overheating

[clt400]

have a 7.5 cobra that is overheating. took the thermostat out to see if that was the problem, still overheated. after asking a few people, someone told me that the engine could overheat without a thermostat even if there were no other problems with the engine. omc manual says do not run without the thermostat. anyone know if this is true
thanks

 

[Gettinther]

Re: overheating

have a 7.5 cobra that is overheating. took the thermostat out to see if that was the problem, still overheated. after asking a few people, someone told me that the engine could overheat without a thermostat even if there were no other problems with the engine. omc manual says do not run without the thermostat. anyone know if this is true
thanks

Yep it's true, Check your impeller it's likely had it

 

[HT32BSX115]

Re: overheating

have a 7.5 cobra that is overheating. took the thermostat out to see if that was the problem, still overheated. after asking a few people, someone told me that the engine could overheat without a thermostat even if there were no other problems with the engine. omc manual says do not run without the thermostat. anyone know if this is true
thanks

Howdy,


Your engine will overheat if there isn't enough flow from the raw water pump.

It will also overheat if the exhaust manifolds and/or risers are clogged with rust. (good luck buying new ones)

If you have have not checked for impeller fragments or other debris clogging your oil cooler or power steering cooler, now would be a good time to do it.

You're right. DO NOT operate it with the t-stat removed.


Regards,


Rick

 

[clt400]

Re: overheating

impeller looks like new

 

[HT32BSX115]

Re: overheating

impeller looks like new

You'll have to do a little more troubleshooting then.
the hose that goes from the transom mount to the t-stat housing.

Start the engine while holding the hose over the side and see if water flows freely.
(this will check water flow from the water intake/raw water pump to the supply hose)

If you have good flow, check the oil and power steering coolers for blockage.

If they're clear, check the t-stat housing for debris or impeller fragments etc.

Once you've checked the raw water lines, you can put the boat in the water with the raw water hose disconnected.

Start the engine and see if the raw water pump will pump a good flow of water from the "lake"

if it does, then you may have blockage elsewhere.