1998 PCM Overheating only during idle

[ganderson]

I have a 1998 SNOB. It's equipped with a 5.8 PCM. I changed the impellor, gasket and o-ring for the season.

Yesterday on the river I was testing her out when it started to overheat while idling out of the no wake zone.

Once I got to the upper speeds 25+ the engine cools down and operates at normal range. I pressure tested the water pump and it's properly sealed. I also checked all of my hoses and they seem to be good as well as the strainer. Any thoughts? This is driving me crazy.....

Also there is a black metal tube that is mounted next to the engine where the intake water hoses run into. Anybody know what these are??? Thanks in advance.

[AirTool]

maybe check for vacuum leaks....starting with the strainer.

[vanislwake]

The black metal tube should be the trans cooler, sounds Luke an impeller issue to me but you said you changed it so?? Idk

[Chexi]

Make sure the o ring is in the strainer. That is usually the culprit that causes these symptoms. That, or a partial blockage in the water line (like bits of old impeller).

[GC]

Did you install the pump the same way it came off? Check to make sure the large brass screw on the side of the pump is facing toward the block.

[Nautiquehunter]

I just had the same problem the first time out this year . It was the strainer cup not tightened all the way.

[swc5150]

x4 on your strainer. Got me once too.

[jeffware]

ganderson, i have had engine cooling issues. there was (twice) a rubber raw water impeller that failed, and bits of the impeller were clogging things. on my ski nautique, i had to remove the thermostat housing several times and remove bits of rubber from the thermostat. on my fish nautique, bits of rubber were stuck in the exit ports of the sherwood raw water pump. after removal of this junk the engines ran cool. i know someone that had constant cooling issues and after much time and money, the cap on the stern for fresh water flush was loose. loose cap meant not a good seal, and the raw water pump was not pumping well due to an air leak. jeff.

[gs430]

I had the same exact problem this past weekend on my 216. My mechanic immediately assumed it was the impeller - and I hope he is right. It looks like it could be a few things.

Good luck

[hyparks]

Getting the same problem with my 01 san gt40. Temperature goes up when at idle and runs about 150 when moving at normal speeds.
My water pump was leaking. I stripped it down and rebuilt it. Now its not leaking and I'm still getting over heat problem. I put a new thermostat in last season also. Are there any main areas to check for blickages etc? I will check the strainer next weekend too.

Thanks

[east tx skier]

Also, check the plate between the two halves of the water pump housing. I got rushed one year and didn't line it up properly (with the screws through the holes. So it was sandwiched in there, but not seated properly. Had the same symptoms you describe. Basically, it creates a vacuum leak similar to not having the strainer sealed properly.

[TRBenj]

Overheat at idle, but cool at speed = air leak between the water pick up and RWP. Check the strainer, and tighten all of your hose clamps with a socket (not a screwdriver). Just dont overtighten, paying most attention to the tranny cooler (it will deform and cause a bigger air leak).

[Mikeski]

X6 check the strainer

[nautiquesonly]

Overheat at idle, but cool at speed = air leak between the water pick up and RWP. Check the strainer, and tighten all of your hose clamps with a socket (not a screwdriver). Just dont overtighten, paying most attention to the tranny cooler (it will deform and cause a bigger air leak).

I had the same problem with my 98 Sport overheating at idol only. I changed the impeller, thermostat and then heard a hissing sound (air leak) by the strainer. I took the fittings off and put new teflon tape on both fittings problem solved and it runs around 150 even when we ski for 3 hours or more in the course.