Ahoi gents,
I have been following the forum keenly over the years as a lurker, and hope someone here might have an idea whats up with my car. I have an early edition e90 320i with n46b20 engine.
The first symptom, is that when going wide open throttle or blipping, there is what sounds like either a misfire from the front cylinder, or the timing chain at the front hitting plastic.
At first, I thought it was the famous worn timing chain guide and tensioner wear, and low and behold, i find a piece of tensioner in the sump and the chain stretched and cam adjusters out of spec. I borrowed the timing lock tools, and do the whole thing, new guides, chain, tensioner and crank sprocket. The adjusters themselves looked OK, very slight wear, but nothing to fancy for a 14 year old engine. Turned engine several times by hand, all tools refit perfectly. I changed cam and crank sensors too. Cleaned out VANOS solenoids, tested with 12v supply, they click nicely, and new viton seals, as per the BMW weird imperial sizes from the factory.
New coils and spark plugs too, new oil pressure sensor and engine coolant sensor since i took it all off and they super cheap.
Now, I updated the DME to the latest version, because I also discovered something weird, my car did not come with a proper MAF sensor, it was just a clean "blank" maf housing with no electronics, and the car never threw a code, which i thought was weird, but i heard of other 320i also coming like this from the factory. I bought a new MAF, and I get readings now INPA, but even after updating to the latest ZUSB for the MEV946 ECU, it still doesnt care about the MAF![omg waiting]( "omg waiting")
The weird thing however is now, that nothing has changed, the engine runs smoother, but after doing a full Tool32 ram_backup to reset cam adaptation values, the result is always the same as before. Adapation for exhaust/intake always go to 40 degrees (max retard) and looking at the live values, the timing for both is read as always 120 advanced even if input signal is 5%, the input signal doesnt even change much anymore to the rpm of the engine, where before it did change but output still didnt follow.
I have also rebuilt the Valvetronic and the motor endpoint test always succeeds.
When I start the car for the first time after CAS/DME align, it cranks like mad for 30s or so, then finally starts and I can see how the adaptations go from the green zone in INPA, to the 40 point, and then it starts. I cannot make this loud "clacking" sound go away. Some mechanics suggested it is headgasket inter-cylinder leak between the front two cylinders and that I am eating away the engine block.
Honestly, Im not sold on the idea, but I am also scared. It runs alright like this, but I would love for everyhting to be right, I have invested tons of hours in labor and money to get everything right, and I feel somewhat defeated by this issue.
Any ideas or longshots welcome.
Thank you for reading![Bluebiggrin]( "Bluebiggrin")
!
PS: I had a leaky fuel injector o-ring on the rear cylinder at one point, and that made it make the clacking sound while i was just driving at normal speeds too ! Can low fuel pressure cause this ? I get no codes regarding vanos at all. I only get a code for EGR ZwangsShaltung, that I understand is related to the Oil level sensor on n46.
EDIT: I also have codes regarding one bank postcat lambda heater not performing well, can that supress the vanos system ? I have done all tests with the engine full hot, so I imagine the lambda sensors performing, since I get readings in INPA.
I have been following the forum keenly over the years as a lurker, and hope someone here might have an idea whats up with my car. I have an early edition e90 320i with n46b20 engine.
The first symptom, is that when going wide open throttle or blipping, there is what sounds like either a misfire from the front cylinder, or the timing chain at the front hitting plastic.
At first, I thought it was the famous worn timing chain guide and tensioner wear, and low and behold, i find a piece of tensioner in the sump and the chain stretched and cam adjusters out of spec. I borrowed the timing lock tools, and do the whole thing, new guides, chain, tensioner and crank sprocket. The adjusters themselves looked OK, very slight wear, but nothing to fancy for a 14 year old engine. Turned engine several times by hand, all tools refit perfectly. I changed cam and crank sensors too. Cleaned out VANOS solenoids, tested with 12v supply, they click nicely, and new viton seals, as per the BMW weird imperial sizes from the factory.
New coils and spark plugs too, new oil pressure sensor and engine coolant sensor since i took it all off and they super cheap.
Now, I updated the DME to the latest version, because I also discovered something weird, my car did not come with a proper MAF sensor, it was just a clean "blank" maf housing with no electronics, and the car never threw a code, which i thought was weird, but i heard of other 320i also coming like this from the factory. I bought a new MAF, and I get readings now INPA, but even after updating to the latest ZUSB for the MEV946 ECU, it still doesnt care about the MAF
The weird thing however is now, that nothing has changed, the engine runs smoother, but after doing a full Tool32 ram_backup to reset cam adaptation values, the result is always the same as before. Adapation for exhaust/intake always go to 40 degrees (max retard) and looking at the live values, the timing for both is read as always 120 advanced even if input signal is 5%, the input signal doesnt even change much anymore to the rpm of the engine, where before it did change but output still didnt follow.
I have also rebuilt the Valvetronic and the motor endpoint test always succeeds.
When I start the car for the first time after CAS/DME align, it cranks like mad for 30s or so, then finally starts and I can see how the adaptations go from the green zone in INPA, to the 40 point, and then it starts. I cannot make this loud "clacking" sound go away. Some mechanics suggested it is headgasket inter-cylinder leak between the front two cylinders and that I am eating away the engine block.
Honestly, Im not sold on the idea, but I am also scared. It runs alright like this, but I would love for everyhting to be right, I have invested tons of hours in labor and money to get everything right, and I feel somewhat defeated by this issue.
Any ideas or longshots welcome.
Thank you for reading
!PS: I had a leaky fuel injector o-ring on the rear cylinder at one point, and that made it make the clacking sound while i was just driving at normal speeds too ! Can low fuel pressure cause this ? I get no codes regarding vanos at all. I only get a code for EGR ZwangsShaltung, that I understand is related to the Oil level sensor on n46.
EDIT: I also have codes regarding one bank postcat lambda heater not performing well, can that supress the vanos system ? I have done all tests with the engine full hot, so I imagine the lambda sensors performing, since I get readings in INPA.