Sudden Running Poorly and Then Not?

[razorboy]

Hey Lads,

Troubleshooting what could be an intermittent issue on the X5. Getting frustrated with this truck. It seems to line up work so that as soon as I fix one thing (recent waterpump replacement - 2nd in less than a year), the next job is ready to go. My wife can't stand the thing and doesn't trust it to go anywhere and I am starting to wonder myself.

So for a while now the truck would occasionally oscillate around idle. Stopped at a light and the idle would go up and down by a few hundred RPM. Nothing dramatic but annoying. This was only occasionally. Most times the idle is rock solid.

Again, very occasionally the truck would stall out going around corners. Usually due to rapidly lifting the gas and applying the brake. Only happens once in a while and I found that it would not do it when the truck was in the sport mode on the shifter although this consumes more fuel and the shiftpoints are higher. Not what I want for around town driving.

So today I was bringing my son back from school and pulled up to a stop sign and the idle starting doing its thing but it felt like the truck was going to stall out. I gave it a shot of gas and it sounded like it was running on 4 cylinders and immediately the check engine light came on. As I left the stop sign all the way back to my house, it was running on what felt like 4 or 5 cylinders and stalled out going around the corner to my house. I started the truck and it was the same. Nursed it back to the driveway.

I got my scanner out and it has a P0011
A camshaft Position
Timing Over advanced or system performance Bank 1

I left the truck for a couple of hours and just went out and it started perfectly and idled perfectly. The issue has disappeared. Check engine light is still on though.

Does this sound literal meaning that I may have a faulty cam position sensor?

I know how these codes sometimes don't point directly to the problem. Just wondering if this is an issue that others have experienced.

Thanks
Bernie

[Joshdub]

What engine do you have?

[CapeX5]

CPS going bad?

[jfoj]

Assume you have a 3.0 I6?

Initial guess would be intake camshaft position sensor.

But here is the problem often with cam timing codes.

Is the problem due to the cam sensor or due to the VANOS control solenoid.

This gets a bit tricky. What came first the chicken or egg?

Given the age of these vehicles sensors do go soft and are important to keep things operating correctly.

So if it was me, I would replace the intake cam sensor first and then see what happens.

Some might start with the VANOS solenoid.

Often people make their decision based on economics. Replace the cheaper part first and hope for the best.

Some people make their decision based on the easier or quicker part replacement.

[razorboy]

Thanks guys,

Yes, I have the 3.0 straight 6

Ok, I will do a little research on both the sensor and the solenoid.

Is it safe to say that the code is accurate enough to zoom in on these two potential issues?

I just hate throwing parts at a problem.

Cheers
Bernie

[razorboy]

Where is a good resource for buying these sensors?

The prices range from 12.00 - 125.00
lol

[SlickGT1]

Dealer.

Check connections first. I had some weird shit happening once. Forgot which sensor. Turned out the connection wasn't fully seated. Every time I turned check engine popped out. Took off engine cover to dig around, click on the sensor electrical connector, and no more issues.

[jfoj]

You do not need to buy the sensors from the dealer, but you want the same manufacturer as the OE sensors.

Use BMW Parts Catalog to find the part number, then put the part number in this tool for pricing info - BMW Part Number Price Comparison for Windows & Mac

[jdstrickland]

I'm with jfoj, with a caveat.

P0011 means that the variable timing is at full advance all of the time. If the VANOS mechanism was merely stuck, and later was not stuck then this would explain the symptom. I'm not sure what it takes to look at the VANOS (variable valve timing mechanism), but it is driven by oil pressure and reverts to the original position by a spring. If the device was compromised with tarnish, then this code would reasonably be the result.

If you can take the VANOS apart and clean it, then put it back together, you should be able to cure this one without buying any sensors.

I'm thinking this problem is something akin to a sticky lifter. You can hear the lifter because it fits loosely in the space between the cam and the rocker arm due to tarnish that prevents it from refilling as quickly as it is supposed to -- the VANOS sticks at full advance because the tarnish does not allow it to return to its home position.

[jfoj]

I cannot recall if Hella is the OE supplier of the cam sensors or not?

I am sure someone can confirm id this is or is not correct.

FCPEuro offers OEM Supplier which they claim is the OEM supplier for the original sensors.

I find the cam sensors are Hall Effect and if they have problems determining the cam position, then you can get an over or under advance situation.

It looks like the intake cam sensor is around $50 for a Hella or OEM from FCPEuro, so this may be the cheapest and easiest place to start.

If find cam sensors get sloppy after close to 10 years as well.