Why is it still getting hot

[Mosslanding831]

Hello out there I have a 1994 OMC cobra 5.0 I changed the impeller the water pump thermostat change the oil clean out the manifold check the water coming in through the back and follow it all the way up to top and there's water coming through but it's still getting hot I can't figure out why I have an idea to run an extra pump to bring water in because whenever I hook up a water hose to it and it's in the water it does fine with the water hose in it and the sea water it stay at a good temperature but what else would please someone out there help me thanks

 

[Horigan]

Welcome. You need to rephrase your question with some sentences. I can't understand your issue with no punctuation.

 

[Mosslanding831]

My 1994 OMC COBRA is overheating.i changed the water pump,the thermostat, impeller I change the oil and I cleaned out the manifold and it is still getting hot. What else can I do.

 

[jimmbo]

Manifold? Is this a Closed Cooling System?
Is the overheat specific to idle, part Throttle, Wide Open, or all the time?

 

[Mosslanding831]

Im not sure how would I know and what does that mean.

 

[jimmbo]

Raw water cooling is where water taken out of the lake/river/ocean and is run thru the engine, Closed Cooling is where the engine has a closed loop of coolant that remains in the engine and its heat is shed in a Heat Exchanger that has the lake/river/ocean water going through it. You mentioned Manifold, so I was wondering if you were referring to a Heat Exchanger

 

[Mosslanding831]

Water runs through it.

 

[Mosslanding831]

Water runs through it

Water runs through it .what should I do

 

[Mosslanding831]

I do thank you for you time I'm just lost and I don't know what to do.i don't have the money to take it to a shop and I need to get back out there to work.

 

[flashback]

Start with some new exhaust elbows, I am dealing with much the same..I had to replace the port side, now the starboard side is running a bit hot.. I've come to the conclusion that it's a balancing act and the water needs to flow equally through the entire system...

 

[itsathepete]

Remove the engine drain plugs on the port and starboard sides. See if a bunch of rust flakes or chunks come out or if they are clogged. Buildup of rust and crud in the engine block reduces cooling efficiency. Flush the engine block with fresh water by removing the thermostat housing.

 

[Mosslanding831]

Ok thank you I will do that frist thing in the morning and let you know thanks

 

[Horigan]

These infrared guns are helpful in diagnosing temperature issues. Aim it at your thermostat housing to confirm it's operating at the rated temperature (140-160F). Aim it at the top of the exhaust elbows to confirm you're getting good flow through each (temps no greater than 120F and fairly close to each other). If the elbows are hot, then they need to be replaced, along with the associated exhaust manifold.

https://www.amazon.com/Etekcity-Lasergrip-774-Non-contact-Thermometer/dp/B00837ZGRY

In addition to flushing the block, as described above, I would back flush the rest of the system; disconnect both hoses from the raw water pump and back flush from the pump inlet house out to the drive and from the thermostat housing to the pump outlet house.