BMW M5 Forum and M6 Forums banner

1 - 13 of 13 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter #1
aaaah any help

so night before vehicle ran totally fine, started in the morning felt like misfire.left the vehicle and switch cars. started later and ran like
misfire. hook up bavarian code reader. cylinder #4 coil. easy right replaced and still runs like crap. ran code lambda 1/test drove feel lack of
power and really rough idle/check and cleaned plugs and coils an right side. cleared code now lambda #2 and o2 sensor code. drove to friend and he retrieved 02 codes. replaced 02 on drivers side and still on limp mode.all of drivers side coils not working,
anyone have experinced this, help would be appreciated, thanks mike
 

·
Registered
Joined
·
3,725 Posts
Try the crank sensor and check your battery voltage - I just went through a week of this with my E34 530i (M60B30)

Crank sensor should read 540 ohms exactly , I can't remember if its the left 2 or right 2 pins (there are 3 pins)

Even if the crank sensor is showing up ok on the multi meter it could still be intermitent.

You'll have to remove the engine cover (4 x 10mm) bolts.

Are you able to rev past 3,500rpm ?
 

·
Registered
Joined
·
30 Posts
Discussion Starter #3
heeeeelp limp mode

he thanks,

my friend checked the cranks sensor and says it is good, anybody else had this issue and it is not resolved?

mike:crying2: 540i
 

·
Registered
Joined
·
3,725 Posts
Crank sensor should be 540 ohm but I had a new one put in by the dealer last week and it's reading 614 ohm (?)

Prior to that I had a wrong pn and had an M20 crank sensor on the engine at 720 ohm and it played hell with the DME , the engine would run for 5 mins then shut down.
 

·
Registered
Joined
·
3,725 Posts
Check you have power and signal to the coils.

The 2 outer terminals of the harness for each coil pack is the power supply. I checked mine last night and the coils were getting 13.7 volts.

The centre terminal is the signal from the DME to the coil.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #7
haaaaaa limp mode

well we measured it and it was under spec, so we put another crank sensor and still in limp mode
we checked the fuel pressure and it is at 55 psi it has a code of 203 o2 sensor control 2.
check for vacuum leak looks good


any help out there, it is cold world in the limp mode world

thanks in advance
mike
 

·
Registered
Joined
·
3,725 Posts
Tried a DME reset already I suppose ?

I found the best way to really reset the DME was to take it out of the car and leave it on the bench for 30 mins
 

·
Registered
Joined
·
3,725 Posts
The M60 is super sensitive on coils.

Check the resistance of all the coil packs , I put 4 new coils in a few weeks ago and one of the new coil packs had failed.

I was getting coil pack resistances on average of 1 ohm (range 0.9 to 1.1) , the failed coil was 475 ohms
 

·
Registered
Joined
·
3,725 Posts
For a start I'd multimeter every sensor you can get access to.

Do you have ASC on the car ? Sometimes the throttle cable snaps on the second MAF causes the the car to lose power.

How do you know the car is in limp mode ? Is it just down on power or do you have an rpm limit (3,500) ?
 

·
Registered
Joined
·
3,725 Posts
Posted 18 February 2013 - 12:21 AM
I had major hassle finding a chronic misfire on my 540 which could occur at any time but would always start with a gradual stutter & loss of power before developing into seriously bad running & terrible fuel consumption. As above the only faults flagged were for the lambdas & changing both for new OEM ones made no difference.

It took a over a year to solve but the problem turned out to the DME itself. Purely on a whim I decided to get a replacement from a scrapper & the issue was cured immediately & has never returned.

E34 540 runs ruff. - E34 1988-1996 - BMW 5 Series Owners Board
I found this , sound familiar ?
 

·
Registered
Joined
·
30 Posts
Discussion Starter #13
limp mode is killing me

well fuel pressure at 55psi/new crank sensor due to now quite within specs,
new #3 coil/new o2 sensor/did not see any vacuum leaks, performed smog test and it is good, disconnected the battery,recharged the battery/no luck a few times the car ran good for 10 seconds or less,

anything missing here? the left side bank is not working/swapped coils from the other side/check the connections on that side.
refilled the fuel tank just in case due to it was slightly low on gas,

very frustrated,

if it is a bad dme would it have ran good twice for a few seconds.twice?
 
1 - 13 of 13 Posts
Top