[MasterDuke]

Hey guys, I have a possibly unique situation going on. If you look at my previous posts, you can see that this car has been a project for a while. It is in a much better state than when I first got it. It starts, runs, and shifts smoothly for the most part. Aside from a couple of random codes that get thrown at me, this car always had a rough idle since I got it. There were a multitude of issues that needed to be attended to first before I tackled that, i.e. alternator, transmission valve body, rewiring fuse box, fuel pump, ABS/DSC, etc. The car had water damage.

I drove the car up and down the road for a bit, approx. 10 miles, and the transmission jumped into limp mode and SES light went on. Strangely, it didn't stay on 3rd or 4th gear. It ran like normal, just shifted a bit more aggressively. I was just getting home anyways so I checked out the codes and I have:

1. P0011 28B6 value above threshold
2. 3C1E implausible value
3. 28A2 value above threshold
4. VANOS intake stuck at ~126 degrees and exhaust at ~-101 degrees
5. 145 and 146 transmission codes

Now, after some research, it seems to be related to the MAF sensor for the most part. I cleaned it with MAF cleaner. Worked only for a bit, probably didn't change anything. I replaced it with a known good replacement. Same result. I am thinking that I either got a bad part, or that my VANOS is the issue. Based on how the car was when I got it, it seems like the previous owner didn't know how to keep up with the maintenance. I am assuming that the seals are the original. At 139k miles, if they are original, I would be surprised they held up for this long.

Here are a list of things that I have already checked out: DISA (seal and the unit itself), cam intake sensor, MAF sensor, intake gasket, intake smoke test, ICV and continuity between the lines and the control units. I am leaning towards this being a VANOS issue. I remember reading that these positions that the VANOS is stuck at is the failsafe position. In terms of the codes listed above, do you guys think I missed something? What do you think this issue can be? Thank you ahead of time for any input or advice!

 

[NZ00Z3]

Did you use a good quality inlet cam sensor? Cheap aftermarket ones are hit and miss.

Have you cleaned the VANOS solenoids? They may be gummed up and causing the mechanical code.

As you have done a smoke test and chased vacuum leaks, check you hot idle fuel trims. If they are all below 8%, then unplug the MAF and see if the engine runs better. If you have an auto transmission, then you'll get a "COG" warning light. Don't worry, it'll all go back to normal once you plug the MAF back in. If the engine runs better, then you have a duff MAF.

If any of the fuel trims are still above 8% at hot idle, then you have vacuum leaks to find.

 

[Bali]

Some of your fault codes are decimal, so convert them to hexadecimal then look up their descriptions on the bmwfault.codes website.

MS45.1 DME

• 28B6 (P0011): Inlet camshaft: mechanical
• 3C1E: Inlet camshaft sensor: signal
• 28A2: Air path: monitoring

GS20 EGS

• 91h (145): CAN torque reduction
• 92h (146): CAN torque interface

 

[MasterDuke]

Interesting, I will definitely check out that link when I get a chance.
As per the previous questions:

Did you use a good quality inlet cam sensor? Cheap aftermarket ones are hit and miss.

I believe it is from Holstein. I can't remember correctly but it was reasonable for the cost with warranty. Will most likely change it because it's not OEM or OE.

Have you cleaned the VANOS solenoids? They may be gummed up and causing the mechanical code.

When I saw this I jumped right into it since it's quick and pretty simple. I did notice some sludge at those points. Nothing crazy but, in my opinion, any sludge is not good. I did notice that it was binding a tiny bit returning from it's lowest position, but rides like butter otherwise. That was for the intake, exhaust was no issue at all.

If any of the fuel trims are still above 8% at hot idle, then you have vacuum leaks to find.

This is a great point. I will definitely check that whenever I get a chance and do a follow up afterwards.

I am currently waiting for a new PCV/CCV system (a good amount of oil coming from it), then I will diagnose deeper into it. Come to think of it, is it possible that the oil from a bad PCV/CCV system could get oil onto the MAF sensor and cause misdiagnosed codes? It's just a thought but I'm curious to see if that would change anything. I am doubtful because of how high up the MAF sensor is in the intake system but, if it's really bad, it could possibly cause issues? I will definitely follow up with any changes. Thank you both for the advice.

 

[MasterDuke]

Hey guys, I have a mini update to share. I did check my hot idle trims and they are holding at -8% on both banks. Even giving it gas doesn't change it. I definitely agree that my MAF is faulty. I just ordered an OEM MAF and cam sensor. Hopefully this clears it all up, will definitely update on any changes.

 

[MasterDuke]

Here's a mini update. I have replaced the MAF sensor with a VDO/Continental from FCP. I definitely feel more power right off the bat but when I accelerate past 3k RPM, it goes straight into limp mode with code P16A7: 28A2. I was going through the forums and this is what I have done so far.

