Engine overheating - Impeller is fine

[bg2pres]

Has anyone had engine overheating problems in a 05 Monsoon 340 when there was not blockage, impeller is not damaged and water flow is normal? I am not talking about a missed guided alarm or temp gage. This is a header smokin overheat...

Happened to me this weekend. It is now in the shop and will not start. Temp alarmed at 207 and jumped to 217 quickly and I shut it down.

Now it won't turn over....

Very weird. Hopefully not a replacement engine as a solution...

JB

[jgouveia3]

bad thermostat, maybe.

[bg2pres]

Well, I thought the same until the flow was fine....

Does a water cooled boat have a thermostat?

If so, why and where is it located?

bad thermostat, maybe.

[RTS]

If your thermostat is malfunctioning, you'll have the same amount of water flow into the lake pick up and out of the exhaust pipes...your impeller dictates this. But the problem with the bad thermostat would be that the water is going "the wrong way" internally, and would cause you to overheat.

[jgouveia3]

yup. still needs a thermostat to control flow of cooler water to cool the internals of the engine. should be located at the top of the block, front of the engine (could be backward in your backward engine :-) )

[JasonK]

How do you know if the water flow is normal? Was that before you put it in the water? If it won't start now, I think it would be hard to confirm.

Make sure the raw water pump hoses aren't installed wrong. ? maybe?

[BlastRlxi]

The shut off valve on the raw water intake near the thru-hull fitting isn't closed, is it?

[Brad B]

I'm confused too - how do you know that flow was normal?

[bg2pres]

Well, I guess I didn't. If the thermostat stuck closed and it can bypass the heads, then I guess it was the thermostat...

Dealership called and I had water in 6 of the 8 cylinders and the engine was hydrolocked...

New Indmar monsoon is on it's way...

Heads cracked and engine didn't shut it down....

REMINDER... If you overheat, don't rely on the computer to protect you...

Warranteed, thank god.