1983 Mecruiser inline 470 overheating

[ship-wrecked]

I purchased this boat last year and I have had the<br />overheat problem ever since that day. Only under<br />load. We have changed the impeller in the lower unit no change to problem.We now have water coming<br />out of a weep hole in the closed water impeller<br />cover. This motor does not have a water pump but<br />a water impeller. what is causing the leak of anti<br />freeze?

 

[Walt T]

Re: 1983 Mecruiser inline 470 overheating

Plugged heat exchanger. Circ pump is leaking too.

 

[johnkc]

Re: 1983 Mecruiser inline 470 overheating

the seals on the end of the camshaft are leaking,you can use repair sleeves to fix the grooves in the end of the camshaft where the seals ride. Walt's probably right about the heat exchanger being plugged.and if it is a 3" heat exchanger you may want to locate a 4" as the 3"s were marginal in the first place.also remember that if this engine still has the original charging system the voltage regulater is water cooled and will get too hot if you have a low flow of water from the drive.

 

[Walt T]

Re: 1983 Mecruiser inline 470 overheating

I really need to read posts more carefully. Johns right about the cam seals.

 

[rodbolt]

Re: 1983 Mecruiser inline 470 overheating

hello<br /> also check the exhaust riser. if its partially clogged it wont allow enough water to escape and keep the heat exchanger cool I have a brand new one here that was bolted on and never used. but now I have no use for it.<br /> good luck and keep posting]