89 OMC 4.3L

[holehigh]

I have an overheating problem that I hope someone can help with. I am the original owner of an '89 Four Winns with an OMC 4.3 Cobra. It has run great for all these years with zero service needs. First time out this season and after running great again for 2+ hours, the oil pressure dropped to zero and the engine overheated. I raised the cover and oil was all down in the bildge. I assume a head gasket failed, but how can I check to be sure?? I don't want to cause more damage.

 

[Don S]

Re: 89 OMC 4.3L

The flusher that goes on the drive for water while running the engine when on land. If you are in the water, they are not necessary.

 

[Limited-Time]

Re: 89 OMC 4.3L

Don,<br />Correct me if I am wrong but there's not a gasket that would cause that kind of oil leak apart from a main seal. And if you loose oil pressure then over heat you have bigger problems than the oil leak. That said holehigh you need to follow Dons instrutcions and locate the cause of the oil leak. As for the muffs its a fixture that you hook a water hose to and attact to the out drive to feeds water to the engine allowing you to run the engine on the trailer.

 

[Don S]

Re: 89 OMC 4.3L

It has run great for all these years with zero service needs.

It had service needs, just didn't get the service.<br />Have you ever checked the impeller, the bellows, pulled the drive, checked the exhaust manifolds or anything else? You could have a lot of problems with an 89 boat and no maintenance.

 

[holehigh]

Re: 89 OMC 4.3L

the drive was pulled and gimble bearing lubricated 2 season's ago. The impeller was checked then as well. Not sure what the bellows are. If I put 3-5 quarts of oil in and start it, will the oil spew out of the gasket where it has failed (assuming that is the problem)?

 

[Don S]

Re: 89 OMC 4.3L

What you have to do, is clean all the oil up, wipe everything dry. Start the engine on muffs and see where the oil is leaking from. No other way to do it.

 

[holehigh]

Re: 89 OMC 4.3L

What do mean when you say "start the engine on muffs". I don't know what that means.<br /><br />Thanks.

 

[holehigh]

Re: 89 OMC 4.3L

Dah!! Thanks...I knew that

 

[holehigh]

Re: 89 OMC 4.3L

I am not a mechanic, so forgive my ignorance....what is the difference between a main seal and a gasket? And how best can I determine where the leak is coming from? Just put oil in the motor and start it and watch where it comes out?

 

[Don S]

Re: 89 OMC 4.3L

Main seals refers to the seals that go around the ends of the crankshaft. They are rubber and round with a steel outside edge and a rubber lip that rides on a machined smooth portion of the crank.<br />A gasket is usually considered to be made out of paper and is between two pieces of metal to prevent leaks. Orings are an exception to the rule and act like a paper gasket in that instance.<br /><br />While it could be a main seal, I doubt it is. I suspect you will find a rusted through pin hole in either the timing chain cover or oil pan.

 

[holehigh]

Re: 89 OMC 4.3L

Thanks for your insight Don. I will have to take the back bench seat out to get a good head-on look at the motor, but I guess I will do that and put more oil in and see if I can determine where the leak is coming from. I assume it will not hurt the motor any adt'l amount at this point to put more oil in and run it?