volvo inboard/outboard 4 cyl?

[slew]

at idle it runs hot, give it the gas and it cools down to normal temp. after it cools down after running hard you can now idle and it stays cool, just the first start if you set and isle is when it runs hot

[fireplug]

Sounds like a stuck thermostat

[jcr286]

have you replaced the impeller recently?

May not be the main problem, but it's always good to check it when having temperature issues.

[SwampMan]

Impeller needs replacing.

[Bully]

Volvo's do not have an impeller in the lower unit like a Mercruiser. It is up at the engine. The cooling system is draining down when it is not in the water and it is not priming back up until you rev the engine. Next time you put it in the water, rev it up in neutral as soon as you get it in the water. Then bring it back down to an idle and let is sit there for a little while. I will bet it does not get hot.

[southernvaughan]

[SwampMan]

[Bully]

[deltadukman]

[miket]

Don't know about all Volvo's, but any sterndrive I have ever seen that does not have a water pump in the outdrive has a belt driven raw water pump on the engine . This one has a rubber impeller and draws the water from the lake to supply the engine's cooling system. Most impellers are supposed to be replaced 1-3 years depending on what style they are. There is also the automotive type pump on front of the engine to aid in circulating the water through the engine. If this is a later model with a GM four cylinder it is set up like this.

[southernvaughan]

[slew]

impeller and thermostate also sticking. thanks guys for the help