new engine running hot

[bwrag]

My mechanic called me this morining and said he got my new engine in but it is running hot. I recently replaced the 5.7 black scorpion engine in my boat because of cracked block. the impeller is new and the boat was running cool previously to changing the engine. Any ideas would help.

Thanks

[da.bell]

What temp is it running at?

[bwrag]

got over 200 then he cut it off.

[chpthril]

I'd say that the running hot may have been the root cause of the cracked block.

Is the impeller housing new and or in good shape?

new thermostat?

new circulation pump or was the old swapped over to the new block?

The entire raw water system needs to be inspected from the scoop to the engine for any kind of restriction.

Incorrect timing or excessively lean air/fuel mixture

blocked or collapsed exhaust manifolds.

[bwrag]

is there a way to reverse the flow of water maybe to clean the system out

[chpthril]

is there a way to reverse the flow of water maybe to clean the system out

Back-flush with a garden hose.

[bwrag]

How would I go about doing this?

[chpthril]

How would I go about doing this?

Pull the hose off the inlet (bottom hose) of the raw water housing and shove the hose in and turn the water on full blast. I would maybe put a catch pan under the scoop to catch whatever may come out.

[gman]

Did they install the proper thermostat? Is it backwards (upside down). I was in a hurry and did that on a car one time!!!

[bwrag]

the mechanic called this morning and said it just started working I will run it out of the lake when i get it home to make sure it expelling water out the exahust. But my main concern when the impeller was changed at the first of the year the mechanic said 3 of the fins were missing and he couldnt find them. Any Ideas?

[bwrag]

Also thanks for all the input i appreciate it.

[chpthril]

the mechanic called this morning and said it just started working I will run it out of the lake when i get it home to make sure it expelling water out the exhaust. But my main concern when the impeller was changed at the first of the year the mechanic said 3 of the fins were missing and he couldn't find them. Any Ideas?

Couple thoughts: a piece of impeller may have blocked the thermo or water passage, but I would bet it would be more likely to wedge in the thermostat and cause it to stay open, resulting in the engine not reaching operating temp V's running hot. More then likely, there was an air pocket under the thermostat, which would prevent it from reaching the correct temp and opening.

[dogbert]

Couple thoughts: a piece of impeller may have blocked the thermo or water passage, but I would bet it would be more likely to wedge in the thermostat and cause it to stay open, resulting in the engine not reaching operating temp V's running hot. More then likely, there was an air pocket under the thermostat, which would prevent it from reaching the correct temp and opening.

My bet would be on blockage as well. The best thing to do is run water in reverse of the normal water flow when you shred your impeller like that.

[bwrag]

Is there no trap somewhere?

[dogbert]

Nope. It just ends up somewhere in the engine. That's why it's so important to get it back out. My guess is that it finally worked it's way through. Glad it's fixed.