Planning a "mayor" tune-up

[crystalworks]

^Good list.

The nice thing is that you will have addressed 95% of the common failure points on the M54 (others include cam pos sensors, oil level sensor, etc) and should set yourself quite a nice baseline for maintenance scheduling going forward. Also, all of the above will cost well under $1000.

[andrewwynn]

Be very careful removing disa valve. The pin that holds the flap can fall out into the intake.

Also unless BMW changed the design of the siphon jet pump I'm quite sure they didn't you should address this problem before it strands you and suckers you into replacing a perfectly good fuel pump.



Find my repair on the siphon jet pump DIY.

[titodj]

Originally Posted by andrewwynn

Be very careful removing disa valve. The pin that holds the flap can fall out into the intake.

Also unless BMW changed the design of the siphon jet pump I'm quite sure they didn't you should address this problem before it strands you and suckers you into replacing a perfectly good fuel pump.

Thank you for both tips !!

[Bmwtvboy]

bcbedliner is right. But keep in mind all that tear down and you may rebuild the top end intake. Don't change O2 unless you get code or other issue. Mine went 165K the first time around, second set still on at 241K. WHEN doing the intake manifold removal it's easier to get to all the vacuum lines and be sure to connect the small line going from the CCV to the oil pipe into the pan/block, this helps to improve vacuum pressure. If your doing all this front engine replacement, go ahead and do your Dvanos seals if they haven't been replaced. Good luck , have fun, these are easier and more roomy to work on than the E46 330 Ci.

[titodj]

Originally Posted by Bmwtvboy

Don't change O2 unless you get code or other issue.

If your doing all this front engine replacement, go ahead and do your Dvanos seals if they haven't been replaced.

Thank you... Two questions.
Why should I better wait until I get a code to replace the O2 Sensors?

On average at what mileage the Vanos has to be rebuilt?

Thanks !!

[andrewwynn]

Caveat on wait with O2: if you are getting terrible mpg or have irregular readings change them. $10 app and $20-30 wifi obd2 dongle will get you real time O2 readings.

[Fifty150hs]

Originally Posted by andrewwynn

Caveat on wait with O2: if you are getting terrible mpg or have irregular readings change them. $10 app and $20-30 wifi obd2 dongle will get you real time O2 readings.

What should those 02 readings be? I have 217,000 miles on my sensors and mileage has recently begun to drop.

[bcredliner]

There can be several causes of reduction in mileage not associated with 02 sensors. Pre cat sensors are part of establishing proper air/fuel mixture so can be the culprit if mileage is less but so can other issues such as a vacuum leak, MAF etc. That said, 02 sensors replacement guideline is around 80,000 miles.

[andrewwynn]

My biggest mpg change was plugs. I got 7-10% better mpg when I replaced plugs. Still have suck mpg compared to wife's identical car (I get 20-21 she gets 23-24).

[andrewwynn]

My biggest mpg change was plugs. I got 7-10% better mpg when I replaced plugs. Still have suck mpg compared to wife's identical car (I get 20-21 she gets 23-24).