A little help please, misfires.

[SarTech]

Hello all.
I have a 2002, X5, 3.0l, manual trans,165K miles. I purchased the car used with about 120K on it, Im the second owner.
Last month I had the thermostat go bad, engine would never warm up.
I replace thermostat, water pump and fan clutch.

Shortly after I got a Service Engine Soon (SES) light with codes, P1351, P0304, P0302, P0306, P0303 and P0301, all misfire codes.

I thought that I might have gotten some bad gas. Put in some Sea Foam cleaner, reset codes , all was well for a a couple trips in to town (about 40 miles round trip)
I got the SES again and basically the same codes.

Checked the spark plugs, found that they were very worn. Replace, reset codes.
Again, all was good for a trip or two into town.
Then SES, with P1342 and P1351 codes (Misfire during start and misfire cyl #5 with fuel cut-off)

Swopped #5 coil and #3 coil, reset codes.
Drove into town, on the way home SES with 1351 and 1345 codes. (misfire cyl #2 and #5 w/ fuel cut-off)
Since I had the parts any way I replace the Crank Case Vent valve and hoses.

On the way in to town SES with 1351 code. Reset codes, On another day went into town, on the way back home SES with 1351, 1349, 1345 and P0300 codes.
Replaced all coils, reset codes.

Drove into town, cars running very well, thinking I got this fixed. On the way back home bam! SES!!! with 1351, 1349, 1345 P0300.

What now? any suggestions?
The fuel pump and fuel filter has been replace about 40K miles ago.
Sure would appreciate any help.
Thanks.

[BMWX5CHI]

For your codes all of those could be cause by a number of things. Vacuum leak CCV or Faulty ignition coil (s). First check your intake boot. It might be cracked and could be causing a vacuum leak. Also make sure you all of the CCV hoses are on correctly. Check those things first.

[SarTech]

Originally Posted by BMWX5CHI

For your codes all of those could be cause by a number of things. Vacuum leak CCV or Faulty ignition coil (s). First check your intake boot. It might be cracked and could be causing a vacuum leak. Also make sure you all of the CCV hoses are on correctly. Check those things first.

Boot is good, I did check that. All ignition coils are new. Ill check the CCV hoses again.
Thanks.
PB

[BMWX5CHI]

Check around your intake system for any leaks. Spray brake cleaner or something similar around your intake. If there is a leak you should be able to hear a change in the engine idle. If that checks out check your fuel pressure. Sometime it could also be your MAF sensor. Try cleaning that out with MAF sensor cleaner.

[Joshdub]

It's likely a vac leak. Could be coming from the CCV where you cannot easily see it.

[itscoo2pyopants]

I have some coil packs with 84k miles on them that you can use to help trouble shoot. I am also located in WA

[itscoo2pyopants]

I also have INPA and DIS programs that you can use to help diagnose the problems your having. PM me if your interested

[SarTech]

itscoo2pyopants (not sure about that handle!!) thanks for the help. I have replace the coil packs if I still have problems I might hit you up for the diagnostic help.

This is what I did today on the X5;
-Cleaned the MAF sensor with MAF cleaner.

-Replaced all the little vacuum hoses I could find. Some look pretty bad. Remind me to not do that again. Found a 8mm vacuum plug under the intake manifold cracked and poorly fitting. Replace that plug.

-Checked the fuel pressure. Followed the procedures in my Bentley service manual. Had zero pressure when I connected the gauge. The book said I should have 50 psi+/- 3 psi engine not running residual pressure. With the fuel pump jumped and engine not running I should have 50 psi, that was correct. With engine running I should have 36-47 psi that was good. Once engine turned off the psi slowly, slowly creeps down. I suspect the pressure regulator is bad.

Ill order a new fuel filter and pressure regulator.
Ill keep you posted on how things go.
PB

[BMWX5CHI]

Looks like that might be promising. Also could be fouled/clogged injectors. Lets hope you are able to fix it. Good luck.

[SarTech]

Well, replaced the fuel filter and no joy. Still getting the misfire codes.
I have:
replaced the spark plugs
replaced all coil packs
replaced the CCV system
cleaned the MAF
cleaned the DISA valve
replaced all vacuum lines that I can find
replaced fuel filter.

Also, after the car sits overnight the static fuel pressure bleeds off. Car starts fine, thinking the bleed off is due to the gas cap. What do you think about that?

Any other suggestion for solving this very random misfire events.