Poor MPG: Check/replace Camshaft Position Sensors
 

Hi,
My '01 X5 3.0i 5Spd, ~85,000 miles, mileage began to drop noticeably (from 19.6 to 16) last year. About 6 months later it started throwing fault codes for the camshaft position sensors- first one and then a few weeks later the other one. After replacing them, my car runs MUCH! better and the mileage is back up to normal.
My understanding is that as these fail they cause the car to run rich.

Replacing both sensors is easy- one is easier than changing an air filter as you literally disconnect a harness, unscrew one screw, pull out the sensor and reverse the process. No need to remove anything to get at it. The other involves a bit more work but is easily accomplished in an hour or less I certainly would not pay the dealer $200 in labor for this job, even if you have no mechanical skills. There are instructions somewhere on one of these forums...

Best of Luck,
Randy Hermann

Hi,
How can you check the sensors to see if they are good? Secondly, I see there are 2 types of sensors, one with harness and another one without for 2001 3.oL. What type did you fit on your 01?

ok, I found this
http://www.xoutpost.com/articles/x5/e...placement.html

Two sensors on the car- one has a harness (the one on the drivers side). The one on the passengers side does not have the harness.

If/when they trigger the Service Engine Soon light, the OBD code will indicate which has failed.

Got to run...

Let me know if you have any trouble with the install...

-Randy

That is terrible! My X always got about 15-16 in the city

I need to clarify the "harness/no harness" comment. I don't remember exactly what the difference was between the two. They were definitely different pieces, and the one on the passenger (USA) side was smaller in total size- it seems like the drivers side one had a short wiring harness as part of the piece but I could be mistaken on that. Sorry for any confusion.

Also, there is another write-up on how to replace the things, maybe in one of the other bimmer forums.

Be careful so that you don't drop the screw on the drivers side piece!

Good Luck- it is relatively easy to replace these buggers.

Randy

I've gotten an extra 2-3mpg from just changing spark plugs. The X had Bosch +4 Platinums (crappy plugs, would never use them again) and I changed them out for the OEM NGK plug (NGK Part Number:BKR6EQUP, BMW Part Number 12 12 9 071 003). Don't get them at a dealership though, its about $25 a plug for them. Bimmerspecialist.ca / .com has them for $13.

Just to throw another vendor out there, www.sparkplugs.com has them for $8.48 each. You might also want to check with Napa. They sell spark plugs for really low prices, and you won't have to pay shipping.

Very true about sparkplugs.com, but by the time I pay Duty, and brokerage shipping it over the border, I may as well have bought them over at my dealership. Napa sells them up here for 16$ a plug, and since bimmerspecialist.ca ships ground out of Toronto, it only costs me $10 bux total shipping for each package, and I usually order 5 or 6 items at a time.