Running Hot

[WGuaire]

When I get home, I cut the motor and the fan comes on.
  Driving tonight, about 80 degrees outside, some stop lights along the way. The temp guage was consistently at 80 to 90 per cent of the green area on the guage. The coolant is fresh. I was thinking of going for high price coolant. Looks like I'm a candidate for removing and testing the thermostat. Any ideas?
Bill

[fret not]

How long does the fan run after you shut the motor off?

[Walt_M.]

No worries, the fan is controlled by the temperature and when you stop moving air through the radiator the temperature goes up enough to turn on the fan.

[WGuaire]

30 seconds, I'd say.
  I read some older posts on coolant and thermostat. Seems that the gauge staying that high for that long is an anomaly.... that the Vision usually runs cooler normally. Also, the thermostat should get the coolant flowing so the gauge doesn't go up and stay up so high. There is plenty of heat coming off the engine on the right side, where the thermostat and radiator hose live.
  Other than the gauge, I can't tell much while driving.
While cruising, without an endless repetition of stop lights, where does the gauge stay on the dial? Straight up in the mid range or up at the right, 80 to 90 per cent of the green line?

  My concern isn't so much the fan blowing. It happens. My concern is the heat and the cooling system running at such a high end of the range, and not bringing the temp back to the middle of the heat range once underway, getting air again. I am definitely feeling a lack of cooling.
Bill

[fret not]

Previously you stated you have new coolant, but have you flushed the cooling system?  Any material that forms in the cooling system can begin to block free flow through the radiator.  My old Ford Aerostar had so much crud build up in the cooling system that it wouldn't drain when I removed the plug at the bottom of the radiator.  That was a wake up call to me.  Just another thing to check before having total confidence. (I never have total confidence because something CAN go wrong).

[WGuaire]

Previously you stated you have new coolant, but have you flushed the cooling system?  Any material that forms in the cooling system can begin to block free flow through the radiator.  My old Ford Aerostar had so much crud build up in the cooling system that it wouldn't drain when I removed the plug at the bottom of the radiator.  That was a wake up call to me.  Just another thing to check before having total confidence. (I never have total confidence because something CAN go wrong).

fret not - I didn't change the coolant, yet. I'm trying to figure out what comes first, the thermostat test or the coolant.
  I'm not so comfortable with the temp gauge running so high. Doesn't seem normal.
Bill

[Inheritance]

I'm sure everyone on this forum has their own solution to running hot and it's well-documented here. I'm not even running a thermostat and I plugged the smaller bypass hose out of the radiator at the thermostat cover. In theory, you get a constant circulation of coolant.

Does it work? Temp gauge drops pretty quickly once out of stop-and-go traffic and while the fan still kicks on, I don't think it's as often as it once was.

[WGuaire]

Thanks, Inheritance. After stop lights, my temp does not quickly get down. Stays around 80%. I'll test the thermostat.

Bill

[jefferson]

My son had good results with engine ice in his Ducati. You could change out the coolant a lot easier than messing with the thermostat and then if that was called for save the coolant. I don't think it will make enough difference though if yours is running that warm. Did you bleed the air out at the bleeder bolt? Another thing to check is the jiggler in the thermostat which has to be at the top to pass air. Another good thing to consider is a manual switch for the fan.

[Walt_M.]

I finally remembered why the fan runs after shutting off. It's to reduce/prevent vaporlock.

[WGuaire]

I finally remembered why the fan runs after shutting off. It's to reduce/prevent vaporlock.

Good to know, Walt.
  The old thermostat is frozen solid. Yamaha retail price = @$45
Replacement came from Fairfax Auto in Falls Church, VA. $6 and change!!!!!!
The fitment is for a 1993 Nissan Sentra 1.6L.

Before going all Engine Ice I'll try regular coolant and a working thermostat.
Bill

[Walt_M.]

Good find on the thermostat and it just might solve the problem.

[WGuaire]

Did a short test ride this morning. The temp behaved itself. The pics show the old, frozen thermostat and the the new one. One shot of the meters is at start up. The last one shows about the peak heat range. When I got away from stop lights and was able to keep going the temp went toward the center. Good results from a 6 dollar part!
Bill

[jefferson]

Just a word of caution. You may have trouble getting all the air out of the system as that thermostat doesn't have the hole with the rattler in it to release trapped air. You might be able to drill a hole in the new one and remove the rattler from the old thermostat to be installed in the hole.

[WGuaire]

Just a word of caution. You may have trouble getting all the air out of the system as that thermostat doesn't have the hole with the rattler in it to release trapped air. You might be able to drill a hole in the new one and remove the rattler from the old thermostat to be installed in the hole.

I drilled a hole. The 'rattle' part would have to be installed by trick.
  Usually on a water cooled system, riding and checking the level works.