1995 Mercruiser 3.0L - Keep busting push rods

madmarino

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Sep 28, 2009
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2
Hello,

I'll start off by saying I am relaying information. Not being a mechanic its entirely possible I am messing up terminology. I'll try to keep my post accurate and edited for content.

Our issue is that we seem to be rebuilding our Mercruiser regularly. The problem is always the same, we use the boat for a handful of times over the summer and at the end of the season the engine dies in a similar fashion.

The problem always turns out to be bent rods and/or broken Rockers/Rollers.

As this is the 3rd time around I'm starting to think that we are doing something wrong or not doing something right.

Are there any known issues with this engine in regards to the symptoms I described?


One note that I would like to mention as well is that we typically try and troll with this engine as slow as it will go. The engine nearly stalls while are fishing. Maybe this stress is part of our issue?

Also what causes the rods or lifters to get bent? Are they seizing?


I'll be glad to relay more detail if required. Thanks for any help that you can muster.

A
 

IES99

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Jun 3, 2008
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271
Re: 1995 Mercruiser 3.0L - Keep busting push rods

Are you sure that it is not overheating?
 

Bondo

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Re: 1995 Mercruiser 3.0L - Keep busting push rods

Are there any known issues with this engine in regards to the symptoms I described?
Nope,...
As this is the 3rd time around I'm starting to think that we are doing something wrong or not doing something right.
Ayuh,... I have to Agree with that...

If the motor is getting the valves Wet with water, they could be rusting between uses...
Low idle is Not the problem...
 

Apollo75

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Sep 2, 2009
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Re: 1995 Mercruiser 3.0L - Keep busting push rods

If the motor is getting the valves Wet with water, they could be rusting between uses...
Low idle is Not the problem...

To bend pushrods and break rockers takes considerable pressure ---- like hitting the piston at high rpms ---- or like Bond-o said, valve stems rusting in guides. I would check the exhaust for water intrusion and if nothing is found install bronze valve guides and stainless steel valves.

I have had the same problem on my old 1937 yacht / major money pit with 318 chrysler B blocks that I did not use nearly enough and the valves rusted. :mad:

OFM
 
Last edited:

madmarino

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Sep 28, 2009
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Re: 1995 Mercruiser 3.0L - Keep busting push rods

Thanks guys, I'll pass it along and try to get more detail.
 
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