just inspected/passed, now throwing codes at me

[workingonit]

I've just received the new non-OEM "Camshaft Position Sensor" (exhaust side) to replace the one currently giving me the P0365 codes (twice, only recently). I haven't pulled the one on the X5 yet, so I don't know if it's a BMW part, a crappy Chinese replacement (though I've found some Chinese knock-offs OK, but not many), or cracked/broken or what?....

While researching sensors online, I've decided it's a crap-shoot, so I at least tried to get a "German-made" part. If it is indeed made there, oar in a German-supervised plant, it probably will work OK. Actually, I've always had better-than-average luck with European parts, so far, especially German (but I'm glad I didn't have British "Lucas" or Italian "Magneti Marelli"electrics to deal with, back then).

I've had many personal vehicles (25+) before, and worked on dozens more, and only had one unexpected failure (not wear items) with a German part, the Bosch K-Jetronic FI on my '73 Volvo 142. I really believe it was the Volvo tech that screwed it up, though.

And because I've had more GM vehicles than all other combined, I've become accustomed to AC-Delco/Delphi/GM parts go from being all made-in-the-USA, to coming from all over.

Anyway, here's what I received, and plan to install in a day or so; hope it works as a good German part should.

[crystalworks]

Looks like you need a cam sensor and to clean the IAC valve. They rarely fail outright, but do commonly get gummed up which cleans up just fine with some carb cleaner or like solvent.

[ahlem]

How much fuel is in the tank? I had similar codes and the solution was a 99 cent O ring in the siphon pump pickup. (Thanks Andrew Wynn) If you have less than 1/3 tank, that might be something to check out and look at the dash codes.

[workingonit]

Originally Posted by ahlem

How much fuel is in the tank? I had similar codes and the solution was a 99 cent O ring in the siphon pump pickup. (Thanks Andrew Wynn) If you have less than 1/3 tank, that might be something to check out and look at the dash codes.

Since I got my X5 in May, with a 1/4 tank in it, I've never let the tank go below 1/2 full. My first drive was to the gas station where I filled it with 93 octane. I've topped it up twice since then, in late October before the state inspection, and in December, to get some "winter gas" in it.

I've only put <400 miles on it since I got it; about 200 before the first codes appeared in early November, after the inspection, and the rest of the miles since then, along with repetitive codes. At no time did it get below 1/2 tank.

However, I have seen the SES light pop up just after I've made a hard right turn (3 times, at the same intersection where I have to avoid getting rear-ended), and once more when I made a hard left acceleration onto the freeway, avoiding an idiot that tried to enter in front of me from a side street. Is the fuel moving away from the siphon pump pickup?, or is something else in the tank associated with the codes?

The freeze frames I've recorded show info that corresponds with those incidents; I use Torque Pro full-time on my dash-mounted spare Android phone to monitor my fuel trims to see if anything goes haywire, but the trims stay pretty consistent, close to the reported freeze frame info. They're always a bit high, but I don't know what other X5's with M54 engines get for fuel trim readings.

[workingonit]

Originally Posted by workingonit

...I have seen the SES light pop up just after I've made a hard right turn..., and once more when I made a hard left acceleration onto the freeway.... Is the fuel moving away from the siphon pump pickup?, or is something else in the tank associated with the codes?

The freeze frames I've recorded show info that corresponds with those incidents;the (fuel) trims stay pretty consistent, close to the reported freeze frame info. They're always a bit high, but I don't know what other X5's with M54 engines get for fuel trim readings.

I've put another 100 miles on the X5, all short hops around town (my BC shows the average speed at 19.5mph, and fuel usage at 15.0mpg), so my conjecture above is mostly correct, that my P0171 & P0174 (and sometimes a P0313) codes occur at low-speeds/sharp turns/rapid deceleration.

The fuel trims are now quite consistent, with long-term on both banks (the same reading on both) at 11.72 (sometimes at 10.94), while the short term readings are now mostly in the negative 2-6 range (the bank 2 is closer to zero than the bank 1). From what I've been reading about fuel trims, mine aren't too bad (I've yet to see examples from another M54, though).

