2015 Merc 250 pro XS runs cold

[jrich057]

Model 1250P73BD
Serial 2B017151

Maybe this issue has been beat up, the search function for this forum got an 'internal server error'.

Had a problem with the engine running too cool last year. Replaced the thermostats and it did fine during the warm weather months, but as the season progressed it would occasionally not get up to the normal 130 degrees. Had some down time with trailer issues, but went out on the lake yesterday. The temp on my smart gauge was erratic, and wouldn't get up to 120. Didn't try to run it for fear of a cold seize, just idled around and fished a little.

Was looking at replacing the poppet valve assembly as the next step. Advice or opinions appreciated.

Was going to order the 2 gaskets, poppet, grommet, carrier, diaphragm, spring, screw, and washer. That sound right to those of you who've done it?

[Bob G.]

If it is not reaching 120 degrees at idle RPMs, you have a thermostat issue. Need to check for obstructions.

[Z518 Comanche]

When you clean or replace your stats. Flush it out good

[Nova Kaw 650]

Wouldn't a poppet valve stuck open cause the same problem?

[EuropeanAM]

Wouldn't a poppet valve stuck open cause the same problem?

Possibly- but there would likely also be a problem with very low water pressure.

If you're going to get into the Poppet valve, get with Rhonda. She puts together kits for them (with all the necessary pieces). See her post, pinned at the top of the forum, for Email Contact info.

Better plan on thermostats and gaskets.

[Savage]

I would check BOTH thermostats before messing with the poppet valve.

[Va Phoenix]

My thermostats get debris in them occasionally. Causes my temps to not come up to normal. Have to pull them out and clean the debis(usually pebbles or pieces of wood) and all is good. I always have spare t stat gaskets on hand because it happens so often.

[Kb444fishing]

Mine wouldn't come up to temp. Took both Thermastats out and they were both clean. Put new ones in and all was fine.

[jrich057]

Thanks for the advice, guys. Lot easier to get at the stats, I'll replace them again and flush the system. If that doesn't do it I can't think of what else it could be, so I'll get with Rhonda about a poppet kit.

This a great forum, found out about the compressor strainer here. Cleaned the grass/mud clogged strainer, and avoided a certain compressor failure.

Guntersville grass flats are evil, and there are no fish in that lake. Advise never going there.