Forum Discussion
Is this MH new to you or have you owned it for years. If it's been yours for years and it is suddenly reading high then it's a concern. But if it's new to you then as Grit says it may be normal.
If you really want to know you can go buy a $23 Infrared Laser Thermometer from Harbor Freight. Run the MH down the road until the gauge is where you are concerned. Then pull off to a parking lot and shut the engine off. Take the temperature from the housing where the upper radiator hose connects to the engine. If it's 190-220 I wouldn't worry about it.
Technically the MH belongs to my mom and late father.  I am trying to sell it for my mom.  I believe my dad had it checked and it had always ran in this range but I can not be sure of that.   My mom seems to believe that is correct also but she never drove it and is not sure either.  
I drove it 330 miles and it never went above the A.  That was cruising down the interstate at 70.  
I have an infrared temp gun so will get out this weekend and try that.   
Thanks!
- Grit_dogMay 14, 2025Navigator IIIf you ran it 330miles and it didn’t overheat, slap a for sale sign on it and move on. 
 Don’t see much value or return in performing major services to 30 year old RV for sale.
 if anything, as a buyer I’d wonder why there was a list of stuff all done to it last week or last month.
 I mean unless the coolant looks like diarrhea or something obviously detracting from the sale value.