I did a back pressure test before the cats, no issues there.
Ran with the pre-cat O2 sensors out, still went to limp.
Drove with MAF unplugged, hard shifting but no limp.
There are no vacuum leaks, did a smoke and 'spray carb cleaner" test.
Ran with the old MAF sensor with/without O2 sensors, still entered limp.
I don't know if this warrants opening a new thread but I am assuming that I just got a bad sensor. I'm doing a warranty swap with FCP just to be safe. I'm also going to double check the continuity between the MAF connector and DME and the fuel pressure while at idle and under load in the meantime. I'll report back with my findings.

 

[MasterDuke]

Alright, I got some more information to see if we can pin point this. I did the fuel pressure readings, at the fuel rail, I have ~60 psi at idle with no change at higher RPMs. That seems pretty high but I'm not 100% sure off the top of my head if this is within normal range for this motor. I am attaching some freeze frame data and live motoring data. Once again, thank you for any additional help. I will continue to do more research in the mean time.
Some of the freeze frame codes are from removing different parts, specifically the pre-cat O2 and MAF sensors.

 

[NZ00Z3]

What model of E46 do you have?

Does it have a SULEV (M56) engine?

The M54 should have a fuel pressure of 51 +/- 3 PSI
The M56 should have a fuel pressure of 72 +/- 3 PSI

Your fuel pressure value of 60 PSI is in the middle, so we don't know if it's high or low? You need to confirm the fuel pressure test result.

An overly high fuel pressure will cause negative fuel trims. If you are truly getting 60 PSI and you have a M54 engine that needs 51 PSI, then the engine will be injecting too much fuel per injector pulse. This results in negative fuel trims, which can be seen in your multiplicative (long term) trims. You need to confirm the fuel pressure test result.

Your engine is drawing 23 kg/h or 6.4 g/s of air at hot idle. That's way too high. Your MAF is over reporting. An over reporting causes negative fuel trims. This can be seen in the Multiplicative (long term) values being negative. either the MAF is faulty of the MAF signal is being corrupted. Check for oil or coolant contamination in the DME connectors, especially the large one in the middle.

 

[MasterDuke]

Using realoem and just my experience at the intake system, I can confirm that it's a M54. It is a 2005 330i. I will double check in the morning that I do indeed have ~60 psi. One thing to note is that I noticed at the beginning of the test, after it was sitting all night, the pressure was at practically 0 psi. This is what I found on my research. This gave me some idea on what was going on; your post just validated my suspicion. My theory is that the FPR either died, not connected properly or there's a break in the line somewhere in between. I had COVID multiple times and I cannot smell gas at all. I will most likely need someone to use their good nose for me to find out where this is coming from. In terms of the connectors, they are all clean. I still need to do a continuity test from the MAF to it's respective points. I will most likely do this along with the second fuel pressure check.

 

[MasterDuke]

So I found some fuel leaking from the connection point at the end of the fuel filter to the fuel rail. It's possible that I just loosened it up when I took the bracket off but I'm going to replace those hose connection in the morning. I confirmed a second time that the fuel pressure is at ~60 psi. Here's what's interesting though. I moved the 'vacuum line' from the small hose on the F connector to the line towards the back of the motor. The one that connects to the vacuum canister; the previous owner deleted that canister and plugged the line. I checked the pressure and it dropped to ~50-55 psi. Now my question, is that line just a vent line or a vacuum line? I have read that many places refer to it as a vacuum line but I remember reading several posts about it being just a vent line. I did not drive the car with that set up yet but I did not see any differences to the fuel trims and the MAF readings. I may replace that line as a whole anyways since it's cracked at the connector for the FPR. This filter is a recent replacement from Bosch and the pump is new from Bosch as well. To my knowledge, there is no regulator at the pump. It should just be a level sender and pump combo, correct me if I'm wrong. I feel so close to having this car perfect, I would hate to give up now.

 

[NZ00Z3]

The line from the Fuel filter/regulator to the "F" connector is a vent tube. @MrMCar confirmed this a while back. It should be clear to blow through when both ends are taken off. Check the "F" connector to make sure it is not blocked.

The 2005 330i has the 6 pin MAF. It includes the intake air temp sensor as well as the Hot Film MAF (HFM). You are getting two codes for the MAF and an intake air temp sensor error. There is something going astray with your MAF.

• Loose connector pins/connectors
• Damaged insulation
• Broken wires

 

[MasterDuke]

I knew I forgot to add something, I did do a continuity test. All pins are good. Did do the wiggle test as well to see if the connection is spotty but no noticable change.

