www.iFourWinns.com

I have a 1998 Horizon RX 4.3L SX. When I'm idling or going slow it reads low mid 160's, but when I get up to speed it lowers to a rock steady 140. Is this something to be concerned about? It's doesn't seem to be overheating. It has 160 temperature gauge installed. Seems to be normal operation to me...faster more water..thus cooler temps. Thanks

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1998 FW Horizion RX 4.3GL SX Drive
Garmin 530

This is completely normal. Cheers!

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08 H240 5.7 GXi/DP/Volvo Penta
08 F150 Supercrew Lariat

Yes...nothing wrong here. Its pretty simple...when you are at idle, the water pump is turning a little slower, so the water has time to heat up slightly since it stays in the block longer. When you are motoring along, the water is pumping through very quickly and has less time to absorb the heat. The constant flow of fresh lake (or ocean) water that is cool is taking the heat out of the block much faster.

Keep in mind, cars operate in the 180-210 degree range all the time.

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Current Boat:
2004 Sea Ray 320 Sundancer "Nauti Luvin'"

Previous Boats:
1999 298 Vista "Seas The Day"
2008 H200SS "Nauti Luv"
2006 Tahoe Q4

I agree that is pretty normal...mine can vary with the water temp from spring to summer (ranges from 45-70 degrees) and engine rpm....idleing it will sit at 160, a quick run on plane it will drop a little (145-150) and eventually stabilize at 160....the only time you need to do anything about it is if the thermo starts sticking, then it won't warm up to more than 100 unless you run on plane..that's too cool....
Here in salt water we change and or clean thermostats often...sand or rust particles tend to cause sticking....I usually put in a new one when I winterize it....

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88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

Thanks for all the feed back. It's nice to know that there isn't a problem.

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1998 FW Horizion RX 4.3GL SX Drive
Garmin 530