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6V92 run over 180 temperature

January 15, 2014, 02:51:47 am

When leaving Quartzite / Borrego Springs last year I experienced abnormal heat on my temperature gage.

It had always ran about a needle width above the 180 degree mark. While proceeding to San Diego I noticed it was going 2/3 of the way between 180 and 200 and cycling back to 1/3. It had never done that before.

That continued through 3500 miles of driving through spring, summer, fall and winter ambient temperatures. Regardless of outside temperature

UNTILL YESTERDAY !!!

I had both the thermostats (180 degree) and the 185 degree switch that controls the fans replaced.

On a 80 mile test drive (60 degrees OAT) my temperature gage stayed a needle width above 180 and no cycling of fans !!!

I tried 1st 40 miles with the Air conditioning off, second leg I had A/C on full, still reading the same and no cycling of the temp or fans.

YEA!!!

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Re: 6V92 run over 180 temperature

Reply #1 – January 15, 2014, 06:00:46 am

Looks like you found your problem. Like Brett Wolfe says thermostats are a normal ware item, I change mine every 2 years.

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Re: 6V92 run over 180 temperature

Reply #2 – January 15, 2014, 10:45:05 am

Bill,

Good you caught it as they never fix themselves. Fan coolant sensor is something most would miss. Ours also runs a needle width or two above 180. A test drive is excellent prep for the Quartzsite trip for anyone, especially if the coach has not been used in the winter.

Pierce

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Re: 6V92 run over 180 temperature

Reply #3 – January 15, 2014, 10:51:14 am

Holy cow!      I've never changed the thermostat in Forrest in 10 years!  If OAT = cold, gauge is at just below 180F;  If climbing or very hot OAT, about 185F ... so far.  I should change the thermostat anyway...been lucky so far, I guess.

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Re: 6V92 run over 180 temperature

Reply #4 – January 15, 2014, 11:33:47 am

Bill,
Good dectective work!

My temp gauge never went above 180 on my recent round trip from Gulfport to Nac (roughly 1000 miles) even though I lost about a gallon and a half of coolant due to loose clamps on the big water pump hose. Tightened em up and no more leaks.  Probably time to change the thermostat and fan coolant sensor like Brett Wolfe and bbeane recommend.

Pierce,

Where are the thermostat and fan coolant sensor located?  I need to look at replacing  the hoses also as I am using the coach more often and I want to do some preventative maintenance in the spring.  With the humidity, summers can be brutal here.

Thanks Guys,

Jerry aka Murph

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Re: 6V92 run over 180 temperature

Reply #5 – January 15, 2014, 12:33:41 pm

@Bill That's awesome! Where did you have your work done?

I've been chasing this for a while too. My high/low switch was disconnected by the PO sometime in the past. When I first got the coach I had no problem with temp but over the last year and a half I have to drive with my eye on the temp gauge. I'm thinking the thermostat isn't opening fully since the high/low switch has never worked. I would like to get it working correctly though.

See you at Q!

see ya
ken

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Re: 6V92 run over 180 temperature

Reply #6 – January 15, 2014, 05:38:26 pm

Jerry,

The thermostat housing is right by the block heater. The temp sensor there is for the DDEC. If I remember correctly and it goes over 210F (higher on some) , the computer goes into shutdown mode.  The fan sensor is on the opposite side of the engine. Ask Bill for the part number on both thermostat and sensor.

The hoses are lifetime blue silicone. Don't ever need replacing plus cost is per inch on that stuff. The hoses leading to the front for heating are not the same material.

If you have trouble seeing the instruments and the warning lights at the same time because of the steering wheel, try glueing an aluminum strip on the underside of the dash, just above the warning lights to reflect them.

Pierce

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Re: 6V92 run over 180 temperature

Reply #7 – January 15, 2014, 07:55:12 pm

Be aware that the quality of thermostats, like everything else, has decreased noticeably over the years. I've bought several new thermostats that didn't open anywhere near the temperature they were supposed to. I never replace a thermostat unless it fails because it's difficult to find a new thermostat that's as good as the original. I always test the thermostat in a pot of boiling water with a calibrated thermometer and watch to see what temperature the thermostat opens at. Most of them are way off. Don't forget that you'll need to find two thermostats that both open at the correct temperature for the 6V92TA, because it has a thermostat in each cylinder head. You'll probably want to buy a bunch of thermostats and test them all, then install two that work properly.

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