still over heating ,I need some help

[madera]

volvo aq130d(4 cyl-draws cooling water from lake w/oil cooler, i believe water jackets cruded up with sea corrosion. seller stated hardly ever used in salt h2o. my problem now. what can i do to open up water passages to allow improved cooling, have replaced impeller, checked for suction leak from stern drive, pulled mixer elbow seems ok, removed themostat. lake test showed at dock temp would go to 180+ @1500rpm when rpm increased to 3000 temp down to 140. put in drive temp wanted to steadly increase to 210. what do you think, i need some help, is there any type of flush i could add to clear out corrosion, remove head, what do I do?

 

[Ralph 123]

Re: still over heating ,I need some help

Read this closely:<br /><br /> Exhaust Tips

 

[Hunky Dory]

Re: still over heating ,I need some help

Perhaps this is obvious but I haven't noticed a reference:<br /><br />My penta 4 cyl. has a raw water filter ahead of the water pump on the front of the engine. Follow the input hose back from the water pump to a stainless canister with the look of an inverted tuna can. It has brass thumb nuts on top and it collects grass, bugs, styrofoam, fishing tackle and other gooey flotsam.<br /><br />Blocked raw water circulation == reduced cooling. <br /><br />It is supposed to be easy to service but mine defies that description. I remove the thumb screws, push the stove bolts out the bottom and then misalign them slightly to press on the top instead of going thru their holes. Steady the mount with one hand, hold the screw with another and tap, press, pound, push and twist with the other. If you only have two hands you may get to experience the joy of fishing around in the bilge for dropped screws; but the device will eventually open for inspection/cleaning.<br /><br />I'm open for suggestion on revising this method!