BimmerFest BMW Forum banner

2007 X5 4.8i Erratic idle, no power, 2A84 , 2A91 Any Help?

8310 Views 26 Replies 4 Participants Last post by  Marcelo Godoy
Hello Guys,

I am struggling with a 2007 X5 4.8i v8

I started this journey replacing the PCV, it ran fine for about a month, then it start having an erratic idle, no power, misfiring, it got to the point where the engine knocked for a few seconds then went back to normal. Like the timing was adjusting or something.

The current codes are 2A84 and 2A91.

I cleaned and swap the Vanos solenoids bank 2, it didn't help

Swap Camshaft sensor to a different bank, still the same. ( I didn't touch the exhaust cps because it was out of my range) I re-checked the connections tho, cleaned them up real good : nothing has changed.

One coil is bad, it was giving me a misfire cylinder 1, I swap to cylinder 2 and the misfire followed it. ( waiting for a new coil to eliminate the misfire ) .. codes added to the list 29CC,29CD

I really appreciate any help.

+ info : I believe the vehicle had a very old oil, did oil change and old oil was very dirty ****
1 - 20 of 27 Posts
If you have a single bad coil that's all you need for your symptoms.

Get the replacement in, clear the codes, run some injector cleaner through (I usually use Lucas at one bottle per ten gallons).

Report back after. It's pointless to try to fix anything when you have a bad coil. The car will kick on limp mode with one bad coil. You did the right test to see if the error will follow a coil swap so now you replace and go from there.
2A84DME: Inlet VANOS 2n62_tue2Engine electronicsView
Fault Information

Fault Code Description
Fault Code Conditions
Fault Time Condition
Inlet VANOS 2
Service Plan

'A' Camshaft Position - Timing Over-Retarded (Bank 2)
Fault Impact
none
KL_15 = true

Bank 2 intake controller monitor
(max. control deviation (differential spec./actual data) is 5°KW)
VANOS may not be at travel limit, that is Vsa2_sprs<120°KW.
Warnings
Service Notes
Test sequence (after each step stop to determine whether fault is present):
1. If the corresponding camshaft fault has been logged, start by checking the camshaft sensor
2. Check oil level
3. Check VANOS valve for contamination
4. Replace solenoid valve
5. Replace VANOS adjustment mechanism
© 2021 - BMWFaultCodes
2A91DME: Exhaust camshaft 2, tooth offset to crankshaftn62_tue2Engine electronicsView

Fault Information

Fault Code Description
Fault Code Conditions
Fault Time Condition
Exhaust camshaft 2, tooth offset to crankshaft
Service Plan

Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor B)
Fault Impact
none
KL_15 = true

One-Tooth-Off detection on bank 2 exhaust
(if OK: Vsa2_adp delta for last driving cycle < 16°KW (Dnwoto_mn/mn))
VANOS must be against travel stop, thus Vsa2_sprs=120°KW.
Warnings
Service Notes
Test sequence (after each step stop to determine whether fault is present):
1. If entry for corresponding camshaft sensor is present, start by checking camshaft sensor
2. Check solenoid valve for contamination / inspect terminals
3. Cross-change solenoid valves
4. Check/correct camshaft and valve timing and/or alignment
5. Replace VANOS servo unit
6. Install new timing chain assembly (complete)
© 2021 - BMWFaultCodes
The big clue.
I believe the vehicle had a very old oil, did oil change and old oil was very dirty ****
Thanks for the answer .. Yeah the coil arrived and it fixed the misfire . now, Code 2A8D and 2A91(P0019 / P0024) is still present. What's next?
If you have a single bad coil that's all you need for your symptoms.

Get the replacement in, clear the codes, run some injector cleaner through (I usually use Lucas at one bottle per ten gallons).

Report back after. It's pointless to try to fix anything when you have a bad coil. The car will kick on limp mode with one bad coil. You did the right test to see if the error will follow a coil swap so now you replace and go from there.
Cam and crank sensor errors.

It's pretty rare to actually get an error directly related but I would start with the crank sensor. Did you state how many miles?
The over/advance cam error can be an error carried forward from from crank sensor
Vehicle has 128850 miles.

Do you mean the black sensors by the firewall panel right? I got the top one out, swap w the left bank 1 side, but I am struggling to get the exhaust sensor out. any tip on how to get it out?

I ordered 2 vanos valve and 2 cam sensors, arriving tomorrow : /
The over/advance cam error can be an error carried forward from from crank sensor
Crank sensor should be under the motor. I've never changed one on n62 not sure where it is.
It sits on the bell housing, sensing the flywheel teeth, bottom/right hand side.




Verzonden vanaf mijn iPhone met Tapatalk
BMW E70 X5 4.8i SAV / Wiring Diagrams and Functional Description / Power train / Engine electronics ME9 /
11 03 05 (142)
8-cylinder spark-ignition engine N62TU

Crankshaft sensor

The crankshaft sensor records the position of the crankshaft with the aid of an increment gear screwed to the crankshaft. The crankshaft sensor is required in order to achieve fully sequential fuel injection (individual fuel injection for each cylinder at optimum firing point). The crankshaft sensor works according to the Hall effect.

The circumference of the increment gear is divided into 60 equal teeth. The crankshaft sensor generates signal pulses. These signal pulses become shorter as the engine speed increases. The precise position of the pistons must be known for the fuel injection and the ignition to be synchronised. The increment gear has a gap of 2 teeth for this purpose.

The number of teeth between the two gaps is permanently monitored. The signals from the camshaft sensors are compared to that from the crankshaft sensor. The signals must be within specified limits.

If the crankshaft sensor fails, a substitute value is generated from the camshaft sensor signal (for engine starting and running).

The integrated supply module supplies voltage to the crankshaft sensor.
That last statement is quite important. When that power supply goes wonky it can kill your feed to the crank sensor.
Thank you all ..

So, you all agree it not the Vanos solenoid nor the camshaft sensor? Should I just replace the crankshaft sensor instead?
I ordered the crankshaft sensor, I will update you guys next week.

The vehicle now is driving much better, got the power back but not sure if to its fullest. I am still getting p0019 p0024 ( 2A8D and 2A91) .. you guys are probably right about the crankshaft so I will wait for the part to arrive.

Thank you so much and have a great weekend
Odds very good on cam sensor also but I would replace crank first.

Also: vanos is sensitive to oil viscosity/clean and oil filter. Old oil wrong weight can cause problems
  • Like
Reactions: Marcelo Godoy
Nr 8 here



Verzonden vanaf mijn iPhone met Tapatalk
  • Like
Reactions: Marcelo Godoy
hello guys,
Crankshaft replaced underneath the engine.... errors still shown . 2A8D , 2A91
1038196



Replaced 2 vanos solenoids bank 2, still same error.. where do I go next?
1038195


Car is driving better, doesnt have the full power tho.
Ok another update..

I found online the Vanos solenoid harness diagram and realized their connectors were swapped from each other(done by the previous owner) . I re connected them correctly and now the 2A8D code is gone, the adaptation now are reading the same for both banks (+-77), not sure if that's the correct value for both of them ..

The 2A91 is still present. Crankshaft sensor was removed, now I am going to replace the Camshaft Exhaust sensor( once the inlet was already replaced)

I'll keep you guys posted ..
With foxwell you can graph request and actual cam angle on the same chart. Do that and see how they compare. That's how determine State of the CPS since they rarely ever show as direct error
1 - 20 of 27 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top