[shyne]

Hello!

I am trying to diagnose an issue I am having with a recently purchased car.

07 335i / N54
AT
01/07 Build Date
64k

Symptoms:

Red oil light:
Only happens at start up when it does happen… Hardly ever does it. Has to be really cold outside or car hasn’t been driven in days.
No codes, no difference in RPM, no difference in sound, nothing noticeable in drive.

28A7 and 3100:
Very irregular. Sometimes it will happen at startup, sometimes it will happen at mid rpm. Can’t replicate every time.

What I’ve done:
-Replace oil filter cap:
When I did my first oil change on the car, the center piece seemed like it had a lot of play in it. New cap does this too, still can’t figure out if this is normal.
Notes: It helped bring down the red oil light frequency down, as well as the time it spent on screen. I also noticed that the times I went to go take the cap off, there was never oil in there. To my understanding there should be an anti drain valve in place to prevent oil starvation at startup? Not sure if I’m onto something here.
-Removed VANOS solenoids:
I went ahead and got these out of the car and gave them a clean as lots of other threads have suggested. The car took the clean well as it stopped the codes all together for a couple weeks. Noted that one solenoid looks like it has been replaced already. One looked way more worn than the other.

I plan on doing my check valves next to see how they look.

Any advice or tips to where to go after? I’m about ready to throw a couple parts at it since I’m at that mileage.

VCG - I guess I could take a look at the cam ledgers and the cam gear bolts while I’m in there?
OFHG - Curious to know if this could have anything to do with the draining of the oil at the filter?

Also… One more note.. When I bought the car the previous owner had just replaced belts. My mind likes to create scenarios and I could only imagine a belt shred and got sucked up in the oil pan. Any way I could check this without dropping the pan for ease of mind?

Any advice or tips would be greatly appreciated! I hope to diagnose this properly and get the car running in top shape soon.

[shyne]

Hi all, I am returning with updates on the issue.

I found a TSB online addressing the issue.

The dealership isn't going to do anything about it so the only thing to do now was to follow the test plans strictly.

Needless to say I cashed out on FCP Euro.
-5W-40 Liquid Moly Leichtlauf High Tech & Mann Filter
-Vanos Solenoids, OEM
-Oil Filter Cap, OEM

I've had the parts sitting around for a bit while I worked up the courage to step outside in the cold to work on the car.

The oil is still fairly fresh, roughly 1100 miles on it. Inspecting the oil filter didn't really tell me anything. No debris, no metal, all clean just as it should.

Well I finished up all the work and got to start it up.

Red oil light.

When I first posted, it had been a while since it had done it last, but I felt it was necessary to include. Fast forward to today, still hadn't done it until this startup. It shows up for like 2-3 seconds and then when I cycle through my control it's never to be found. No codes no symptoms just a light. Weird.

I let the car idle to warm temp and nothing seemed out of the ordinary. Time for a test drive.

All it took was a few seconds on the road to realize how different the car felt. It now has a more responsive and healthy(?) feel. I did what was best for a fresh oil change and put the solenoids to work. Not only did the car feel way faster but the car felt smooth across the power band. No limp codes on this test drive.

The only bad out of all this is that while I was letting the car warm up, I was standing in front of the car with the hood up. What do you know!? Smoke coming from the headers and the horrible smell of burning oil!! Looks like I'll have to do my VCG after all. LOL

[bkwld]

Good info.
I wonder if it was the oil filter cap? I can see how they can be prone to damage over the years.

[TheMidnightNarwhal]

Originally Posted by bkwld

Good info.
I wonder if it was the oil filter cap? I can see how they can be prone to damage over the years.

Since OP replaced both solenoids I would bet it was one of the solenoids. The oil filter cap only needs to be replaced if the internal cage detaches and does not re-attach back.

A good way to test as well not in the TSB that is cheaper is to simply swap solenoids and if the code changes sides you know it follows the solenoid. If code doesn't move then it's probably oil filter cap, oil supply or cam bearing ledge.

