View Full Version : 454 Cooling system

Chris Everhart
03-04-2001, 06:35 PM
" I have a 454 XL engine which seems to be emitting an abnormal amount of steam from the exhaust. It is a closed cooling system and the problem seems to get worse the longer the engine is running. I have also noticed a small decline in the coolant level. In a car, I would think head gasket but I have been reading a lot about the problem with risers and heat exchangers. Any help would be appreciated. "

Stan Davis
03-05-2001, 06:13 PM
" Chris, put a pressure test on the cooling system if you think there might be a leak. With the pressure on the system pull the plugs and crank the engine over, check for water at each cylinder (engine may need to be hot). If there's no signs of water there and with pressure still on the system pull the raw water hoses off the heat exchanger and look for signs of fresh water (if system has antifreeze or water treatment it will be easier to see the leak). To check the riser, you can remove the elbo and the hose from each side and bolt the distribution housing back down with pressure on the system check for leaks. (Again if there is antifreeze or water treatment it would be easier to see the leak) How long have you had the boat, how long have you had the problem and how much water are you loosing? Are the tempatures normal?
Stan "

Jim Dolan
04-02-2001, 01:49 PM
" I've had the same situation with a Mercruiser 454. It has been going on for about three years even after changing the heat exchanger core, but has stabilized and doesn't seem to be worsening or to be causing problems. "

04-03-2001, 04:48 PM
there is a product on the market called rad weld'which will solve your problem it is available'from most auto shops and is simple to use just add to coolent while hot and it will find any miner leakes and seel them hope this helps