Chrysler 360 overheating

"The raw water pump seems to b

"The raw water pump seems to be pumping fine and the exhaust elbows stay cool, but the centrifugal pump does not appear to be circulating water in the engine. I've removed the thermostat and checked all the hoses for blockages. Is there anything else I should do, or has the centrifugal pump gone bad? I found this diagram on in another thread and it appears to be the setup that I have.

"

Your circulating pump might no

Your circulating pump might not have and blades left on it. Better pull it and take a look.

Jeff

"I pulled the pump off this af

"I pulled the pump off this afternoon (and the raw water pump and alternator to get to it) and the blades still on the wheel. There is about a 1/16 of an inch gap between the blades and plate. The connection between the wheel the blades attach to the and the wheel the belts attach to is solid (no give), so the pump should be pumping?




I took a look at the hose attachments and the diagram again and it's not quite the same. I have a hose that runs from the top of the engine where i removed the thermostat to the top of the heat exchanger. From the bottom of the heat exchanger is a hose that runs to the large hose connection on the pump. There is a hose that runs from right beside the thermostat hose on the pump side of the engine to a T junction, and each side of that has hoses that go into the bottom of each of the manifolds on the transmission side and then 2 hoses that run from the top of the water pump side of the manifolds to a T junction that connects to the top of the water pump.



When I run the engine at idle, it takes about 3 minutes to reach 190 degrees which is where i kill the engine. At that point the water pump side of the manifolds are hot, but the transmission side is still cold. The hose that runs to the top of the heat exchanger is hot on the engine side and cold on the exchanger side with the thermostat removed.

Any idea on what is going on or what i should try?"

"I'm stunned at the amount

"I'm stunned at the amount of rust on that pump, considering that this is a fresh water cooled engine--and that might be your problem.

Question: Was this motor originally raw water cooled? If so, there must be handfulls of rust flakes floating around in there and plugging your heat exchanger.

Please respond.

Jeff"

"I don't know the answer t

"I don't know the answer to that. I purchased the boat about a month ago. There are receipts on the boat from when it was repowered back in 1990. I'll look at them and see if there is any mention of the cooling system.

When the engine overheated for the 1st time, steams and water came pouring out of the radiator cap and it was a rusty brownish/green color.

When i pour water into the radiator cap of the heat exchanger, it seems to flow out of the hose that goes into the water pump freely.

Would you like more pictures of anything?"

re: "Would you like more p

re: "Would you like more pictures of anything?"

Yes. A Picture of Megan Fox working on your motor. That would be helpful.

"Hold it! Was there 50/50 wat

"Hold it! Was there 50/50 water antifreeze in there or just pure water? If the later, you are in trouble!


Though called "Fresh Water Cooling", it's not; it's anti-freeze and water cooling.

Jeff"

"It was water and antifreeze.

"It was water and antifreeze. Once all of the rust settled out of it, it was a pretty green color in my bilge."

"check for compression in the

"check for compression in the cooling system.
Water pump can not pump air,or exhaust gas.
You can check 3 ways.
1 Gas anelizer= hc in cooling system.
2. because you have closed system cooling
system you can put a preassure tester on your fill opening. start the engine . If it climbs
to something like 15 to 20 #in a couple min. You have compression in your cooling system.
3. pull hose off thermostat housing
start engine. If it is pushing air out you have compression in the cooling system.
Poss Head gasket to cooling chamber leak,
cracked head or poss block.
Let us know
David"

"Since you have the pump off ,

"Since you have the pump off ,start the engine
See if it's pushing air out water pump holes
you only need to run it for about 20 sec"

"I am replacing the hoses and

"I am replacing the hoses and drained the antifreezed from the FWC on my Chrysler m360. The manual does not explain the procedure, mixture (assume 50/50 mix) or amount of new antifreeze I need to add to the system.

Does anyone have any suggestions or intructions on adding the new antifreeze and when you know you have added enough?

Thanks"

"50/ 50 mix. run it till therm

"50/ 50 mix. run it till thermostat opens . then top off. If it does not open by 190 shut it down. Loosen hose clamps purge air, wait a few min and try again.
I think you have something else going on.
David"

I fear you have lots of rust f

I fear you have lots of rust floating around in there.

Jeff

Thanks for the input everyone.

Thanks for the input everyone. I havn't had a chance to work on it since I took off the pump. I'm planning on removing all the hoses and trying to flush everything out later in the weeks and see what happens.

I had to change one of the cir

I had to change one of the circulating pumps on my raw water cooled 360s and it looked far better than yours. Virtually no rust by comparison.

There's got to be handfuls of rust flakes circulating inside there.

Jeff

"I found the problem. It was

"I found the problem. It was one of those staring you in the face type things. The hose that returns the water from the engine to the heat exchanger was not tie wrapped down and as such was doing it's best St. Louis arch impression raising it about 2-3 inches above the top if the heat exchanger tank. The centrifugal pump wouldn't pump the water up over the hump.

When the engine overheated, the temperature gauge was ruined/recalibrated. When the engine is cold it reads 140 and hot it reads 235. I took my infrared heat gun down and testing the engine everywhere. The hottest anything read was 165. Is that something I can fix or just need to replace the heat sensor? Also where is the heat sensor and what does it look like?"