so cannot do it that day.
3. Check exzos, catalytic converter might be clogged up, hence loss of power (takdak back force) and makan minyak lebih... Took the car immediately to an exzos shop in Kelana Jaya... found out that something already broken in muffler - not catalytic but some other internal parts... pomen said ori BMW could set me off $5-6k, so decided to go fo a local universal one (very quick decision... hahah), all in cost me $560. Now the car runs better... :top:
4.Slight vibration - need to change engine front mounting - estimate $400ish... will do later.

 

[bimmerlicious]

is your obc readings all in miles? there should be a button to change from M to KM's.... the obc range estimates can be sometimes over optimistic.... whats your range on a full tank of gas?

Readings are in miles. Hv not found button to change setting to KM from miles. Only can re-set trip meter, average speed and average MPG. That said, hv now changed to KM, did this via the computer after running diagnostics. full tank previously can run up to 360-70 miles, with OBC estimate 398. Think ada problem with this, see my other reply.:106:

 

[bimmerlicious]

i hv the same car, full tank filled,indicator show around 300 miles. actual mileage ranging fr 280 to 310 miles.

Macgy, think something wrong with my OBC... since i bought the car a few months back, estimates have always been around 398 miles and actuals average 360-370 miles. Sent the car for service a month ago, after coming back, estimate still (until recently) 388-398, actual now average 250-260 miles. Gassed up last week, estimate went to 515 miles!!! crazy huh? anyway, changed the reading to KM... so will monitor the readings again. Thinking Ah Meng could be spot on when he said float needs to be looked at.... :106:

 

[affan66]

the reading will be based on the last trip you made. If you were doing long distance, the next fuel up will indicate a higher full trip estimate. Mine has shown between 450km to 800km. I don't quite bother about this unless it goes below 399km on a full tank.