 

[Bali]

I moved the 'vacuum line' from the small hose on the F connector to the line towards the back of the motor.

Put that air line back on the F connector on the intake boot. It is not meant to have any vacuum on it.

Do you know if the fuel pressure gauge is accurate? If yes, then your fuel pressure regulator may be caput. Fuel pressure must be near 50 PSI.

 

[MasterDuke]

Put that air line back on the F connector on the intake boot. It is not meant to have any vacuum on it.

Don't worry, I didn't drive it like that. I just wanted to see how the fuel pressure would change compared to just the vent. It did seem to improve but it might not be directly related to that issue rather masking a different issue.

Do you know if the fuel pressure gauge is accurate?

I am fairly confident on the accuracy of this gauge. I have used it many times for different applications and it is consistently within a 1-2 PSI threshold.

You are getting two codes for the MAF and an intake air temp sensor error. There is something going astray with your MAF.

I am not sure if I stated clearly but I did swap between the two MAF sensors, the known bad and the new one. Those HFM codes did not reappear when I put on the new MAF sensor. The reason why I swapped between the two was so I can compare the two. The new one, despite reading too much air, is steady and consistent; while the old one would jump like crazy then eventually drop to zero, following the transmission codes and the HFM codes.

I definitely suspected a loose connection. I did do the 'wiggle' test to see if the readings changed while running, no change. As stated previously, the continuity is okay on all ends and their is no grounding in those lines as well, aside from the one ground line in there.

Mentioning previously:

So I found some fuel leaking from the connection point at the end of the fuel filter to the fuel rail. It's possible that I just loosened it up when I took the bracket off but I'm going to replace those hose connection in the morning.

I did pull the line connection and there is indeed mini cracks in that line. My local auto parts store does not have a replacement but I already ordered one on amazon that is rated for injection. Once I have that reinstalled, I will go ahead and do the other connection points as well. Not that it needs it but I would say its good preventative maintenance if you have extra line. I am also replacing the vent line for the FPR. I am not sure if it is like this for all 330i or E46 but it changes from the connection point to a reduced line up until the F connector. I am going to make it one sized line all the way through. I believe that it may be causing a restriction in the flow, which could be part of the issue as well. I definitely think that my air flow issue is directly connected to the fuel pressure. It does make sense when you think about it, the car doesn't think like that. More like more fuel = more air and when it's already topping out, it can't provide anymore causing the crash.

If changing the lines doesn't correct the issue, then I will replace the FPR and go from there. I will definitely continue to update as I get more information.

 

[MasterDuke]

Alright, it has been a bit and I have updates.
I changed the FPR, now the fuel pressure is back to a more appropriate level. This did not fix the issue. MAF is still reading ~6 g/s at hot idle and fuel trims are still at -8%. Vehicle is still entering limp mode once 3k RPM is hit. I just sent out the MAF sensor for replacement through FCP. Here's hoping that works because I am not sure what else I can do to correct this, aside from bringing it to a shop.

 

[Sapote]

This did not fix the issue. MAF is still reading ~6 g/s at hot idle and fuel trims are still at -8%.

specify the vehicle

 

[MasterDuke]

Without specify the vehicle, this MAF flow rate of 6g/s is correct for a 1967 Super Tessy.

The vehicle is in my profile, but for redundancy sake, it's a 2005 330i. KM42269 is the last 7 digits of the vin if you look at realoem for the parts. I'm just waiting for a replacement from FCP, I read that getting bad parts is not uncommon, even with OE/OEM. With all the testing that has been done, it's the only thing that makes sense.

 

[Sapote]

The vehicle is in my profile, but for redundancy sake, it's a 2005 330i.

No one needs to look into your profile to find out what car you're asking for help. It's like "Doctor, just call the city hall and they will pull out my birth certificate and tell you my DOB."

MAF is still reading ~6 g/s at hot idle

Hot idle at what rpm? Not all cars are idling at 700rpm, unless they are all running perfectly normal. 6g/s is too high even for 3.3L engine.

 

[MasterDuke]

No one needs to look into your profile to find out what car you're asking for help. It's like "Doctor, just call the city hall and they will pull out my birth certificate and tell you my DOB."

Okay.

Hot idle at what rpm? Not all cars are idling at 700rpm, unless they are all running perfectly normal. 6g/s is too high even for 3.3L engine.

Of course it's not perfectly at 700 RPM, it's like +/- 15 RPM consistently. Not erratic by any means.

 

[Sapote]

Okay.

Of course it's not perfectly at 700 RPM, it's like +/- 15 RPM consistently. Not erratic by any means.

Impossible for MAF to read 6g/s at that rpm. Must be some bad electrical wirings issue to cause such a high offset.