I bought an X3

[Herbmiester 923]

I bought a 2.5l M54 X3 for my daughters. Yes I have twins. They just got their learners and they have already done about 500km in the X3. I didn't pay too much for it and it had a fresh warrant and its got a nice spec, no sunroof, m-sport and most importantly heated seats.. I had the trans serviced, as it was holding gears and was slow to change up. The service helped, and it changes up earlier. What I have found is that it gets really poor fuel economy. Around 13.5 to 14l/100kms. This is not what I expected. I was thinking of getting the injectors cleaned, replacing the o2 sensors, cleaning the MAF sensor and throttle body, new plugs, new fuel and air filter , as well as an oil change. 

I have driven it by myself, just a normal combo of motorway and urban running. The economy doesn't change much between myself and the girls. 

Am I chasing my tail here, are they really that thirsty?

[Eagle 1662]

I borrowed @hqstu X3 3.0 for a short period and OBC was around 12 iirc for my mixed driving, the open road was much better around 10L. 4WD system, auto, heavy\tall and short diff ratio makes them guzzle compared to a say a 330 manual.

Doing the work you above can't hurt and is good maintenance anyway and probably see some increase but i dont you are far off if any. Id say check the fuel trims too to make sure you havent got any vacuum leaks etc. I always higher tyre pressure than BMW's specs which helps.

[Herbmiester 923]

My 3.5l Toyota Highlander got better economy that this X3, and she was a big old thing.

 

[Driftit 2078]

That's some high numbers. My supercharged V8 is 11.8l/100kms on average. 

A friend did have some pretty severe drive train issues in his N52 powered one. Rear Diff chewed itself out. The transfer case bound up. And he had to replace the torque converter which was possibly due to the other two problems. Suspect was incorrect oils when serviced by car yard. Never proven. Dollar reserved it. 

[Vass 831]

Looks great in white and Msport that. I'm contemplating getting one for the wife to replace her 3.0L Outback. That also gets around 13L/100 of mostly city driving so not expecting much of an upgrade in terms of fuel economy. Thinking more in terms of ease of maintenance of having several M54's in the family. Heated seats are an absolute must too.

I'm sure the maintenance items you've outlined will help to a degree. Also remove and clean out the ICV whilst dealing with the throttle body. Worn VANOS seals can also affect low down torque and fuel economy but that's a bit more involved.

You'll probably recoup an extra 1, maaaaaybe 2L/100km doing all that, don't imagine it'll make an earth shattering difference though. I was struggling to stick to 12-13L/100km in my old 325ci with the same engine. The X3 being AWD and significantly bigger & heavier those numbers aren't that surprising I comparison. 

Edited August 2 by Vass

[Allanw 1071]

Vanos seals, plus you'll probably find it's not really getting up to temp properly (remember the gauge is totally useless). Check the REAL coolant temp. They should heat up fairly quick, and stay there. Dunno if the X3's can still access the KTMP vis the dash, but you could do it on E39s' really easy. Otherwise check with a scan tool.

The gauge will show Normal (straight up and down) from about 70C, but it's still not pulled all the cold-start enrichment at that point.

[F10er 65]

DISA flap in the manifold is another one to check. If it's not working the fuel economy will be up. They also have a tendency to fall apart inside the manifold and get sucked into the cylinders, so it's a fairly important thing to check up on.

[Olaf 3317]

Hmmm, yes I think the M54B25 and even B30 e83's are not very light on fuel.  VANOS seals, DISA, vacuum leaks, O2 sensors all conspire to rob M54 of power and thus drink more, so you're returning to familiar territory.

Main rule for any X-drive is to ensure you've the right-sized rated tyres on each corner... incorrect tyres and circumferences that's what leads to the bind-ups/diffs/transfer case issues.  Have a good sniff around under it for leaks, particularly the transfer case.

It should be a decent wagon for your daughters to be driving around in John.  Tyre wear likely to be much higher than an e46 wagon though.

[Herbmiester 923]

On 8/3/2024 at 3:59 PM, Olaf said:

Hmmm, yes I think the M54B25 and even B30 e83's are not very light on fuel.  VANOS seals, DISA, vacuum leaks, O2 sensors all conspire to rob M54 of power and thus drink more, so you're returning to familiar territory.

Main rule for any X-drive is to ensure you've the right-sized rated tyres on each corner... incorrect tyres and circumferences that's what leads to the bind-ups/diffs/transfer case issues.  Have a good sniff around under it for leaks, particularly the transfer case.

It should be a decent wagon for your daughters to be driving around in John.  Tyre wear likely to be much higher than an e46 wagon though.

It does have a square setup, 245/45/19.  I will have a look at the Disa, I rebuilt the one in my beloved old E46. I had a look underneath today and I looks like I have the old oil filter housing leak. I did the Vanos seals on the E46, not sure I am that keen to do those again. 

[Palazzo 477]

A transfer case service is cheap insurance. 

[Olaf 3317]

On 8/4/2024 at 7:48 PM, Palazzo said:

A transfer case service is cheap insurance. 

about to do that on mine!

[Olaf 3317]

On 8/4/2024 at 6:49 PM, Herbmiester said:

It does have a square setup, 245/45/19. 

do check that they're the right circumference for your vehicle!

[Herbmiester 923]

I did a bit of work on the X3, I cleaned the MAF, checked the disa which was sticking, I freed it up and then took the car for a decent drive. The improvement was nearly 1.5l per 100kms around town. Part of the issue was that the trans needed a service and was slow to shift up, and that combined with my daughter erratic driving style contributed to the average economy. I also performed and oil change but I cant see how that would have influenced economy. I also had a faulty coil so I replaced it a good second hand one I had. The car was certainly a bit smoother. Its got to go, My wife has her eye on a e92 Wagon. 

[treone 648]

42 minutes ago, Herbmiester said:

Its got to go

Curious - what would you be looking for it? Not that I really need another car lol

[Herbmiester 923]

5k would do it. What I paid, plus new rear tyres and a trans service at Hutt Automatics. 

[Olaf 3317]

good buying!

[treone 648]

Yeah I reckon that’s good buying for a runaround / daily! Timings not right but who knows haha

[Herbmiester 923]

Not in a big hurry.

 

[Vass 831]

Does it have a tow bar?

[Herbmiester 923]

Unfortunately not.