Overheats at anything over idle speeds, 1989 2.3 engine cobra

[playtime320]

I had an Impeller come apart and installed a new one. Took boat out and it overheats at higher speeds.
I was told there is probably a blockage somewhere. I took apart impeller, T Stat, hoses and flushed everything I could and I have water pressure everywhere but still over heat at higher speeds. I took out the T- Stat and same thing. Where does this rubber from Impeller go when it comes apart and how do I flush this out. Shaft on Impeller turns with motor so shaft is ok Please -HELP.
Thanks In advance

 

[Gettinther]

Re: Overheats at anything over idle speeds, 1989 2.3 engine cobra

I had an Impeller come apart and installed a new one. Took boat out and it overheats at higher speeds.
I was told there is probably a blockage somewhere. I took apart impeller, T Stat, hoses and flushed everything I could and I have water pressure everywhere but still over heat at higher speeds. I took out the T- Stat and same thing. Where does this rubber from Impeller go when it comes apart and how do I flush this out. Shaft on Impeller turns with motor so shaft is ok Please -HELP.
Thanks In advance

Some of your old impeller might be caught in the oil cooler

Have ya tried this:
This test MUST be performed with the vessel in the water. DO NOT
perform this test with the vessel out of water with a flushing
attachment attached.
1. Disconnect the water hose at the raw water pump outlet and then
disconnect the same hose at the inlet on the thermostat housing.
2. Connect a clear vinyl hose of the same diameter between the pump
and the housing, Tighten the clamps securely.
3. Start the engine and drive the boat at the lowest rpm at which the
overheating problem has been observed. Have an assistant (do not do this
yourself-stay at the helm!) check the clear hose for evidence of air bubbles
being drawn through the system.
4. If air bubbles are present, air is being sucked into the system
somewhere between the pump and the inlet holes on the lower unit. Check
all hoses, clamps and fittings for damage or other signs of deterioration.
Check the lower unit water tube, guide, seal, grommet and water passage
cover gasket for damage, signs of deterioration or leakage. Check the pump
impeller plate gasket and housing O-ring for damage and/or leakage.
5. If no bubbles are observed in Step 3, remove the clear hose and
reconnect the original water hose

 

[playtime320]

Re: Overheats at anything over idle speeds, 1989 2.3 engine cobra

Some of your old impeller might be caught in the oil cooler

Have ya tried this:
This test MUST be performed with the vessel in the water. DO NOT
perform this test with the vessel out of water with a flushing
attachment attached.
1. Disconnect the water hose at the raw water pump outlet and then
disconnect the same hose at the inlet on the thermostat housing.
2. Connect a clear vinyl hose of the same diameter between the pump
and the housing, Tighten the clamps securely.
3. Start the engine and drive the boat at the lowest rpm at which the
overheating problem has been observed. Have an assistant (do not do this
yourself-stay at the helm!) check the clear hose for evidence of air bubbles
being drawn through the system.
4. If air bubbles are present, air is being sucked into the system
somewhere between the pump and the inlet holes on the lower unit. Check
all hoses, clamps and fittings for damage or other signs of deterioration.
Check the lower unit water tube, guide, seal, grommet and water passage
cover gasket for damage, signs of deterioration or leakage. Check the pump
impeller plate gasket and housing O-ring for damage and/or leakage.
5. If no bubbles are observed in Step 3, remove the clear hose and
reconnect the original water hose

Yes I have tryed that from the book but no air bubbles just water.
Seams to have enough water pressure still over heats. Where would the rubber pieces most likely go and get stuck?????

 

[Lyle29464]

Re: Overheats at anything over idle speeds, 1989 2.3 engine cobra

Did you follow the hose from the transom to the thermostat housing? It may go to a oil cooler or power steering cooler. That is the first place you look if your getting a good flow at the Transom. When you had the first problem how hot did the engine get?

 

[playtime320]

Re: Overheats at anything over idle speeds, 1989 2.3 engine cobra

Did you follow the hose from the transom to the thermostat housing? It may go to a oil cooler or power steering cooler. That is the first place you look if your getting a good flow at the Transom. When you had the first problem how hot did the engine get?

I ran the hose from the transom to t stat.
I do not have a oil cooler or power steering.
No air in line. Alot of water pressure.
Where do rubber pieces usually end up from Impeller
after falling apart.
I also talked to a tech thjat said I could take out the flapper valve
and leave it out, is that true also?
Thanks

 

[Lyle29464]

Re: Overheats at anything over idle speeds, 1989 2.3 engine cobra

I also talked to a tech thjat said I could take out the flapper valve
and leave it out, is that true also?

He might be drumming up business. If you engine ever diesels your wil fill it with water.
A large wake on the stearn can do it.