Low mileage 7 year N52B30 pinking - any solutions?!

Pinking Update - well BMW have acknowledged that this engine pinking is not right - at least that is something. The car is still with BMW to fix a fault that showed up on the diagnostics that could cause this. From my understanding this is something to do with the catalytic converter causing something to kick in prematurely, maybe linked to the knock sensor???. Not sure exactly what, but will know more tomorrow when they replace the part under warrantly. Glad i got this BMW from a main deaaler with full BMW warranty.

Will post further techincal details tomorrow. We will get to the bottom of this.

Originally Posted by S900ADY

Pinking Update - well BMW have acknowledged that this engine pinking is not right - at least that is something. The car is still with BMW to fix a fault that showed up on the diagnostics that could cause this. From my understanding this is something to do with the catalytic converter causing something to kick in prematurely, maybe linked to the knock sensor???. Not sure exactly what, but will know more tomorrow when they replace the part under warrantly. Glad i got this BMW from a main deaaler with full BMW warranty.

Will post further techincal details tomorrow. We will get to the bottom of this.

Interesting and reassuring development! Keep us updated! Will also once I get my car's codes read! If in my case it is the catalytic converter, then decat will make sense...

The 325i is back from BMW. They wouldn't tell me what the exact code number was but they diagnoosed the following under warranty. The following is the exact words stated on "Work Carried Out Invoice from BMW:

Carried out investigation into engine pinking under light/hard load.

Found fault with NoX catalytic convertor. Prematurely aged causing gases to not disperse as should. Replaced complete convetor unit. Knock sensor checked & tested with no fault code found. Re-tested and test driven with no engine pinking heard at point of repair.

I must state that this has significantly reduced my engine pinking to a point where you can accerlerate under hard or light load through all gears and not hear the horride "pink" i was experiencing. However, saying that, i did accerlerate hard in third gear at low revs (about 1000) and heard a couple of light pinks, but this soon stopped which i can only assume the knock sensor cut in and adjusted the timing to suit. She then accerlerated without a pink heard up to 5000 rpm. I had to stop at this point due to a car pulling out on me - typical!!.

Overall i am happy that this has reduced the "pinking", but will keep an eye on this as my ear is so trained now to that horrid noise.

I hope this info helps others that have experienced this with their BMW.

In the event that this does come back, fingers crossed it doesn't then i will post more. In the meantime i will still be looking at this thread and will be posting on others if i experience any other concerns with this 325i.

Originally Posted by S900ADY

The 325i is back from BMW. They wouldn't tell me what the exact code number was but they diagnoosed the following under warranty. The following is the exact words stated on "Work Carried Out Invoice from BMW:

Carried out investigation into engine pinking under light/hard load.

Found fault with NoX catalytic convertor. Prematurely aged causing gases to not disperse as should. Replaced complete convetor unit. Knock sensor checked & tested with no fault code found. Re-tested and test driven with no engine pinking heard at point of repair.

I must state that this has significantly reduced my engine pinking to a point where you can accerlerate under hard or light load through all gears and not hear the horride "pink" i was experiencing. However, saying that, i did accerlerate hard in third gear at low revs (about 1000) and heard a couple of light pinks, but this soon stopped which i can only assume the knock sensor cut in and adjusted the timing to suit. She then accerlerated without a pink heard up to 5000 rpm. I had to stop at this point due to a car pulling out on me - typical!!.

Overall i am happy that this has reduced the "pinking", but will keep an eye on this as my ear is so trained now to that horrid noise.

I hope this info helps others that have experienced this with their BMW.

In the event that this does come back, fingers crossed it doesn't then i will post more. In the meantime i will still be looking at this thread and will be posting on others if i experience any other concerns with this 325i.

Okay, that's very interesting! Keep us updated as to how the car behaves over the next few days or week etc! Pity they would not reveal the errors that came up!

Im pretty sure the noise I am hearing is the same problem as yours... Same age car except its a 330. I don't have a warranty so I'm worried how much this will cost me...i take it you had an extended warranty of some sort. How much without the warranty for the knock sensor check and the cat replacement?

Originally Posted by 8355adam

Im pretty sure the noise I am hearing is the same problem as yours... Same age car except its a 330. I don't have a warranty so I'm worried how much this will cost me...i take it you had an extended warranty of some sort. How much without the warranty for the knock sensor check and the cat replacement?

Best is to have diagnostics read and see what comes up - if it is simply the knock sensor then that's actually a pretty reasonable fix! I enquired about the cost from the agents and it was something like the cost of a few tanks of fuel. But bear in mind that you also need to replace the two aluminium torx screws that hold the sensor probes onto the side of the engine.

The best thing to do is give BMW a buzz and ask how much a cat converter would cost. But before that take Three Thirty I's advice. The only thing that i am sceptical about with BMW is that they may not tell you the full truth with error codes. This maybe my experience lately with mine or it's that this engine does suffer numerous things that BMW may try & cover up!!.