Today I tried the smoke tester again, with no smoke visible, as usual. I'm going to try spraying carb cleaner next, since I must not have good enough eyesight to detect the vacuum leak that way. My Torque Pro app will tell me if the idle speed changes, even if it's so slight my (bad) hearing can't detect.

At what point should I look into the fuel system, if I can't find a vacuum leak? The fuel filter is < 3 years old, and I can't smell any fuel leaks anywhere (not really a possibility?). I'm also going to take off all the intake boots and replace them over the nexy six months before inspection is due.

[workingonit]

Originally Posted by workingonit

...The fuel trims are now quite consistent, with long-term on both banks (the same reading on both) at 11.72 (sometimes at 10.94), while the short term readings are now mostly in the negative 2-6 range (the bank 2 is closer to zero than the bank 1). From what I've been reading about fuel trims, mine aren't too bad (I've yet to see examples from another M54, though)....

Set the three codes again this morning, but also observed momentary short-term fuel trims of plus 10.5 to plus 11.7 (falling back quickly to plus 2 to plus 6), while the long-term fuel trims remained at 11.72, as usual. This was on my Torque Pro app, which didn't record a freeze-frame; I haven't looked with either of my hand-held scanners, yet.

Once again, I have no comparison standard to measure against, because I've yet to find what fuel trims are normal for a M54 engine. What do you guys normally see with your 3.0i engines?

[Effduration]

I've done a lot of fuel trim sleuthing on my E53, E46 and my E39...The e46 folks have really done a great job documenting all this. You want to get the OBDFusion app and set it up exactly as outlined here:

http://forum.e46fanatics.com/showthread.php?t=897616

as for your specific question...here is a response on the E46 site from JFOJ who pushed the envelope on fuel trim testing:

...Real world advice from BMW and many other vehicles.

Long Term Fuel Trims are the most important value to pay attention to in addition to the engine operating temperature. Short Term Fuel Trim values are ALWAYS changing rapidly and they need to me mentally averaged. They are less of a concern or value that I pay attention to, but these do come in handy for the final analysis of a problem, usually when pinpointing bad MAF's.

These comments are ALL about LTFT values.

Anything between 0% and +2.5% is fine, anything above +2.5% should be investigated.

Anything negative (-) or above +5% is a problem in my opinion.

Anything +10% or greater will typically trigger lean codes. Not sure if +12% is the magic number, but even +10% is an issue.

Be VERY CAREFUL when using any of the "German" software tools, even BMW Scanner, along with INPA, GT1 and so forth. This does not apply to Fuel Trim valves, but where the tools describe or use the terms Rich or Lean. There is either translation problems or a different point of view as to how these tools represent lean and rich conditions. They are usually 180 out of phase as to how the rest of the world view things. So for any of the software tools that are primarily BMW specific, you have to stop and take a LONG breath and THINK when you read CAREFULLY when you see the word Rich mentioned with any code.

RARELY do engines run Rich, they almost always run Lean. Very few situations can cause an engine to run rich, the 2 most common ones are engine operating temperature too low and fuel pressure too high. Even then, these situations RARELY trigger a code for a Rich condition. You will only pick this up with negative (-) fuel trims. Also MANY of the negative (-) fuel trims are MISLEADING. Usually due to a bad or counterfeit sensor.

Also DO NOT jump into replacing O2 sensors for Fuel Trim issues initially.

If the O2 sensors have issues, they WILL NOT usually trigger lean conditions, as the O2 sensors are what actually MEASURES the amount of Oxygen left in the exhaust stream. If the O2 sensor is not working properly, then how can it measure something that is 10% out of range?

[workingonit]

Originally Posted by Effduration

...Real world advice from BMW and many other vehicles.

Long Term Fuel Trims are the most important value to pay attention to in addition to the engine operating temperature. Short Term Fuel Trim values are ALWAYS changing rapidly and they need to me mentally averaged. They are less of a concern or value that I pay attention to, but these do come in handy for the final analysis of a problem, usually when pinpointing bad MAF's....

Thanks, Effduration, for that link; I've downloaded it to my phone as a .PDF file, so I can study it awhile. Previously, I've been watching YouTube videos from "50sKid" about testing BMW vacuum leaks via fuel trims.

