Overheating 03' 22V

[BillyZ]

I have an 03' 22V that is overheating. The impeller looked fine but I replaced it anyway. I left the hose off that goes to the water pump from the transmission cooler and when I turn the fake a lake on water isn't flowing through. Should there be water there or does the pump pull it in?

Thanks

Bill

[chpthril]

The raw water pump will suck on the inlet side and push on the outlet side, so not sure which hose you loft off, so not clear on which direction the water would be going from your perspective. Also, need to clarify raw water pump or circulation pump.

[BillyZ]

Looking from the back of the boat the pick is on the right side of boat. From there it runs to the inlet of the transmission cooler. On the opposite
side of transmission cooler is the out let that goes to the water pump. I have connected a hose to that side and water will flow in the backwards direction but when I put water through in the correct direction nothing comes out. Is there a check valve in the transmission cooler that may be malfunctioning?

Thanks

The raw water pump will suck on the inlet side and push on the outlet side, so not sure which hose you loft off, so not clear on which direction the water would be going from your perspective. Also, need to clarify raw water pump or circulation pump.

[chpthril]

So water only only flows one way through the trans cooler? And you are sure this is the trans cooler and not the v-drive? No check valve, but likely full of exploded impeller and other crap.

[freeheel4life]

Looking from the back of the boat the pick is on the right side of boat. From there it runs to the inlet of the transmission cooler. On the opposite
side of transmission cooler is the out let that goes to the water pump. I have connected a hose to that side and water will flow in the backwards direction but when I put water through in the correct direction nothing comes out. Is there a check valve in the transmission cooler that may be malfunctioning?

Thanks

If it's a merc 350 mag mpi than you are off on you flow. Find the water pump down low on the engine. Port side, belt driven pump. The harder walled tube is the suction line. The softer rubber is the the outlet or pressure side (it is also larger in diameter than the suction line). remove that line from the trans cooler and look in. grass, and other debris can plug up the cooler.

[BillyZ]

Its all clear to the pump and past it to the outflow hose. Impeller is brand new and is working. I am headed out to start pulling hoses to see if I can find a clog somewhere. Is there a common place where crap gets stuck that I can check.

Thanks

Bill

[chpthril]

if it is a Merc, then the trans cooler, which is often downstream of the raw water pump on the Mercs.

[BillyZ]

Just ran it for 10 - 15 minutes and it got to 175 and stayed for quite a while before heading up and I turned it off. What is weird is that the thermostat housing where the temp pick is mounted is the only thing hot. I am able to rest my hand most everywhere else. I tested the thermostat and it open at 160. I am way over my head on this and would happily take it to a mechanic but the soonest I can get in is 7/28. All help is greatly appreciated.

Thanks

Bill

if it is a Merc, then the trans cooler, which is often downstream of the raw water pump on the Mercs.

[chpthril]

Confirm your engine as freeheel likely knows the coolant flow in his sleep and knows the potential sore spots.

[BillyZ]

I have an 03' Merc Mag MPI.

[BillyZ]

freeheel4life do you have any ideas?

Thanks

Bill

[civilgee]

Mine did the same thing and the 6” long line between the impeller and the trans cooler was completely stopped up with pieces. Removed line and cleaned out and I am good. Based on the opening at the trans cooler, only small pieces could get by there. Here is a pic of the pieces I fished out. .


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[BillyZ]

At this point I have been through every hose I can get to on the motor, replaced the impeller, and replaced the thermostat. It takes longer to overheat now but still overheats.

Thanks

Bill

[freeheel4life]

At this point I have been through every hose I can get to on the motor, replaced the impeller, and replaced the thermostat. It takes longer to overheat now but still overheats.

Thanks

Bill

A few other things to look for. Good and tight connections on the suction side. If you have a strainer make sure the p ring isn't gone. If air is sucking in instead of water then you can be pulling less water than is needed. A collapsed hose on the suction side can do the same thing. A badly pitted/corroded plastic impeller housing can causeow flow as well.Did you remove the inspection plate on the vdrive and look for any obstructions in the cooler??
A poorly function circulating pump could be to blame as well. Last thing I can think of is a blockage in the risers but only seen that be the cause of an overheat once.