To Misfire or not?

[270_BMW]

I have a 2002 X5 3.0i with 251k miles and it’s came with it’s fair share of problems but has been fixable thus far. After running for about 30 minutes and letting it sit for just as long... when firing it back up I am getting a misfire code in cylinders 1 2 and 3.

Which you can tell when it happens as the car begins to chug and run rough.

Though after clearing the codes with it running after a minute or two it clears up and runs fine.

Doesn’t happen all the time but enough to be irritating, especially when it dies in an intersection with a car full of kiddos in rush hour.

Mainly happens when it’s 85+ outside. Noticeable when the engine is warm and then is off for a bit and then you get it fired back up. Haven’t had it happen when the engine is cold. Also never happened during the winter when it dips below 0.


Recently cleaned the MAF, throttle body, idle air control.
Hissing sound coming from around the DISA... which I noticed after I took it off to clean everything else. Probably needs a new o-ring. This issue happened before though.

Replaced OFH Gasket and alternator about 2000 miles ago. Had a bad oil leak.
No hissing with the oil cap off so CCV system seems alright.
Just put a new set of iridium NGK plugs in without any anti-seize since it’s an aluminum block.

Any thoughts?

[80stech]

Definitely replace that DISA o-ring first.

[andrewwynn]

Disa leak should be lean code not misfire. Something you said exactly happened to me (kill in intersection).

Does the car kill periodically on off throttle when going slowly: eg come to a parking spot, release throttle and engine just shuts off (same when pulling into intersection, coast to wait for incoming car then stall)?

I would suspect cam position sensor of that's the case.


Sent from my iPhone using Tapatalk Pro

[270_BMW]

Originally Posted by andrewwynn

Disa leak should be lean code not misfire. Something you said exactly happened to me (kill in intersection).

Does the car kill periodically on off throttle when going slowly: eg come to a parking spot, release throttle and engine just shuts off (same when pulling into intersection, coast to wait for incoming car then stall)?

I would suspect cam position sensor of that's the case.


Sent from my iPhone using Tapatalk Pro

Ah okay. I mean either way I gotta replace it. Lol.

I was looking at that... ther is a guy on YouTube called the 50sKid and he shows a full tear down of the M54 and M52TUB.. just various BMW videos. And he does cover replacement of the camshaft positioning sensor and how it works etc... I do intent to swap out the sensor... but I also wonder what kind of condition all that is in after so many miles.

[270_BMW]

Originally Posted by 80stech

Definitely replace that DISA o-ring first.

It’s in the mail as of this morning. Fingers crossed that helps some.

[andrewwynn]

CPS should last about 130,000.

When I rebuilt my disa I noticed the o-ring was sick and didn't want to leave car disabled while I ordered a new one so I used Teflon tape. I have a special kind that changes color from light to dark blue upon compression so I did some test fittings to determine how many layers I needed to put life into the old o-ring.

[270_BMW]

Originally Posted by andrewwynn

CPS should last about 130,000.

When I rebuilt my disa I noticed the o-ring was sick and didn't want to leave car disabled while I ordered a new one so I used Teflon tape. I have a special kind that changes color from light to dark blue upon compression so I did some test fittings to determine how many layers I needed to put life into the old o-ring.

Would you recommend replacing the Intake and Exhaust CP Sensors?

https://www.bavauto.com/bmw-camshaft...-12147518628k/

https://www.bavauto.com/bmw-camshaft-sensor-12147539165

When you put the new oring in, did you apply any silicon to ease it in to its slot?

[andrewwynn]

I only replaced intake CPS butt in both our X5. Both about 130,000mi. I didn't replace my disa O-ring I. Just added Teflon tape


Sent from my iPhone using Tapatalk Pro

[270_BMW]

Got the CSP Sensor in the mail... now the waiting game...

[oldskewel]

Have you been needing to add coolant?

BTW, I watched all those youtube 50sKid videos - great stuff.