97 350, no heat, low temp gauge reading

[Tony_SS]

So I think I have a bad coolant sensor that sends the reading to my gauge because my gauge only reads 150. Also there is not very hot air coming out when the heat is on and the upper hose is lukewarm at best when the engine has been running for awhile... what do you all think?

 

[Daniel907]

I would think thermostat.

 

[someotherguy]

Why would you look at both of those symptoms and think bad coolant sensor? It sounds to me like it's telling you the truth.

Most likely causes: thermostat is missing, stuck open, or way incorrect temperature rating. Also possible: fan clutch stuck engaged.

Richard

 

[kennythewelder]

Theromast most likely. Its an easy and cheep part to change. If that doesn't fix the problem them you can move on to something else.

 

[GT_80]

could be a bad radiator cap too- the radiator cap need to hold pressure in the system to get it to heat up- otherwise the pressure bleeds to the overflow tank and no heat. Get a new cap for like $8, 15psi and see if that helps too- I would do both that and the thermostat

 

[someotherguy]

I think you misunderstand the pressure cap's role in the cooling system. Pressurizing the system raises its boiling point. If the cap was defective, it would still get hot.

Richard

 

[Spastik Monkey]

Start with a thermostat