496 mag still heating up

[Hagan]

Took boat out two weeks ago and under throttle(3500) boat heated up to 180. Usually runs 160. Replaced impeller and housing. Was in good shape. Flushed system and pulled blue plugs on risers. Flow was great. Long story short engine is still heating up. Last time out I did notice reserve for lower unit oil was dripping pretty good. Would this be correlated to an over heating problem. Any help would b appreciated.

 

[alldodge]

Re: 496 mag still heating up

Are you saying that after the engine heated to 180, you removed and replaced the impeller and housing, or you replaced the impeller and housing before the heat up, or something else?

The oil reserve bottle was dripping oil, right? Where was it dripping?

 

[Hagan]

Re: 496 mag still heating up

Replaced the impeller and housing after the first time it ran warm. Hoped that would fix the problem but it did not. Gear oil is leaking from reserve bottle next to the port side riser. As always any advice on where to look is always appreciated.

 

[alldodge]

Re: 496 mag still heating up

My 502 heats to 180 sometimes depending on how warm the water is after cruising a while. As I idle along going into the dock it usually comes back down to 160 range. It stays up a bit more sometimes these days with the water temp here in KY it's around 87 degrees. My boat also has a 160 degree thermostat. If the engine comes back down around 160 or so you probably don't have an issue.

The gear oil drip may be a loose fitting on the hose. Push the latch away from the bottle and slide it out and take a look, it is all gravety feed to the outdrive and there is no pressure.

What year is your boat?

 

[Hagan]

Re: 496 mag still heating up

1999 baja outlaw sst. Has 320 hrs on motor. Ill give the latch/hose thing tonight and let u know. I'm hoping that works because getting at all of it doesn't look like fun.

 

[Bondo]

Re: 496 mag still heating up

Took boat out two weeks ago and under throttle(3500) boat heated up to 180. Usually runs 160. Replaced impeller and housing. Was in good shape. Flushed system and pulled blue plugs on risers. Flow was great. Long story short engine is still heating up. Last time out I did notice reserve for lower unit oil was dripping pretty good. Would this be correlated to an over heating problem. Any help would b appreciated.

Ayuh,.... Ya say ya got good water flow In, 'n at the manifolds,... Are the risers exhaustin' it Well too,..??

Do ya boat in freshwater, or brine,..??

The oil over-flowin' from the bottle could be from water pushin' up from the drive,..??
Or was the level droppin' into the bilge,..??

 

[Fun Times]

Re: 496 mag still heating up

Did you remove the heat exchanger "end caps" and have a look to see if any debris is blocking water flow?

Item number 32,
http://www.mercruiserparts.com/Show...br=11414&bnbr=170&bdesc=Closed+Cooling+System

Best to start with the port side of the boat end cap.

 

[Hagan]

Re: 496 mag still heating up

Thanks guys. Going back after it now. Busy weekend. The boat is in fresh water and the oil is leaking out in to the bilge. Have not checked the heat exchangers. Going to do that now. Thanks again and ill let you know

 

[alldodge]

Re: 496 mag still heating up

Just to add a bit more so far as heat; taking my cruiser the other day and on the way out through the no-wake it came up to 160. Running on plane (3800 rpm) it's showing 170-172, slow down and idle into cove it comes up to 175 or so, then slowly eases down to 165 before I shut it off. Start back up same thing on the way back except the no-wake zone was longer then the cove so it came down to 160. Current lake temp was 87 degrees.

Have a good one