OMC 4.3 with strange rattling noise.

LassePelle

Seaman Apprentice
Joined
Sep 4, 2009
Messages
34
Hi. I have this noise in front of my engine, and it sounds like it is from the timing chain. I have never heard this sound before, but it showed up after oil change. The oilpreassure also seems to be too high. It goes up to 80psi as soon as i rev the engine up a little bit.
When it is hot it drops alittle, but is still around 50-70 psi. I have used Pennzoil heavy duty 15w40 marine engine oil.

The engine is from 1988 and the last owner said it was rebuildt approx 5 years ago. This of course i cannot be sure about.
Hope someone have any idea what this can be.
I have added a video where you can hear the sound :)

 

Howard Sterndrive

Rear Admiral
Joined
Nov 5, 2008
Messages
4,603
Re: OMC 4.3 with strange rattling noise.

check the pressure with a mechanical gauge.
Have you poured additives in with the oil by chance?

I can't hear anything but the exhaust.
 

LassePelle

Seaman Apprentice
Joined
Sep 4, 2009
Messages
34
Re: OMC 4.3 with strange rattling noise.

Hi. I will test with a gauge asap :) There is only oil in the engine, nothing else. The sound i am speaking about is heard when i film in front of the engine. Right when i lower the cam in front u can hear a kind og rattling, like a chain against metal or something. The sound is easiest to hear at low rpm and after 2500 i cannot hear anything.
 
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