I see that my previous focusing on intermttent short-term variations distracted me from the real problem...the excessively high long-terms. What got my attention mis-directed was the fact that the STFT1 kept going away (on both my Torque Pro and OBDLink apps....OBDLink app is another form of OBDFusion, made by the same people). I ran the sensor tests on the Torque Pro many times, and all the sensors were check-marked. Then, about two weeks ago, STFT1 reappeared on the display.

Like I said before, both LTFT readings have been steady and the same for the two banks, initially always at 10.9, then at 11.72, and sometimes at 10.5. All these high readings are completely way above any I've ever seen while working on other vehicles. With readings like these, I should be seeing:

• 1) a large vacuum leak, which should also be hissing enough to notice, that my smoke tester should've found already,
• 2) low idle vacuum, certainly under the 24 lbs @ 710-725 rpm that I always have,
• 3) obvious fuel-rich exhaust fumes, where there are none,
• 4) though the P0313 code indicates misfires, there has been no discernable evidence that I can feel (I've always been good at noticing misfires), and
• 5) the CCV seems OK, with good vacuum (& no Mayo) at both oil filler cap and dipstick

.
However, when I checked underhood about an hour ago, I did find that there was oil blow-by on the valve cover, never before seen, and not there when I did the "check the filler cap & dipstick for vacuum" test last week. The cap was very hard to remove at that time, so I guess it's time for a new seal there.


My Foxwell showed the usual two KOMBI codes that are always present, but the two DME codes were worded differently than before


At this rate, I'm starting to believe that the X5 will have to start showing unmistakable signs that can't be ignored, and I can SEE what's amiss. I'll have to use the smoke tester with stronger smoke fluid, and/or use carb cleaner on all the vacuum and intake rubber, and completely remove (again) my freshly rebuilt (with the GAS kit) DISA, and test the IAC again, as well. Otherwise, it's just parts cannon time.

Boy, do I miss those days where fuel, air, spark were easier to manage, by using simpler tools (vacuum/pressure gauge, tach/dwell meter, timing light, and a few hand tools).

[Effduration]

Check the entire CCV system...including drain to oil dipstick tube...it clogs easily, although in Texas, it should generally be clear of mayo..

A very small vacuum leak could lead to the elevated LTFT's you have. I don't know how you are smoke testing. But I can tell you a smoke test looking for a +10% LTFT needs to be a lot of smoke under pressure and you need to smoke from intake boots, brake booster, etc...

Check the rubber caps on your intake..there is one on the CCV valve and 1-2 on the rear of the intake near the firewall. The fact that you have similar LTFT's on banks 1 &2 tells me the vac leak is likely before it gets into the intake...

[workingonit]

Originally Posted by Effduration

Check the entire CCV system...including drain to oil dipstick tube...

a smoke test looking for a +10% LTFT needs to be a lot of smoke under pressure and you need to smoke from intake boots, brake booster, etc...

Check the rubber caps on your intake..there is one on the CCV valve and 1-2 on the rear of the intake near the firewall. The fact that you have similar LTFT's on banks 1 &2 tells me the vac leak is likely before it gets into the intake...

I haven't yet taken a close look at the plumbing under the beauty cover; out of sight, out of mind. I'll use my cheap Android borescope to take a close-up look under the manifold.

My smoke tester is homemade, very low pressure, and probably not up to the job. I have to either buy a better one, or get better smoke-making fluid.


I'm totally unaware of the vacuum hose routing on the M54...it took me many years to even learn of all the hoses on my older American cars (even though I replaced most all of them, over the years), and I have no idea where BMW has hidden them in their over-engineering way. I'm gathering photos of hose routing from the internet.


I can see how this is going to end...I'll have to try another smoke test, then a carb cleaner spray test, then the borescope examination, then a total removal/replacement of any or all rubber parts (plastic too, since BMW loves plastic, even moreso than General Motors). Been there, done that before, but never on an X5. That's why I keep five cars on hand, just in case.

the vac leak is likely before it gets into the intake
So, it could be from the SAP, CCV, fuel filter/pressure regulator, manifold rear, brake booster, etc., and parts & places unkown. I've got a hand drawing from another E46? website showing more possibilities (I'll find hidden treasures while I'm searching, I'm sure). I was hoping not to take it all apart so soon....