Cricket like sound at light throttle

M

maharadja

Member
Hi and greetings from Sweden!
This forum has alot more members then our swedish forum so i hope i will have more luck here!

My z4 3.0i 2003 convertible makes a very low rattling/cricket like sound when i gently push on the throttle. It is clearest on first to third gear. I can not locate the sound, its from the front thats it. And it is just if i push gently on the throttle, but that might be because if i push more the engine sound just get louder than this rattle sound. This bugs me but often my buddies can not hear it so i might just be crazy or something...
Do you have any ideas what might make this sound?
 
Hi! I have replaced the disa valve just recently!
My car has just done 31 000 miles, if the converter has done the job right (5 000 kilometers).
 
You need to get someone to press the accelerator pedal whilst you listen at the engine for the noise and try to isolate where it is coming from.

I had similar noise from my 2004 3.0i and eventually found out it was the mechanical tensioner unit. Where it is mounted on the oil filter housing warps and allows the tensioner to move on its 2 fixings causing this chirp at 800-950 rpm. The hydraulic tensioner which I replaced it with has 3 fixings and holds the tensioner solid.
 
Ok! Been some time since i last put some effort on this but i think i only can hear this sound when i drive with a gear in. So while standing still and pressing on the throttle i can not hear it.
 
When I had my 2004 3.0, it would pink under load only. So if you drive downhill and feather the accelerator, do you still hear it? If you do, then it is not pinking.
 
maharadja said:
Sorry but what is pinking? :oops:
Click to expand...

Pinking is a sound caused by less than perfect combustion conditions/engine settings, it's usually a light metallic sound.
Rob
 
maharadja said:
Hi! I have replaced the disa valve just recently!
My car has just done 31 000 miles, if the converter has done the job right (5 000 kilometers).
Click to expand...

You got one extra 0 in there. 5000km is about 3100 miles. :)
 
I had something similar to this on my last car (not a BMW) and it turned out to be a tensioner pulley.
They replaced it and the noise went away.
Could be a similar thing (I'm no mechanic so not even sure if this would apply to z4 engine???? But and idea to check).
Rich.
 
Hi, I don't know if you have managed to source what's causing the issue. If not I had a similar thing with my Z, it was a cricket sort of sound, after changing pulley and few other things which didn't work, it ended up being the exhaust studs had rotted through and the gasket had a very slight leak which gave the noise when the engine was under any load. If you can get under the car you will be able to check this where the exhaust meets the top of the manifold. Hopefully it's just this as it's a cheap fix :thumbsup:
 
No worries, you will need someone to rev it for you whilst you listen under there. The noise would disappear when we jacked the exhaust up very slightly, as it closed the gap. Good luck :thumbsup:
 
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