Over heating 170 when running slow

bluexr4

Recruit
Joined
Sep 3, 2004
Messages
1
Have a 170 closed system with 3 inch exchanger, used in fresh water only. drive is new as of last year, motor pump is good. When running slow the temp climbs up close to 200. Loaned the boat to a friend today & he putted around for 20 minutes, noticed the temp was high and shut it off, then headed back after it cooled down. He also said there was a lot of water in the bilge, pumped it out & by the time they got back there was a lot more water in the bilge. I hooked up the ear muffs at home tonight & let it idle for 20 minutes and it stayed at 150 also there was NO water leaking anywhere. The water issue may be a leaking plug. Anyway there is probably rust flake clogging things up. Should I remove the heat exchanger & the riser above the exhaust manifold? is there anything I can check?<br />p.s. had it out 3 weeks ago and ran it fairly hard & it was fine.
 

Hog Wild

Seaman Apprentice
Joined
Aug 29, 2004
Messages
40
Re: Over heating 170 when running slow

90% chance it's your water pick up pump's impeller. Check that before looking any further. Water in the bildge I'm thinking is an unrelated coincidence, but could be a leaking hose. But you'd see the leak with the muff's on. Rust flake, thermostat all will more likely act up not at idle but more like WOT I don't think they are the factor here and wouldn't touch them until I'm sure the raw water flow is strong at idle (meaning that pump is working)
 
Top