1996 sea ray 215 Express Cruiser 5.7L

[Ed Harris]

This is a new to me rig. Was inquiring about how warm this engine is supposed to run. At idle it runs 190 and while under way at 3/4 throttle still runs 190.
0F790518 engine serial number.

 

[alldodge]

If you have open cooling then it should have a 160 degree thermostat. If you have closed cooling then it would have a 180 degree. The Stat may have been changed and so long as your not in salt water and raw water cooling there is no harm. Some will change to a hotter Stat thinking it would run better.

It can also be the gauge is off. You can check with an IR temp gun and see what the Stat housing measures

 

[hnt]

My 1996 5.7LX EFI, raw water cooled, 160 degree thermostat, shows 175 degrees on the gauge

 

[Bondo]

Ayuh,..... If my heat gauge said 190*, I'd be cross-checkin' it with a point, 'n shoot thermometer,.......

AD explains it all quite clearly,......

 

[Ed Harris]

While running the Boat on the hose today gauge was still reading 190 but water being dumped out at the transom was not 190. You could hold your hand under it and hold it there like bath water. I am figuring I could have a bad gauge. Would I be thinking correctly?

 

[hnt]

As Bondo said use an infared thermometer to see before buying parts. They are super cheap at Harbor Freight and are a must have tool for boating (cooling issues ) and if you trailer your boat (tire temps and wheel bearings). I even have a fiend you uses it to get the frying pan just right for making omelets. Lol

 

[Ed Harris]

Checked with the previous owner and he informed me that he swapped to a 170 west marine t stat when he installed new risers last spring. Just got the temp gun today so I have not checked with that yet. Will the 170 make it run around 190 ish? And what was the original degree t stat in these engines ?

 

[Rick Stephens]

With open cooling in fresh water, much above 160 degrees ƒ actual in the water jacket of the motor will allow bubbles to form on the cylinder/jacket walls. The temperatures go up on the cylinders and heads because of that. Hence you see a lot of 140 and 150ƒ thermostats on open cooled systems. With closed cooling the system maintains a 15 psi pressure and those bubbles won't form below 220ƒ. So those systems can have 190-210 thermostats and the fuel will burn a little more efficiently.

Rick

 

[Ed Harris]

Used the point and shoot today. Engine idling and water temp on the gauge was reading 180ish but the t stat housing was reading 140. Going to pull the sending out and put it in hot water and shoot the water with the gauge and compare.

 

[QBhoy]

Temp gauges are wildly not accurate usually. But good to be cautious.