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shoe
09-06-2013, 10:33 PM
My 1992 Prostar 205 has a 351 Ford Windsor engine. As of two weeks ago, the engine temp has been inching towards the 200 degree mark. The engine sounds good, starts fine, and has 750 hours on it, but 200 degrees is too hot.

I heard the RW pump whining, so I replaced the entire pump. Major waste of money. The temp gauge, sensor, and thermostat are two years old. I cleaned out the RW intake hose and checked the transmission cooler for blockage. Everything is clear. This evening, I took out the thermostat altogether and the engine ran at 180 degrees, no more, no less. The oil color is of normal wear.

Is the circulating pump my next replacement, or do I have serious problem on my hands? Any suggestions before I take the boat to my nearest dealer?

mikeg205
09-07-2013, 03:00 AM
Check resistance levels on temp sensor and / or check temp with temp gun before you spend major money - are risers to hot to touch?

madcityskier
09-07-2013, 10:58 AM
Dumb question, have you flushed the cooling system to look for partial blockages? They running a hose into the line leading to the thermostat. You should be able to run water through so that it's coming through the exhaust. If so try firing it up that way and see what it does. Could be just a false reeding. Assume oil level is fine and that it has no water in it.

thatsmrmastercraft
09-07-2013, 11:04 AM
Check resistance levels on temp sensor and / or check temp with temp gun before you spend major money - are risers to hot to touch?

This is a great way to quickly tell if your engine is running hot. You should be able to hold your hand on the exhaust manifold and have it just feel warm - not hot.

Cloaked
09-07-2013, 11:42 AM
This is a great way to quickly tell if your engine is running hot. You should be able to hold your hand on the exhaust manifold and have it just feel warm - not hot.
I'm not sure I'd run my hand across an exhaust manifold. Top of the riser? Maybe a better place to practice said remedy......:)

.

thatsmrmastercraft
09-07-2013, 11:46 AM
I'm not sure I'd run my hand across an exhaust manifold. Top of the riser? Maybe a better place to practice said remedy......:)

.

No problem with placing my hand on the side or top of the exhaust manifold, though my old girl likely runs a cooler thermostat.

babymoore3
09-07-2013, 04:45 PM
Is it all the time or just after a full throttle run? Maybe you shut down too soon and overheat?

shoe
09-07-2013, 11:03 PM
I had my wife (you did say wife, right?) touch the engine riser, manifold, and head cover for a temp check. The riser and manifold were warm. The head cover was the hottest, but not burning hot.

As for the flush, do I use a prestone additive directly to the RW intake with a garden hose? Or just run the engine with a fresh water hook up?

Oil doesn't have water in it. Pressure is 60. I did put a 160 degree thermostat in today, but I haven't ran the engine yet.

petermegan
09-08-2013, 12:03 AM
Out of my league here but it could be your circulating pump? Have you pulled your plugs and checked for inconsistencies. Just wondered whether a head gasket on the way out maybe?? Raw Water intake hose sucking flat? Hell just throwing ideas at you. Have Fun.

madcityskier
09-08-2013, 01:01 AM
I'd just run it on cold water. Crushed or leaking hoses are another good idea, restricted flow makes sense. Could be headed toward a circulation pump, but I'm not convinced yet. Sounds like restricted flow somewhere. Try flushing backward through the cooling lines with the hose. I'm leaning toward low flow due to crap built up, but probably because I've had that this week myself.

petermegan
09-08-2013, 04:59 AM
I'd just run it on cold water. Crushed or leaking hoses are another good idea, restricted flow makes sense. Could be headed toward a circulation pump, but I'm not convinced yet. Sounds like restricted flow somewhere. Try flushing backward through the cooling lines with the hose. I'm leaning toward low flow due to crap built up, but probably because I've had that this week myself.

What? Do you need some pears in your diet?? :)

Worthing skier
09-08-2013, 07:02 AM
Hi there

Had the same issue , replaced a few parts as you have done , but it ended up being a bad earth on the back of the gauge .
I would check all the gauge connections .

good luck

Kevin

johnnye23
09-08-2013, 08:00 AM
I had similar temp gauge issues and tracked it down to bad grounds. It was primarily the blower motor ground. My temp gauge would rise 20 degrees anytime blower motor was engaged, I ended up running a separate blower ground to the engine block. Rock steady and consistent temp readings thereafter.

madcityskier
09-08-2013, 06:18 PM
What? Do you need some pears in your diet?? :)

Went with an abundance of cheap beers. Cleared it right up.

shoe
09-09-2013, 10:41 PM
Here is new information which I think is not good. Skied tonight and my wife abruptly stopped the boat while in flight. The engine temp climbed to to 210. When she idled down, I noticed that very little exhaust/pressure was coming out of the port side of the engine exhaust. Other than checking for a banana in the tailpipe, I have no clue where to look. Something is plugged and I no longer think that I have a cooling system failure. Any thoughts on this twist.

Flushed the engine and installed a 160 degree thermostat yesterday. All intake houses to and from RW pump and Circ Pump are fine.

shoe
09-12-2013, 09:45 PM
It took me a couple of days to try all of the suggestions above. This is a little embarrassing, but I found the problem: a bad temp sending unit. I'm a little ticked because I replaced the thermostat and sending unit two years ago as preventative maintenance.

I'm ready to close this out and get back to skiing. Thanks for your help.

johnnye23
09-14-2013, 06:04 AM
That i s great . Thanks for the update