2009 X5 4.8 - Intermittent loss of power

[getafewlives]

Hi guys,

Recently I have noticed that my X5 will intermittently lose low end power. No warning lights, and nothing that would suggest any sort of issue, other than she runs super sluggish. When it is acting up, there is a super long delay when you press the accelerator, and you really have to floor it to get any real response. Sport mode helps a bit, but it's definitely not the aggressive and responsive beast that she usually is.

Idle seems fine, no issues there.

As far as I can tell, it seems to be random when it happens. But it's definitely a very noticeable difference.

Aside form being super annoying, it is also dangerous not knowing if I will have power when I need it. Sometimes pressing the accelerator down half way barely gets the car moving, other times it will shoot off like a rocket.

Has anyone else experienced this issue? Or have any suggestions on where to start troubleshooting.

All my me ECUs should be updated to the newest version via ISTA/P.

Possibly crankshaft sensor?

Currently at 88,000kms (55,000 miles)

[getafewlives]

No one has any ideas?

Does anyone have a photo of where the crankshaft sensors are on the engine?

[getafewlives]

After more research, I am thinking this could be the VANOS seals. has anyone else had any experience with their VANOS seals failing on their 4.8?

Does anyone have a link to a DIY to replace the VANOS seals?

[Thecastle]

Yes,the Vanos seals fail frequently on these cars.

Could be the following things;
PCV leak
Misfire (check for this)
bad throttle body
bad MAF

Also a lack of fuel, have you had the fuel pump recall done?

[Pierce330]

You just purchased this X correct, if I remember correctly!

[getafewlives]

Originally Posted by Thecastle

Yes,the Vanos seals fail frequently on these cars.

Could be the following things;
PCV leak
Misfire (check for this)
bad throttle body
bad MAF

Also a lack of fuel, have you had the fuel pump recall done?

So yesterday, I replaced the VANOS solenoid seals and cleaned the solenoids with MAF cleaner. The solenoids didn't look too dirty or sludgy.

I also cleaned the MAF sensor while I had everything apart.

Put everything back together,and noticed right away at idle that there was still a delay and hesitation when pressing the accelerator.

Also got a CEL right away. Scaning with INPA revealed 2 engine codes:

- 2A85 Variable camshaft timing (VANOS) exhaust, activation

- 2D13 Air mass sensor, rationality

I cleared the codes, but the 2A85 came back right away this morning.

2D13 did not come back, so I am assuming that was triggered by disconnecting the MAF sensor.

It's interesting that I have a code now for the VANOS solenoid, but didn't before. I would say that the car runs the same as before, with intermittent power in low RPM range. Doesn't seem any better, or any worse.

I am thinking of trying the cleaning method of soaking the solenoids in gasoline for a while, instead of just spraying MAF cleaner on them. I will also swap the intake/exhaust and see if the problem follows.

is there a way to tell from the code which exhaust solenoid (since there's one on each side) is the issue?

I am also going to clean the electrical connections to the solenoids and see if that helps.

I have not done the fuel pump recall yet. I am waiting for the dealer to contact me once the parts for that and the air bag recalls are ready.

[getafewlives]

Originally Posted by Pierce330

You just purchased this X correct, if I remember correctly!

Yes, I purchased it in November, and have put about 7,000kms on it.

[getafewlives]

Here's a photo of one of the solenoids, looks to be in good condition.

[getafewlives]

on Saturday, I had a chance to look into this issue again. Started by taking out the 2 solenoids on the driver's side bank, soaking them in fuel, thoroughly cleaning them, cleaning the connectors, and reinstalling them swapped (intake/exhaust).

No change.

Did the same on the other side, and this seems to have fixed my issue, at least for now. The CEL immediately went away and power has been restored. Engine revs up much quicker and without hesitation, and the power in low RPMs has been greatly improved. I guess time will tell if this is a long term fix.

[getafewlives]

Well, I am still having issues...

I bought a new OEM VANOS solenoid, but swapping it with other VANOS solenoids doesn't seem to make any difference.

When the car is cold, everything seems to run fine. It's only once things have warmed up that I start losing power. From what i am reading, it sounds like it could be the eccentric shaft sensor. Does anyone have any experience with this sensor? Or links to how to get at it, inspect it, and possibly replace it?

[R2X]

Did you ever get this sorted out? I may be experiencing something similar. It's a noticeable reduction in power but the car runs flawlessly smooth. I haven't done any troubleshooting yet. This only happens sporadically and seems to return to full power the next time I drive it later in the day or the next day.

[dadysev]

Originally Posted by R2X

Did you ever get this sorted out? I may be experiencing something similar. It's a noticeable reduction in power but the car runs flawlessly smooth. I haven't done any troubleshooting yet. This only happens sporadically and seems to return to full power the next time I drive it later in the day or the next day.

Problem is the small Oring on the vanes solenoid, and not the solenoid itself. I just went through this and changed all the Orings. What a difference!