Pinging

[jj7]

dear all, i am proud to be a part of this forum, and this is my first posting.
my name is jafar,currently living in malaysia, i imported a 525i 94 from japan, its my second BMW,the first i had was a 520i 91.
the 525i got a long history,but won`t depress with that,at the moment there is the pinging for a year now,lately the car is acting really strange:

1- pinging with gear up-shifting, rpm below 3k
2- hesitation on take off
3- sometimes no response/slow response when gas applied
4- idle most of the time low

more to that,on the modic3 no fault codes,all sensors are within the specs, had the ecu repaired in the US,new catalytic, replaced 2 ignition wires which used to give less than 12v with ignition switch on,cleaned all the ground points as possible, battery flow is optimum,fuel regulator 3bar,new fuel filter, new ignition coils and sparks.cleaned the throttle body.

the car is great and a real bmw when warming up,once the gauge in the middle all those symptoms show up.the only ideas i have is to have the chambers checked for carbon build up and injectors tested and cleaned.
the car is auto...
thanks all

[RobPatt]

injector cleaning (BG44K, couple of cans and tanks...) and running the daylights out of it cross country for a while? I've got a '93 525ia (auto) and it too pings when up shifting below 3K. You'll see many of our cars w/the M50TUs seem to do this... but I don't have the hesitation problem. You've Clogged air filter perhaps? Vaccuum leak on intake somewhere? Good luck, I'd focus on the hesitation as long as the pinging isn't too bad.
, Rob.

dear all, i am proud to be a part of this forum, and this is my first
posting.
my name is jafar,currently living in malaysia, i imported a 525i 94 from japan, its my second BMW,the first i had was a 520i 91.
the 525i got a long history,but won`t depress with that,at the moment there is the pinging for a year now,lately the car is acting really strange:

1- pinging with gear up-shifting, rpm below 3k
2- hesitation on take off
3- sometimes no response/slow response when gas applied
4- idle most of the time low

more to that,on the modic3 no fault codes,all sensors are within the specs, had the ecu repaired in the US,new catalytic, replaced 2 ignition wires which used to give less than 12v with ignition switch on,cleaned all the ground points as possible, battery flow is optimum,fuel regulator 3bar,new fuel filter, new ignition coils and sparks.cleaned the throttle body.

the car is great and a real bmw when warming up,once the gauge in the middle all those symptoms show up.the only ideas i have is to have the chambers checked for carbon build up and injectors tested and cleaned.
the car is auto...
thanks all

[jj7]

injector cleaning (BG44K, couple of cans and tanks...) and running the daylights out of it cross country for a while? I've got a '93 525ia (auto) and it too pings when up shifting below 3K. You'll see many of our cars w/the M50TUs seem to do this... but I don't have the hesitation problem. You've Clogged air filter perhaps? Vaccuum leak on intake somewhere? Good luck, I'd focus on the hesitation as long as the pinging isn't too bad.
, Rob.

Rob,thanx for the reply,i forgot to mention the car got 70k Miles,as for the gas i only use the shell V-power and its 97.The pinging was hardly noticed in the begining,but now it is continious thing even when somtimes on high speed i can hear it,btw i checked the air filter it was clean, as for vaccum i am looking for any articles on that.stry the bmw work shop claim that the modic can detect any vaccum leaks or at least it can tell if there is any possible leaks,not too sure how true this is..
the mechanic suggested to check on the vanos,he mentioned a kit was available to service it and to adjust the timing, but after that he said that if timing was wrong the modic will find it,so i was left in doubt.
that said, i sometimes wonder if a sensor doesn`t give a fault code,could it faulty? in terms if it is checked manually according the specs???

[DanQ]

the car is great and a real bmw when warming up,once the gauge in the middle all those symptoms show up.the only ideas i have is to have the chambers checked for carbon build up and injectors tested and cleaned.
the car is auto...
thanks all

This statement leads me to believe that there is a temperature sensor not telling the computer that it is at operating temperature. I am not sure where the sensors are or how to manually check them but that is where I would start.

[jj7]

This statement leads me to believe that there is a temperature sensor not telling the computer that it is at operating temperature. I am not sure where the sensors are or how to manually check them but that is where I would start.

