Author Topic: Rattling/metallic type tapping - possibly pinging (Read 2852 times)

nicknikolovski · « **on:** February 20, 2008, 02:09:52 AM »

Hi, i own a 93 318is coupe - m42 motor of course.

I recently replaced my entire timing chain set-up with all new parts. Before this i had a rattling/metallic tapping type of noise coming from the engine and it failed to go away after chain replacement.

The noise is only heard from inside the car and when accelerating or under heavy load. I am thinking that the engine is pinging and that the knock sensors could be faulty. However no engine light has ever come on.

Could knock sensors also cause the engine to misfire every now and then?

Even though the valve timing is correct could the ignition timing be to advanced due to the knock sensors failing?

Can I test these at all and how difficult are they to replace?

Any help would be appreciated.

Also has anyone else experienced this?

demon510 · « **Reply #1 on:** February 20, 2008, 08:37:51 AM »

Check for an exhaust leak, retorque the exhaust manifold and the downpipe.

nicknikolovski · « **Reply #2 on:** February 21, 2008, 03:02:16 AM »

thanks for the info, next chance i get I'll check it out.

Choking Hazard · « **Reply #3 on:** February 21, 2008, 07:14:36 AM »

try a lighter viscosity oil....

nicknikolovski · « **Reply #4 on:** February 22, 2008, 03:06:02 AM »

Hi chocking hazard, i'm using 5W30 Mobil 1 Fully Synthetic. I used to use Castrol GTX3
10W40. Maybe I should go back to thicker oil, my car seemed to run better then. I'm gonna check my exhaust manifold nuts as soon as I get a chance. I think Bentley listed the torque value as 11ft-lb (15Nm).

rusty · « **Reply #5 on:** February 25, 2008, 11:08:17 AM »

also due a top engine clean carbon build up could cause this problem is it worse after the vehicle is warmed up? a knock sensor shouldnt cause a missfire but poor ignition will could also be part of your other problem. make sure your coils plugs and wires are good.