Originally Posted by S900ADY

The best thing to do is give BMW a buzz and ask how much a cat converter would cost. But before that take Three Thirty I's advice. The only thing that i am sceptical about with BMW is that they may not tell you the full truth with error codes. This maybe my experience lately with mine or it's that this engine does suffer numerous things that BMW may try & cover up!!.

And this is why with my car just out of motorplan I want to have the diagnostics read privately so that I can see for myself, and also to see if it can show any timeline as to when these errors occurred - my car was in at the agents while under motorplan for this very problem, and all they did was update software and inform me that it is "normal" for the car to pink! Yeah, right! Now I will bet you, take the car in to them and all of a sudden all of these errors will pop up and this and that has to be replaced at my cost... See where I am going with this?

Anyway, once I can find someone who can read my codes I can take this further - as far as I know, new cats are not going to be cheap, so in my case if it is the case, will rather do away with them and decat, freeflow exhaust etc... Then maybe later on treat my car to a BMW Performance intake!

Getting ahead of myself, first need to fix this pinking!!

Just out of interest. I finally had my car checked with a tuner's diagnostics machine which apparently pics up quite a bit more information than the standard diagnostics machines at most agents, and they took the car for a drive while the diagnostics was being read, so basically a live read of what was all going on. This is what they found.

Engine is not pinking, the DISA flaps are fluttering and making constant corrections but incorrectly which is causing the pinking type noise and causing the engine to run less smoothly overall. Then more worryingly, the thermostat is not working properly and forcing the engine to run too cool, so there is some over-fuelling going on, especially on colder days. The Valvetronic motor is apparently 10% out of spec, not too sure what that means, but apparently can be sorted out with software, also not sure - ECU flash?! Cylinders 1 and 5 have some strange injector / valve behaviour, so either those injectors aren't working properly or the valves are not seating correctly - but this will need further investigation.

The first thing that needs to be done is to replace the two DISA flaps and the thermostat - then run tests again to see if this solves the problems.

At least now I know I am not imagining things!

With these results took the car to the agents to see what they can find since they did have this car in for this very problem when still under motorplan - but as expected, their diagnostics picked up no faults, so clearly I am just imagining all of this and the car is perfect! Sheer driving pleasure, yeah right!

So maybe I'll fork out the money and fix this myself, or just get rid of the car (and brand) from my life!

Just looking at your plugs that you removed and the one that you showed as a replacement. It looks like the new plug is not the same as the original ones. The new one has a much longer electrod and the ceramic center is much shorter, makeing the new ones a much cooler plug.. could cause more carbonization, more PINGING.
Spelling, not my first language!!

Originally Posted by Greencar

Just looking at your plugs that you removed and the one that you showed as a replacement. It looks like the new plug is not the same as the original ones. The new one has a much longer electrod and the ceramic center is much shorter, makeing the new ones a much cooler plug.. could cause more carbonization, more PINGING.
Spelling, not my first language!!

Thanks for the reply. Well 'pinking' noise is the same as it was before I changed the spark plugs, so absolutely no difference. Plus, I have run a fuel tank of fuel with 300ml Ligui Moly Injector Cleaner to help clean out any carbon build-up - which should not be a problem with my car in the first place since I never drive short trips such that the engine does not get up to proper running temperature. Even things like starting the cold engine just to move the car outside for a wash is not done - rather go for a proper drive and then wash once cooled off a bit. Also, the OEM plugs that came out were NGK, but the ones I fitted were Bosch (both are listed on RealOEM and are specified for this motor).

Now I did take the car to a specialist tuner so that they could run the car on their diagnostics (they spend a day running thorough tests etc) and they found that the thermostat is often preventing the engine from reaching proper engine temperature and keeping the engine cooler than ideal causing possible over-fuelling - of course not as much of a problem on warmer days. Then they found that the DISA Flaps are also suspect and for whatever reason making constant adjustments which results in a fluttering noise that I am hearing. Another found is that the valvetronic motor is out of spec by around 10% (this can apparently be corrected with software - recalibrated).

Once these issues are sorted out I am going to post and reply about it on all of my various threads or threads that I have replied to since most of the time you read about problems and the various discussions but hardly ever is there a conclusion with information as to what was fixed or replaced - and then pointless asking since there is just never a reply...

Hi, I have 2005 e90 325i owned since new and I always notice a slight pinking rattle when running with windows down going past a wall or parked cars etc. Usually use 95 octane but put a tank of 98 octane in and the noise went straight away.

Well, I am still struggling with this nonsense and the specialist tuner that I went to in September has let me down big time by never returning calls, and I am simply not willing to drive out to them again, so will have to find another specialist that I can depend on.

I replaced the DISA flaps in November last year which was a fairly tricky DIY, but no real improvement, so not the DISA flaps "fluttering" as this crowd insisted. I really did not think that I would struggle to get this sorted out, and that it would take so damn long - really can't stand the car right now!

My last attempt to get this sorted out is going to be another specialist that I was recommended to and let him check fuel/air mixture, timing, O2 sensors and anything else that he suspects.

Basically, it needs to get fixed or go!! I will not spend another annoying year with this car!