Brunik

I have a 550i M Sport with 85000 Km on the clock. I notice that around 3000-3500 RPM (under no load) there is a rattle in the engine which sounds like valve timing system noise (possibly). After say 15km from cold it seems to go away. Does anyone know what this may be, or if it is of concern?. the car performs excellent otherwise, I'm just concerned there may be something terminal creeping onto the engine.

response_surface

my 545 does exactly the same thing. i use mobil 0w-40.... when the oil is new, less than 1k miles, it does not do it at all. i'm going to change my oil in a week or so and am planning to use mobil 5-50 instead. i think the higher visc oil will help. the m5 uses 10-60, so how could a 5-50 hurt my v8? it never gets cold where i live, i don't need that low visc oil.

Brunik

Thanks for your reply, I an running Mobil 1 5-30 as recommended by BMW service dept. I have done about 100km since oil changed and just noticed rattle now. So maybe it is the oil selection. I line in New Zealand temp range between 0 to 25 celcius.

turboawd

i get the same noise when free-reving the engine. i think it has to do with no load, and the adjustable valves. normal to me.

response_surface

ok, i changed my oil this weekend. i used the mobil 5w-50. the noise is MUCH less than it was, but still there. i think it must be normal. going to drive the car until it breaks. has 50k on it now, hope it lasts another 50k.