cooling problem

[shaenjay09]

i have a mercruiser 3.0 with an alpha one. i changed the whole water pump kit. took out for 4 weekends straight no prob. 5 weekend started over heating in idle. pulled the hose and ran motor and anything below 1000 rpms and very very small stream of water to almost nothing. anything above and pretty good stream. do you think maybe i pulled sum sand in the impellar and i need to change it again?

 

[cr2k]

Re: cooling problem

When you changed it in the first place was it intact? If not did you find ALL the pieces? If no you need to start from the leg and follow the water hose and find EVERY piece of the old one. Most get stuck in the PS heat exchanger. If they get through that in the thermo housing (which has a small port inside you can not see that often plugs up). If you ran in sand, then yes it's probably bad.

 

[zbnutcase]

Re: cooling problem

Gen 1 or 2? Has engine ever been started out of water or no water hooked to it?

 

[shaenjay09]

Re: cooling problem

gen 1, i never start it without water

 

[Don S]

Re: cooling problem

Time to look at the impeller. A plastic bag over the intakes can take out an impeller.

 

[dingdongs]

Re: cooling problem

if you've pulled the hose from housing and its weak at least you know its between there and the drive.maybe time to pop drive again and see if all is well together with both hoses to make sure all is clear.could even be a melted tube now at waterpump housing.

 

[zbnutcase]

Re: cooling problem

The gen 1 pumps are far more sensitive to dry run, and as Don said something as silly as a plastic bag can wipe impeller in just a few seconds. And idle is where the overheat will show up with burned tips.

 

[shaenjay09]

Re: cooling problem

yah thats what i thought. thanks guys