V8-380-CE high temperature

[robyar]

Due to user error at the weekend, I managed to get my outdrive stuck in sand. The engine wasn't running and I got the boat free. As I ran it home, I had to keep to about 12 knots, since the temperature was rising (usually around 152F, ran home at 162F, but it did go as high as 167F). Initially, I thought I might have damaged the trim mechanism - the drive was raised when it got stuck in the sand. The sea was rough and I had my tabs deployed, but if I pulled those up the temperature went down. On the boat lift, I checked the tilt mechanism, and it is working fine.

So, my suspicion is that I have some sand / shells in the heat exchanger. I tried to pull the impellor but can't get it out (I need to buy an puller). Once I get that out and replace it, I also need to flush the system to clear out any clogs. What is the best way to do that, particularly around the outdrive? I tried flushing as usual with a hose pipe, but that doesn't appear to have fixed the problem.

Any tips appreciated!

Thanks

 

[Horigan]

Realize that you also have an oil cooler and/or power steering fluid cooler in the circuit, likely between the raw water pump and the engine coolant heat exchanger. I would back flush in sections. Remove hoses from inlet and outlet of the raw water pump and the raw water inlet and outlet(s) of the coolant heat exchanger. Backflush these sections:

1) raw water pump inlet hose back out through the drive
2) heat exchanger inlet hose back out through oil cooler heat exchangers to the raw water pump outlet hose
3) heat exchanger outlet hose forward through each exhaust manifold (ensure you flush through each manifold)
4) back flush heat exchanger

You can remove the end caps off the coolant heat exchanger to check for debris. I would also replace your impeller.

 

[robyar]

Thanks, I will give that a go!

 

[Horigan]

Try to find a schematic of the cooling system for your boat so you have a better picture of how things are routed.