Engine Won't heat up

[Reming870]

I cannot get the motor to heat up. Tried two thermostats and two different temperature sensors. Both thermostats and sensors were used. I noticed this the other day in the water when I saw the temp just above 100. Boat always ran around 160.

Assuming the thermostat was good, what can create this?

I will try a new thermostat tonight, but I am not confident this is the problem.

The temp gauge is accurate. I checked it with a surface probe and was within 10-degrees. I measured 95 with the surface probe.

Testing has been done in the driveway on muffs with 65 degree water. Water was 62 when I noticed it originally.

Seems strange that I cannot create heat even at an idle.

 

[sethjon]

Re: Engine Won't heat up

I cannot get the motor to heat up. Tried two thermostats and two different temperature sensors. Both thermostats and sensors were used. I noticed this the other day in the water when I saw the temp just above 100. Boat always ran around 160.

Assuming the thermostat was good, what can create this?

I will try a new thermostat tonight, but I am not confident this is the problem.

The temp gauge is accurate. I checked it with a surface probe and was within 10-degrees. I measured 95 with the surface probe.

Testing has been done in the driveway on muffs with 65 degree water. Water was 62 when I noticed it originally.

Seems strange that I cannot create heat even at an idle.

Make sure the t stat is not in backwards. Then blow out the hoses to see if there is a blockage.

 

[Reming870]

Re: Engine Won't heat up

Put the new stat in last night, blew out all the lines.

Same Problem. Cannot get above 110 degrees.

Any other ideas.

 

[EddiePetty]

Re: Engine Won't heat up

......I cannot get the motor to heat up. Tried two thermostats and two different temperature sensors......The temp gauge is accurate. I checked it with a surface probe and was within 10-degrees. I measured 95 with the surface probe.........

....digesting the above, and assuming the 'surface probe' measurements were taken in ambient conditions, by any chance is your temperature sender installed with teflon tape on the threads thus insulating the sender from the block?

 

[BAproject]

Re: Engine Won't heat up

Have you checked with an IR temp gauge, is it indeed not getting hot.
Shoot the temp gauge at where the sending unit is and get a reading, does it match the gauge on your dash.

What are the risers reading (they should be noticeably cooler)

Check temp on block and make sure it is not actually running hot. I have read some posts that claim gauge read cold, but engine was actually on the verge of overheating.

 

[Reming870]

Re: Engine Won't heat up

I'll check it with an IR tonight, but feeling around while running, everything was warm (not 160) to touch. I could keep my hand on the water outlet easily. If I shut-off the water the temp gauge would rise, but I did not test how long or how far in fear that the gauge reading is wrong. I also pulled the stat immediately after shutting it down and it was still closed fully.

No teflon on the sender. I even strapped a different ground wire to it to test. The gauge light is on so I assume the gauge ground is OK as well.

Maybe just a bad gauge, but the engine feels cool to touch.

 

[BAproject]

Re: Engine Won't heat up

I almost wish I had this problem....mine is running too hot

Check with IR and see what you find....do you have a 140 t-stat in there?

if so, 140-150 would be ideal engine temp (if running in sea water)

-BAproject