WELCOME TO RIVER DAVES PLACE

496 Heating Up On Me, It Was Not The Impeller

Jyruiz

Next to this Hottie.
Joined
Oct 3, 2007
Messages
1,544
Reaction score
191
Last time I was out on the lake, about two weeks ago my temperature would get to 180 degrees at 3k rpms and would rise even more if I went above 3k rpm's. So I kept the boat under 3k rpm's and figured the impeller needed to be replaced. Well, It was the heat exchange gaskets, check out the pic, my mechanic said he is seeing it more and more on 496 motors, so have yours checked out during your yearly service or if your engine is heating up.
 

Attachments

  • Heat Exchanger Gasket.jpg
    Heat Exchanger Gasket.jpg
    88.8 KB · Views: 190

SS-C

Well-Known Member
Joined
Apr 11, 2020
Messages
233
Reaction score
402
Last time I was out on the lake, about two weeks ago my temperature would get to 180 degrees at 3k rpms and would rise even more if I went above 3k rpm's. So I kept the boat under 3k rpm's and figured the impeller needed to be replaced. Well, It was the heat exchange gaskets, check out the pic, my mechanic said he is seeing it more and more on 496 motors, so have yours checked out during your yearly service or if your engine is heating up.
Don’t see how the heat exchange gaskets would have anything to do with the engine running hot, unless they were leaking very badly.

Now, if your heat exchanger/oil cooler become plugged by debris and, or broken pieces of the impeller, this will cause the engine to run hot.

The pictures you show of the gaskets look to be from overheating, but not the cause of the overheating.
 

Runs2rch

Well-Known Member
Joined
Jun 10, 2013
Messages
9,455
Reaction score
9,445
Those are bad. Change them every 3-5 years.
 

Runs2rch

Well-Known Member
Joined
Jun 10, 2013
Messages
9,455
Reaction score
9,445
Don’t see how the heat exchange gaskets would have anything to do with the engine running hot, unless they were leaking very badly.

Now, if your heat exchanger/oil cooler become plugged by debris and, or broken pieces of the impeller, this will cause the engine to run hot.

The pictures you show of the gaskets look to be from overheating, but not the cause of the overheating.

They get sucked in and block the flow of water.
 

Riverfamlee

Well-Known Member
Joined
Aug 1, 2019
Messages
2,044
Reaction score
4,886
Heat exchanger gaskets. Just had mine done. It’s on my every 3rd season list now.
 

Mcob25rg

Well-Known Member
Joined
Aug 2, 2017
Messages
1,499
Reaction score
2,822
If you take the end caps off to do this, just lake water comes out. - no antifreeze, correct? I’ve had the present HO for at least 6 years, never done it. Seems easy if it’s just the fresh water. How much are the gaskets?
 

Runs2rch

Well-Known Member
Joined
Jun 10, 2013
Messages
9,455
Reaction score
9,445
If you take the end caps off to do this, just lake water comes out. - no antifreeze, correct? I’ve had the present HO for at least 6 years, never done it. Seems easy if it’s just the fresh water. How much are the gaskets?

Just raw water. They only torque to 54 inch lbs if I remember right. 14 Bucks each. Call John Mosetti at Boats Unlimited.
 

02HoWaRd26

DCBroke
Joined
Dec 19, 2007
Messages
11,749
Reaction score
27,754
Also have both coolers back flushed every year, not only the debris from impeller etc, but also sand and sticks build up in there.
 
Top