A question for any BMW techies M52tu engine
Discussion
Hi,
I keep getting a pinging/pre-ignition noise from the engine on my 1999 523 more noticable under load.
Last MOT the emmissions for lambda reading were 1.029 (max allowed were 1.030) As far as I am aware thats a lean condition and that could cause the above problem.
Over the last few months I have used Shell vpower and that helps a little. Intake gaskets were done, that helped. All crank case vent pipes replaed as well as the oil seperator.
I have just replaced the 2 precat o2 sensors (made no difference).
Any other idea's?
When I repaced the o2 sensors I noticed one of the had a very light colour and the other was a tad darker in colour on the tip?
There is a small vacuum pipe that runns from the oil seperator to a fuel pressure regulator, it has no vacuum on it what so ever that I can feel by hand either at idle or when the engine is revved or returning to idle, Is this correct?
before the oil seperator was replaced there was no vaccum on it either so i assume the first oil seperator was fine even though it made some odd noises
Any idea's on whats casuing the pinging? Could it be a duff fuel injector?
I keep getting a pinging/pre-ignition noise from the engine on my 1999 523 more noticable under load.
Last MOT the emmissions for lambda reading were 1.029 (max allowed were 1.030) As far as I am aware thats a lean condition and that could cause the above problem.
Over the last few months I have used Shell vpower and that helps a little. Intake gaskets were done, that helped. All crank case vent pipes replaed as well as the oil seperator.
I have just replaced the 2 precat o2 sensors (made no difference).
Any other idea's?
When I repaced the o2 sensors I noticed one of the had a very light colour and the other was a tad darker in colour on the tip?
There is a small vacuum pipe that runns from the oil seperator to a fuel pressure regulator, it has no vacuum on it what so ever that I can feel by hand either at idle or when the engine is revved or returning to idle, Is this correct?
before the oil seperator was replaced there was no vaccum on it either so i assume the first oil seperator was fine even though it made some odd noises
Any idea's on whats casuing the pinging? Could it be a duff fuel injector?
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