Volvo 7.4L IO overheating

deckswabber

Cadet
Joined
Jun 30, 2004
Messages
13
Hi, I am a newbie, so please bear with me if I'm a bit ignorant. My family recently took possesion of a 1994 Rogue Cruisers with dual 1994 Volvo Penta 7.4L IOs. <br /> On the way home (on the Sacramento Delta) we (myself and some other newbies) put it in some mud, and both IOs sucked up considerable amounts of mud, to the point where it was hot enough to smoke. The thermal protection kicked in and the motors seem fine (they start and run smootly).<br /> We have subsequently had it cleaned and both impellers replaced (the starboard impeller was finless when it was replaced :( ). Even after a good cleaning and impeller replacement, both motors overheat at idle, and there doesn't appear to be any water going into the motor from the IO. <br /><br />So, my questions are:<br />1) Any idea what could be wrong?<br />2) Is it possible that impeller pieces or mud got sucked into the block(which would probably mean that we need to have the heads removed to have it cleaned)?<br />3) Is it possible that there is a thermostat or screen that we have missed that need to be replaced?<br />4) Anything else?<br />Thanks (alot)!
 

Dunaruna

Admiral
Joined
May 2, 2003
Messages
6,027
Re: Volvo 7.4L IO overheating

Hi littlebuddy,<br /><br />Are your motors fresh or raw water cooled?<br /><br />Aldo
 

deckswabber

Cadet
Joined
Jun 30, 2004
Messages
13
Re: Volvo 7.4L IO overheating

Hi,<br /> They motors are raw water cooled. We were able to detach the IOs and get water to flow through the block, so we're pretty sure the block is ok. We will check the oil coolers We think the IOs are probably just clogged (phew) because they don't seem to be pusing any water into the motors. As far was we can tell, the boat is going to have to come out of the water to get the IOs cleaned. True?<br />Thanks again!
 
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