replaced impeller overheating fluctuation

girls2water

replaced impeller and first time out we threw the oheat alarm.  slowed down and cooled off and then limped home while temp moved gradually from 150 - 180 up and down.  Do I have a blown head gasket, rubber from the old impeller clogging something or a thermostat issue.  Haven't seen this issue mentioned in the strings except head gasket.  Captiva 232 5.7 merc with bravo3.   OH happened fast but only at plane.

buggyjdav

I had impellers replaced and in the process discovered pumps were gouged and needed replacing, runs great now. What did your pumps look like when you did the impellers? Also check the strainer to make sure nothing is clogging water flow.

Dream_Inn

I agree with buggy, if your pump was worn inside, the old impeller may have 'sealed' with those grooves.  now, a new one may not be priming as well.

girls2water

we had remnants of the old impeller floating around in the housing with the thermostat.  cleaned them out and everything is great...thanks I said lets check it and everyone thought I was crazy.  thanks for all the great advice on this site.

jklein

Read the threads on the out drive pickup hose. Many threads including myself. When the obvious cooling issues don't fix the problem (impeller, thermostat, temp sending unit, etc.) for many forum users including myself it was the pickup hose. Sadly this requires the pulling of the boat however once fixed no more temp issues at all!  Good luck. 

duane.mosley

if you have a thru hull water pickup, check the strainer basket. i sucked up mud and i could idle around with no problems but couldn't get on plane without overheating. here are a couple of pictures of what happened to me. good luck.
 

http://rinkerboats.vanillaforums.com/discussion/3708/over-heating-issues#latest

rasbury

theree are lots of threads on this, I had pretty extensive thread with me learning what these pumps are all about....been there done that.