That said the red oil light issue would worry me. To me that technically means you don't have enough oil pressure at start up. Idk if others can chime in. I've started my car in -20c and even colder on my other car and I never get a red oil light.

[shyne]

Originally Posted by TheMidnightNarwhal

Since OP replaced both solenoids I would bet it was one of the solenoids. The oil filter cap only needs to be replaced if the internal cage detaches and does not re-attach back.

A good way to test as well not in the TSB that is cheaper is to simply swap solenoids and if the code changes sides you know it follows the solenoid. If code doesn't move then it's probably oil filter cap, oil supply or cam bearing ledge.

That said the red oil light issue would worry me. To me that technically means you don't have enough oil pressure at start up. Idk if others can chime in. I've started my car in -20c and even colder on my other car and I never get a red oil light.

I did try to swap the solenoids but it was always the exhaust code that came back.
I will note that the original oil filter cap's cage was very loose. It had crazy amounts of play compared to brand new.

Since last post, I did get the code on one occasion only. Asked a friend who worked at BMW if he could give me some tips. Told me to erase the code and see what happens.. No code since. Took it over to the dealer so they could run some tests and they said everything checked out good.

Here's my plan moving forward:
-Inspect check valves (non-return valve). I'm interested to see how they look. If dirty, probably clean and/or replace.
-Valve Cover Gasket. I am interested to see how clean the internals look.
-Oil Sample Test. Just for piece of mind. I'm wondering if they'd be able to detect possible belt or bearing material.

I'm worried there is a clog at the oil pickup at startup causing the red light. But like mentioned before, there is no symptoms or codes to work off of. The tech at the shop said it could be oil pressure sensor or oil level sensor. If anybody has any diagnostic tips on that it would be much appreciated!

[shyne]

Update:

Since last post things have gone bad real fast. I just got two codes I haven't seen before.

28A2: vanos intake - 'A' camshaft position - timing over-retarded (bank 1)
2A98: crankshaft - intake camshaft, reference

I think I will be parking up the car until I figure this out. I was able to get the car home fine and it didn't throw any more codes after erasing. I still haven't tried the other things I had plan to further test.. But, I am almost convinced it is time for cam bearing ledgers. Will attempt non return check valves before this all gets real hands on.

I drove it 8 hours home after the car sat for a couple years, which brings the question if or not that may have anything to do with this now. I did get a check engine on my way home but I was determined to make this work from the start.

I will be looking out for sludge or metal, if there is sludge I may consider liquidmoly's engine flush as I am worried the car ran on old oil for too long. If there is metal I will dive straight into the cam ledger situation.

I have already tried getting BMW to help me out since the mileage is under 65k. Unfortunately I am too far past their extended warranty so I am left alone to tackle this. This will be my first major engine work done so this will be plenty fun. I will probably take this slow and investigate the wear before cashing out. Luckily, I have found a local junkyard that sells camshafts at $25 a piece, and other n54 guys selling cam ledgers.

Wish me luck!

[shyne]

It’s been a while since I made this thread. I wanted to update with my solution in case someone stumbles upon the same symptoms.

I had a hunch already that there must’ve been debris in my oil pan. Red oil light only on startup and vanos codes only on WOT.
I had already tried to get help from BMW and got nothing. The two possibilities I came down to were that either my cam ledge bearings were toast or I wasn’t getting sufficient oil pressure triggering my vanos codes. Seeing how the cam ledge job would’ve ran me a forture, I decided to go for a new oil pickup and see what I found in my oil pan.

I dropped the pan and found massive chunks of gasket material/belt. I found it suspicious that the last replacement on this car was a belt before they stopped driving it for a couple years.

Anyway, cleaned the pan, replaced the oil pick up tube and sealed it all back up. 5k miles later and it’s safe to say that the car has been running strong and the vanos code hasn’t returned since.
Cheers to another successful diag!