MerCrusier Cooling Problems

[TomN]

I have a 5.0L MerCruisier that is over heating..Never had problems last season..Does this engine have a thermostate? If so...Could it be sticking? This is an open system....Some water appears to be flowing...Also, What is the Impeller?

 

[jeemtp_99]

Re: MerCrusier Cooling Problems

One possible problem is your impeller is bad.

 

[Boatist]

Re: MerCrusier Cooling Problems

Yes it has a thermostat and they can go bad. I do not know your exact motor and I did not see year. My boat has a pee hole on the outdrive so you know if water pump is working. <br />Thing it could be in most likley first.<br />1: If you ever run motor out of water without ear muff even for a few seconds impeller in outdirve is number one.<br />2: If you run in salt water and it is 4 to 6 years old likey exhaust manifolds or riser plugged. This can lead to total engine failure. Engine and manifolds will be hot.<br />3: Stuck thermostat. Engine will be very hot but manifolds will only be warm.<br />4: Engine water pump could be bad. Is belt tight and water pump turning.

 

[t_bird]

Re: MerCrusier Cooling Problems

I just went through the same problem, but my 302,or 5.0 ford over heated too the max about 6 months ago and my temp would fluxuate up and down,I had 2 head gaskets blown,not bad but just enough to over heat the cooling system a little.As for the impeller, if you don't know what or where it is,and you plan to work on this yourself, I would get a shop manual.That merc drive can be a pain in the butt to work on.If you have any questions about the 5.0, I have a book and would be happy to e-mail info. tbird_99@yahoo.com

 

[t_bird]

Re: MerCrusier Cooling Problems

I just went through the same problem, but my 302,or 5.0 ford over heated too the max about 6 months ago and my temp would fluxuate up and down,I had 2 head gaskets blown,not bad but just enough to over heat the cooling system a little.As for the impeller, if you don't know what or where it is,and you plan to work on this yourself, I would get a shop manual.That merc drive can be a pain in the butt to work on.If you have any questions about the 5.0, I have a book and would be happy to e-mail info. tbird11_99@yahoo.com

 

[russellackland]

Re: MerCrusier Cooling Problems

tbird11_99@yahoo.com,<br /><br /> I have the same ford 302............what temp range were your fluctuations? overheated at what temp? i havean earlier post on 21 may that has the engine info...thanks for any info