omc cobra, running hot

[nealfog]

My omc cobra, with a 5.8 engine, began to run hotter than normal, during my first run of the spring, after sitting all winter.I checked the Impeller,it was fine,but i replaced it anyway. The water flow to the thermostat housing from the outdrive seems to fluctuate back and forth from no flow to a good steady flow. The engine seems to run cooler at higher rpm and hotter than it has in 12 years at lower rpm. Now what??

 

[Gmorris02]

Re: omc cobra, running hot

Have you replaced the T-stat?

 

[P.V.]

Re: omc cobra, running hot

Inspect the water pump housing and inner liner closer. Often, the liner will slightly rotate inside the housing and blocking off water flow. Also look for good integrity of the water house from the bell housing to the inner transom/oil cooler.

 

[nealfog]

Re: omc cobra, running hot

Thanks for the replies. I have changed the thermostat,But I belive the problem is with the water delivery. I have replaced the impeller,and liner.I made sure the liner was centered in the houseing. If I run this with the muffs on, I can see it drawing water from the muffs for a few seconds, then the water will blow out around the muffs for a few seconds, then it starts to draw it in again. this coinsides with the water exiting through the exaust. I test the flow at the hose right at the transom at the inside, I get a good upward streem of water, then the water actually goes back down through the hose, then a good streem again, and so on. I read about seal leaking around the tube from the pickup in the lower unit, and drawing in exaust, has anyone ever actually seen this? or am I way off base with this thing? Thanks to all who take the time to help with this stuff.