Car model and year: 2006 BMW E60 M5 with 172k miles
Symptoms:
1. the M5 on a cold start would idle really weird. Would fire up,
fill the cats, and then would boggle up and down 550-900 and fluctuate
nonstop. If you drove the car for 2 minutes, that would stabilize.
2. When I fill up gas and try to start the car, it will start, run for
2-3 seconds, then stall. I start her up again and she fires right up and
starts bogging even on a warm start. Once again, if I drive it for a
few minutes, it stabilizes and all is well. I’m led to believe I have a
fueling issue or perhaps electrical somewhere because even when I close
my gas cap, I get in the car and it will show me that I need to tighten
my gas cap. And always, after I fill up, I start having issues.
3. LASTLY but THE MAJOR ONE. intermittent misfires occasionally
And check engine light is on.
BMW specific scan is needed:
If your check engine light on. Please stop replacing parts without
doing a full BMW specific scan on the car. Don’t assume ignition coils
are bad. If you are a DYI person, get a good scanner and pull the codes.
These cars are smart enough to diagnose themselves, well, for the most
part.
What BMW E60 M5 scan tool is verified working?
Option 1. Foxwell NT530 scanner
My favorite is Foxwell NT530, costs $169 at Obd2tool.com, and look at the codes.
Please scan the car and report the errors you see. A generic OBD2 scanner will not help.
Some of the codes will be misleading: Eg: it may show you misfire in
cylinders, and also show throttle actuator error. So, you have to fix
the throttle actuaror.
Misfire happens due to bad throttle actuators, putting your car into limp mode.
For the record, this car will not be nice to you if you are being
super nice to it by doing oil changes, giving it a nice car wash,
getting it fully detailed, waxing the paint etc.
The car has huge electrical/plastic/electronic issues everywhere. It
can bankrupt you in maintenance charges if you are not doing all this
yourself. Lot of valves, actuators, seals, will fail and they need
replacement. It can get pretty hefty if you go to a service shop.
Option 2. BMW ISTA software
If you have “gas cap” fault means the tank is not breathing in
properly, either the gas cap is leaking but most likely the charcoal
canister, DMTL pump or tank valves are inoperative.
There is a specific fault codes for the DMTL pump, valve, and the
DMTL heating system but you have not got any of them. That being said, I
am not sure how accurate the car diagnosis system regarding this
system, a possibility is the system is electrically connected but
doesn’t function as supposed to. The charcoal canister doesn’t have a
specific code but I think it is included under “gas cap” fault
troubleshooting sequence.
The DMTL system can be tested with ISTA to verify the system
integrity. The “gas cap” fault should be inserted in ISTA test plan and
work through the suggested steps by ISTA, or experienced tech should
access the Function Structure and perform the related tests such as the
DMTL system and tank vent valves, and to have a look at the fuel
pressure and test the fuel pump and or if fuel filter is clogged.
Here is a list of the codes:
Multiple errors may show up, but catch the first one upstream in the flow.
If it shows TA error and O2 post cat sensor, fix the TA first.
With the V10,V8s and V12s, without expensive investment into new
parts randomly, you can switch some parts to the other bank to rule them
out.
If you have ISTA
, run fuel pump pressure test , I had the sort of issues you are
experiencing and this test showed I had fuel pressure issues , I changed
fuel pump and filter and all good after . If you’ve never had pump or
filter at your miles I would change them anyway.
I also changed fuel pressure sensor , fuel tank vent valves and charcoal
canister as I wanted to cover everything on the fuel pressure side of
things .
Option 3. Autel MaxiPro MP808K
Fuel Injectors shouldn’t be over looked here, especially on higher
mileage cars.. My late 05 BMW E60 model developed a misfire on cyl no
8..on the very first run after I replaced starter motor..(which is a
total pain btw) I swapped coil packs, plugs and ionic modules… still cyl
no 8 misfire.
The scanner I used is an Autel MP808K.. it said “Misfire cyl no 8
with cut off as it was affecting emissions” Its running sweet now that I
changed the “dodgy” injector. Incidentally I had to change the fuel
rails as well, because when I disconnected the fuel line I found out
that something had been chaffing away at the hose and was almost through
to the inner lining of the hose..(see pic).. So I caught this in the
nick of time.. To change the rail, the centre engine harness has to be
disconnected at the ECU box and the whole lot lifted up and swung to the
left for clearance…after that the rails come off with injectors pretty
easily.. just a case of keeping everything clean after that..
Hope it helps!
