ZR6 OVER HEATING, SUCKED UP SAND

[guyhawk]

I would really appreciate some help with this, to cut a long story short my 2 year old son drove daddy's pride and joy up the beach filling the water intake pipe and strainer with sand which i did'nt notice until the over heat alarm went off so i emptyed the strainer of sand, ran the engine for a few seconds then emptyed it again (did this several times until clear) but ever time i use the boat the alarm goes off after approx 10 mins or so at 24mph with it going off sooner the faster i go then if i slow down to idle the engine cools down to about 155f (alarm sounds at 198f). I have changed the impellor even though the old one looked o.k, I have taken each end of the heat exchanger off and this seems clear and have taken the drain bolt out of each exhaust manifold where i did find a small amount of rust and sandy much but only about half an egg cups worth and its still over heating does any one have any ideas, could it be the thermostate even though its closed cooled, could over heating cause damage to stat, oil/water levels are fine and clean and the rubber seal is still in the strainer so i don't thinck its sucking in air, its a 2008 zr6 in a 220 and my dealer is over 250 miles away so would really like to sort this out myself as i think it most be a blockage some where. i have also pulled most of the pipes off and have checked the in line oil cooler, any suggestions would be great, Thanks

[Rick]

RE: ZR6 OVER HEATING, SUCKED UP SAND

If its close cooled then the thermostat only works within the closed part. I would suspect a small air leak in the strainer or posssibly in the hoses. I would also wonder if the raw water pump has been scoured and the impellar isn't pumping a sufficient amount of water. Finally I would look for a blockage in the manifolds. Can you run it with a fake-a lake to see if water is flowing through the manifolds. Usually the faster you go the more water pumped. So it sounds like the faster you go the less water. That would indicate an air leak to me Good luck.

[hdultra]

RE: ZR6 OVER HEATING, SUCKED UP SAND

Also double check your orings on the impellar as well. With that much sand I agree with checking the impellar housing.

[guyhawk]

RE: ZR6 OVER HEATING, SUCKED UP SAND

have tried all that you've suggested but still over heating, the boat is fitted with a fresh water flush so have checked manifolds and are all o.k, impellor housing is fine to, and theres no air leaks any more suggestions as Ive gone through pretty much the hole cooling system and all seems fine

[HS]

RE: ZR6 OVER HEATING, SUCKED UP SAND

check the fresh water flush cap; if it is not tight, it will cause overheating.

[guyhawk]

RE: ZR6 OVER HEATING, SUCKED UP SAND

it was a small amount of sand in the tee fitting of the fresh water flush causing the spring and slide to stick in the half closed position, cleaned it out and know all working fine, thanks to nawteak

[WakeSlayer]

RE: ZR6 OVER HEATING, SUCKED UP SAND

How in the world does a 2 year old drive a $70k boat up onto the beach?

[Red57Bird]

Re: RE: ZR6 OVER HEATING, SUCKED UP SAND

How in the world does a 2 year old drive a $70k boat up onto the beach?

I was wondering the same thing. My 2 year old nephew "drove" my boat this past weekend, but he was on my lap and he barely had his hands on the wheel.

[guyhawk]

RE: Re: RE: ZR6 OVER HEATING, SUCKED UP SAND

The beach is on a tidal river with a 6 knot current flowing past so when you put the bow onto the beach you have to leave in gear on tick over or the stern swings on to the beach, must remember not to stand up and open windscreen for the wife next time!!!!!!!!

[AirTool]

RE: Re: RE: ZR6 OVER HEATING, SUCKED UP SAND

Maybe set your Perfect Pass in rpm mode at some low value to prevent throttling past set point.