Engine knock,Need Mechanic.

J

jmas

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Apr 22, 2001
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Came in from fishing trip offshore yesterday. Both engines ran great.(1995 454,s Fresh water cooled). Do not burn oil, Coolant is always full. Started engines today and hear a knocking sound from Starbord engine. Sounds like more than a lifter problem. No noise heard at idle but starts at 1200/1500 RPM.
Any sugestion on good marine engine mechanic, Pompano ,Fort Lauderdale area?
 
Check oil level anyway. knocking at start-up, hopefully, is oil drain back. How long was the engine running when the knock was heard.

Unfortunately, spun crank/main bearing or rod bearing will require complete rebuild.
 
rule out the simple stuff with a hose as a stethoscope listen at front and rear. If I/O see if it is related to turning the steering.
 
Charlie, I am expecting the worst.

Bruce, They are Inboards. Tried the Stethescope first thing. Sounds like Connecting Rod or wrist pin Knock.
Will get an opinion from a Mechanic but I am expecting to take engine out,Maybe replace both.
1200 hours and always maintained.
I have to get over the SHOCK.:(
 
Had a mechanic check engine. He is sure noise is caused by faulty Harmonic balancer and thinks it can be replaced with engine in boat. If he is right, it is good news.
Hoping no other damage caused.
 
Big blocks are externally balanced like my 400 small block, which means the flywheel and harmonic balancer are weighted to off-set the internal rotating assembly. The only things that can happen to the balancer is slipping of the outer ring or shearing the key-way. Either can cause damage to all the internal bearings if allowed to continue running like that.

On the other hand, it's a very simple fix.
 
Now that's a great lesson! Thanks for the continuing education....
 
That's why I asked to listen up front. Surprised you didn't hear it.
 
Balancers sound to me more like clacking while rods and mains are more muffled from being inside.
 
I have been getting a squeeling noise at startup recently,like a loose belt slipping on a pully but all belts were tight. Should have alerted to check the HB.
Is thread differant on bolt on LH/RH rotation engine? (LH thd.-RH thd.)?
 
Turns out Harmonic Bal. is OK. 3 mechanics confer Bearing knock. Engine will have to come out.
1200 Hrs. on both engines, maybe both should be replaced?
 
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