loud tapping noise from 3.0l mercruiser

[spion]

I own a 93 rinker 180 captiva with a 3.0l mercruiser,problem that has happened several times now is a loud tapping noise coming from the engine at about 4000 rpm 3/4 throttle ,oil pressure is at 40 psi,I shut down the motor ,wait a minute and restart,everything is fine,start off and the noise will come back only sometimes,can,t pinpiont where it is coming from.motor is trimed at 1/2 on my trim meter,any ideas of what this is or where it is coming from?? thank-you for any help in this matter.

 

[dodge1971340]

Re: loud tapping noise from 3.0l mercruiser

Hi Spion!! sounds like a lifter is bad, there problable hydrolic losing pumpup at higher rpm's but not 100% without hearing it. does it sound like it at the top of the motor? hope i helped and God Bless!! Dodge

 

[Don S]

Re: loud tapping noise from 3.0l mercruiser

Check your oil level. If it's overfull, the crank will hit the oil and aireate it and cause the lifters to collaps.

 

[spion]

Re: loud tapping noise from 3.0l mercruiser

thanks don my oil level is a little over full mark,will drain it down a bit and see if that was the problem,thank you all for your replies.

 

[Mile-High Mariner]

Re: loud tapping noise from 3.0l mercruiser

Spion - make sure you come back and share what you found, as well as what corrected your noise. As Don indicated, it may be one or more collapsed lifters due to oil starvation (overfilling is as potentially damaging as underfilling for the reason Don mentioned), or that same lack of lubricant may have initiated something more serious in the crankcase, like bearing failure. Hopefully, it's the former, and drawing off some oil will allow the lifters to pump back up and you'll be back out on the lake in no time.

 

[Mile-High Mariner]

Re: loud tapping noise from 3.0l mercruiser

Sorry, double post (ISP error).