97BossHammer

Took the boat out for the first run of the season yesterday.......no temp reading on the gauge. I checked all the fuses, and the sensors that are plugging into the tstat housing, all are fine. The gauge appears to be working. When the key is off....the turned on the gauge moves up to the 100 degree position but thats it. I'm thinking the tstat is just stuck open. I replaced it last year with maybe like 1 run on it.....very strange. I have a hard time believing it's stuck but stranger things have happened. What do you guys think?

H2Xmark

next time out open the hatch after a run and feel the t stat cover, it should be pretty warm, if not t-stat might be stuck open, if it is almost hot check your gauge connection at the engine, most of the time it is near the Thermostat cover where the hoses connect up at

groove

Good advise H2Xmark. I almost replaced 3 in a row. The original one stuck open, second one wouldn't open. I pulled this one out and put it in a pot of water on the stove with a thremometer and slowly warmed the water. It came to a boil and was still closed.

I though I was going crazy. So back to the store and got a second replacement. This time I checked it again before putting it in. It opened like a charm, problem was it never closed again.

Back to the store and off to another to find a different name brand and that one actually worked! It opened and it closed.

Long story short, they are cheap little pieces the can break easy and ruin you day...

97BossHammer

yeah tell me about it sheesh. I failed to mention that I did pop the engine hatch and sure enough the tstat housing was not too hot. I could tell the gauge was working though because if you turn the key it would bump up just a little. This tstat is brand new and I've had this happen before with some cars, really ticks you off.

Groove - any idea what brand you went with?

groove

Sorry, it was a long time ago and I parted with that motor a long time ago. I always told myself I would look for an "expensive" aftermarket one if I ever had to do it again. That day never came and I'm still crossing my fingers.

Seriously, check your replacement in a pot of hot water before you put it in. I think I had a few around (new and used) when I did my experiment and was suprised at the difference between them all as far as how much they open.

97BossHammer

I'll do that. I know with cars I've had several do the exact same thing....most usually don't open. I'm gonna be getting it from a local boat shop here so I bet they'll only carry one brand or something. I might just get 2 just to be safe. Sitting here racking my brain trying to figure out why the gauge is not working and sure enough, it's the brand new thermostat that is messed up. Thanks for the reply's guys.

97BossHammer

well I put another Tstat in it and the same thing still happens. The gauge is working because I can take one end and touch it up on some metal and it pegs out. I'm thinking the sensor might be bad....what do you guys think?

97BossHammer

bump

racinbird

97bosshammer, I just had a propblem with cooling on my 97 boss 232 with a 502. I have a cross over installed and when I replaced the old T-stat I installed the wrong new one, it would climb sky high! I removed that T-stat and ran with out one to verify problem, the temp stayed at or just below 100', installed new correct style with top bypass holes, runs normal 155'-170'. Yours sounds exactly like what mine was doing without a T-stat in it. Not sure if that was any help, but good luck! Derrick