HI I have a 86 Mazda B2000 and it overheats when I get on the freeway driving less then a mile then it goes down and it stay just above the half mark I replaced the hose going into the radiator , cap , thermastate its not leaking coolant anywhere., also my gas gauge reads only to the half a tank or doent read at all.

 

Have you actually measured the actual temperature of the cooling system?

 

Generally coolant heating issues should be the opposite what your are having. On highway speeds up to about 60 mph with ambient temperatures not exceeding 80F the air moves better around the engine compartment and increasing the cooling effect . Just like air cooled Motorcycles.
You also mention other dash indicator issues?

So I would:

Check all coolant levels. If any are low *add water only not coolant
Check the hose upper and lower temperature... the lower will be slightly cooler then the top.
Check you battery by load testing it. (go to a place that sells batteries and they generally can do this for you for free)(you are in *N. Ca. so O'Rileys or AutoZone will do this for you for FREE)
Check the temperature sensor connections.

 

Check your coolant for hydrocarbons, you might have a blown head gasket. You can also try taking the radiator cap off, starting the motor and watch for any little puffs of smoke. If you have a pretty good head gasket leak you might see these puffs. But just because you don't see them, doesn't mean you don't have a leak. But if you see them, there's no question. Good luck.

 

NO I havent how do i do that

 

No how do I do that ?

 

Ok thanks

 

One way that works and is very accurate.
After a short drive to get everything to the operating temperatures.
Check the coolant temperatures at radiator hoses both upper and lower and compare then with how the dash gauge is register.
Top (upper) hose

Bottom(lower) Hose

 

And if yo don't have a MiniTemp I am sure you have this in your kitchen that is very close, at least to get a general idea what the temperature is.




And yes it does work for all the other who are looking a this and going WT* ! lol



The Meat gauge indicates about 106-108F comparing a true temperature registered of 110F... LOL

We all gotta love what MacGyver taught us about use what you have available to use in a pinch, number one items , duck tape and bailing wire... LOL