Alarm went off, Why?
 

Hi everyone. I just purchased a 2000 Baja 232 with the 7.4L engine. Today on the maiden voyage after being out for a few hours the alarm went off. I shut it off and opened the hatch to see if I could see anything. Nothing visible looked wrong. I did touch the top of the exhaust manifolds and they were pretty hot. Starboard side maybe a little hotter. The temp was up to 200 when I shut it off. Restarted it after about 5 minutes and the temp went back down to 150 then it seams it would go up and down and the alarm would go on after a little bit of idling forward. Shut it off for a bit. Restarted and started heading back to the dock. Took about 20 minutes to get back to the dock and the alarm sounded again just as we were pulling in. Any help here would be greatly appreciated. One other thing I did notice a slight white “steam” coming out of the back while running and when I had it shut off one time I could hear like a slight boiling sound in the manifold on the port side.

when was water pump impeller last replaced? I would remove it and check condition?

Only three things cause it, overhear, low oil pressure and low drive lube in reservoir. Sounds like it needs an impeller and back flush it while you are in there.

Thank you. I’m going to look at the impeller today. It doesn’t look easy to get to.

I hope you can do some contorsion type moves, because you will practically need to stand on your head to change pump.

Haven’t removed the impeller yet I am checking for blockages first. Spun the impeller by hand and it does have some resistance. I found out the power steering cooler is a wide open passage so the next place to look is the fuel cooler. My question is there a restricted inside of that or is it wide open like the PS cooler?

All the coolers PS and oil Ive seen have the tubes running through them, if its cool fuel it will be wide open or at least the ones Ive seen..........If you find no blockage it could be a faulty T stast, 200* + the rubber hose will start to melt if you have that on you exhaust

So if the cool fuel is wide open I shouldn’t have to check there for blockage and just move to the oil cooler?

Id check everything to rule it out, large enough pieces can get lodged in a 1 in opening, getting to the cool fuel pump will be a challenge

Before I check the other passages should inspect the impeller to make sure it’s still intact. And if it is move on to assume it’s the thermostat and just replace the impeller for maintenance sake?