Dan,appreciate the input, what is going on here that when the engine warms up lets say after few minutes time, the pinging starts but it doesn`t do that before the gauge is in the middle...i sometimes suspect something mechanical inside the engine,after all components arm up some expand others don`t,this is a wild guess, or the lubrication system got some flows inside the engine that causes the oil not to function properly,what puzzles me is that no sensor is giving any fault code

[ryan roopnarine]

if bill was here, he'd tell you that the likely reason that it doesn't ping when the temp isn't at operating temperature is because the car is running in open loop, ie, the oxygen sensor isn't being used yet. when the car is cold (any oxygen sensor car)....the computer runs things rich until it is sure that things are OK before optimizing fuel consumption. i'd start checking for vacuum leaks and maybe get yer injectors cleaned/run something to start cleaning up carbon. i'm beginning to believe that all m50s of our representative vintage get quite a bit of carbon, was checking in there about 2 weeks ago, there's a hell of a lot of carbon down in my cylinders, and a lot of m50 people report the same 22-2800 rpm ping problem.

Dan,appreciate the input, what is going on here that when the engine warms up lets say after few minutes time, the pinging starts but it doesn`t do that before the gauge is in the middle...i sometimes suspect something mechanical inside the engine,after all components arm up some expand others don`t,this is a wild guess, or the lubrication system got some flows inside the engine that causes the oil not to function properly,what puzzles me is that no sensor is giving any fault code

[RobPatt]

...pull a spark plug and shine a light? I lit it up once while changing plugs and couldn't believe what I saw.. top of the piston looked like the plastic coating in the intake manifold.... blew me away..... by the way, know a 'net reference on how to do a compression &/or leakdown test? thx, Rob.

if bill was here, he'd tell you that the likely reason that it doesn't ping when the temp isn't at operating temperature is because the car is running in open loop, ie, the oxygen sensor isn't being used yet. when the car is cold (any oxygen sensor car)....the computer runs things rich until it is sure that things are OK before optimizing fuel consumption. i'd start checking for vacuum leaks and maybe get yer injectors cleaned/run something to start cleaning up carbon. i'm beginning to believe that all m50s of our representative vintage get quite a bit of carbon, was checking in there about 2 weeks ago, there's a hell of a lot of carbon down in my cylinders, and a lot of m50 people report the same 22-2800 rpm ping problem.

[ryan roopnarine]

here's a pic of me checking for carbon buildup



just kidding......i did the flashlight deal when i did the saturn piston soak, that's how i saw it. it was unbelievable how much carbon was flying out of the spark plug holes when i finished the soak step and cranked the starter, seemed like a neverending amount. if i get some free time during christmas and access to an aircompressor i might try it again (until clean to my satisfaction). here's a page with the leakdown instructions. do you have a problem that makes you want to do a leakdown?

http://www.xs11.com/tips/misc/misc3.shtml

[jj7]

here's a pic of me checking for carbon buildup



just kidding......i did the flashlight deal when i did the saturn piston soak, that's how i saw it. it was unbelievable how much carbon was flying out of the spark plug holes when i finished the soak step and cranked the starter, seemed like a neverending amount. if i get some free time during christmas and access to an aircompressor i might try it again (until clean to my satisfaction). here's a page with the leakdown instructions. do you have a problem that makes you want to do a leakdown?

http://www.xs11.com/tips/misc/misc3.shtml

Ryan nice comments and straight to the problem, the other day i did the decarbonising through the intake, didn`t do much difference..i still belive that there is carbon deposit in the chambers that after the engine its hot and the spots get hot as well,they start doing their wonders...since i am looking at fuel,electric and air the first two i ruled them out with testing, as for the air issue i want to check every possible air leak.
one important thing was mentioned is that the m50`s got this pinging problem, this forum contains so many methods to overcome it, i am sure if all those methods are gathered as a group, any friend with the same problem can find easily(just a thought), if a list is made ready, starting from the cheap procedure to the most expensive..we put mechanics out of business..
(no offence)...
I tried to find a place which uses a berescope to avoid the cylinder head disassembly, but will try using a strong flash light through the spark plug holes

[jj7]

Ryan nice comments and straight to the problem, the other day i did the decarbonising through the intake, didn`t do much difference..i still belive that there is carbon deposit in the chambers that after the engine its hot and the spots get hot as well,they start doing their wonders...since i am looking at fuel,electric and air the first two i ruled them out with testing, as for the air issue i want to check every possible air leak.
one important thing was mentioned is that the m50`s got this pinging problem, this forum contains so many methods to overcome it, i am sure if all those methods are gathered as a group, any friend with the same problem can find easily(just a thought), if a list is made ready, starting from the cheap procedure to the most expensive..we put mechanics out of business..
(no offence)...
I tried to find a place which uses a berescope to avoid the cylinder head disassembly, but will try using a strong flash light through the spark plug holes

BTW, ryan do you seem to have any article or reference regarding the soaking procedure?? i appreciate that