Engine overheats briefly

[ride_everyday]

mainly while idling I will notice my engine temp will go up to 240+ but then quickly go back to 160. I took the hose off the trans cooler and found some seaweed and (old) impeller pieces and cleaned it out. I checked the impeller and it was fine. All hoses and clamps seem tight. But I today I saw the temp go up to 240, I stopped the engine, restarted and all was fine for the next 2 hours of riding. The temp would sometimes go up a little past 160 but come right back down. Could this be a bad T-Stat?

Also after a few hours of riding, the beeper would come on during idle. All gauges read ok, but the RPM were a little low (around 500) normally the engine idles around 550. If I throttle up 50 RPM the beeping stops, I suspect the oil sending unit. (oil is about 25 hours old)

I would like to replace the sender, looked on SkiDim but not sure what sender to get.

The boat: 2001 Wakeseter VLX

Engine: Indmar 315HP (GM)

Any help would be appreciated!

[dihrdskir]

mainly while idling I will notice my engine temp will go up to 240+ but then quickly go back to 160. I took the hose off the trans cooler and found some seaweed and (old) impeller pieces and cleaned it out. I checked the impeller and it was fine. All hoses and clamps seem tight. But I today I saw the temp go up to 240, I stopped the engine, restarted and all was fine for the next 2 hours of riding. The temp would sometimes go up a little past 160 but come right back down. Could this be a bad T-Stat?

Also after a few hours of riding, the beeper would come on during idle. All gauges read ok, but the RPM were a little low (around 500) normally the engine idles around 550. If I throttle up 50 RPM the beeping stops, I suspect the oil sending unit. (oil is about 25 hours old)

I would like to replace the sender, looked on SkiDim but not sure what sender to get.

The boat: 2001 Wakeseter VLX

Engine: Indmar 315HP (GM)

Any help would be appreciated!

Ride everyday,

Try the thermostat. They can stick and you can get hot before they open. I'm surprised the engine management let it get that hot without going into limp home mode. My 07 rlxi had the same problem last year after it had been sitting for a while but only when running it from cold. Once it opened it would work normally.

re the oil. replace it first and see what happens. If it continues to beep put a mechanical gauge on it to see what's happening with oil pressure at idle before replacing anything. How many hrs on the engine?

[ride_everyday]

mainly while idling I will notice my engine temp will go up to 240+ but then quickly go back to 160. I took the hose off the trans cooler and found some seaweed and (old) impeller pieces and cleaned it out. I checked the impeller and it was fine. All hoses and clamps seem tight. But I today I saw the temp go up to 240, I stopped the engine, restarted and all was fine for the next 2 hours of riding. The temp would sometimes go up a little past 160 but come right back down. Could this be a bad T-Stat?

Also after a few hours of riding, the beeper would come on during idle. All gauges read ok, but the RPM were a little low (around 500) normally the engine idles around 550. If I throttle up 50 RPM the beeping stops, I suspect the oil sending unit. (oil is about 25 hours old)

I would like to replace the sender, looked on SkiDim but not sure what sender to get.

The boat: 2001 Wakeseter VLX

Engine: Indmar 315HP (GM)

Any help would be appreciated!

Ride everyday,

Try the thermostat. They can stick and you can get hot before they open. I'm surprised the engine management let it get that hot without going into limp home mode. My 07 rlxi had the same problem last year after it had been sitting for a while but only when running it from cold. Once it opened it would work normally.

re the oil. replace it first and see what happens. If it continues to beep put a mechanical gauge on it to see what's happening with oil pressure at idle before replacing anything. How many hrs on the engine?

Thanks for the reply dihrdskir,

I will pull the boat out this weekend and do an oil/filter change- the oil is looking a little dark anyway. At the same time I will replace the thermostat (easy and cheep repair).

When It went to 240, there was no beeping or limp mode.

The engine has 700 hours. Runs fine otherwise.

[skier92]

Not sure about the hoses on a VLX, but on my 99 Respnse with 325 Monsoon ,the hose between the raw water pump and the trans oil cooler drops downward from the pump and then is turned upward towards the cooler. It is possible there is more debris in this hose that only works its way to the cooler when water is flowing. Take the hose completely off the engine and flush out. While your'e at it, remove the top hose from the trans cooler and flush the cooler out. Also remove the inlet hose from the raw water pump and look for debris in either port from the pump. Also a good time for a new impeller if it hasn't been replaced recently. Back flush inlet hoses while un-hook form pump.

[Ebertsch]

Also make sure that all hose connections are tight and that the cover plate over the impeller is tightened down. If any air manages to get in the pump loses its prime and you will get that cooling then loss of cooling effect. The impeller is a self priming pump and if any air can get in on the suction side, it loses it priming effect.

[BuFootin]

Also make sure that all hose connections are tight and that the cover plate over the impeller is tightened down. If any air manages to get in the pump loses its prime and you will get that cooling then loss of cooling effect. The impeller is a self priming pump and if any air can get in on the suction side, it loses it priming effect.

My bet is it is a bad impeller. Check the condition of the impeller itself and replace if it is worn. This will certainly cause no or lack of water flow at low idle speeds causing the temp to rise above 160. As you run the boat at cruising speed or riding speed, the water flow increases and properly cools the engine.

[ride_everyday]

Thanks for all of the responses, I will replace the impeller and flush the system. I have checked the hose clamps, they seem tight, but when I get the boat into the garage I will do a thorough inspection of all the hoses clamps and fittings.

Thanks again! You guys rock!

[ride_everyday]

The impeller did look good when I pulled it a on Monday, but I will replace it anyway. I will keep the old one on board for backup.