Moderate overheating condition

[Jessidog]

My daughter has a 2003 5-speed V-6 Mustang with about 60K miles. About a week or so ago, she noticed that the temperature gauge started to move slowly to the right when she started moving faster, especially above 30 mph or so. If she is driving slowly in stop and go traffic, the gauge stays in its normal position, but she can hear the electric fan turn on when it normally would not. Her boyfriend changed the thermostat with no effect.

I will be visiting her tomorrow so I have not had access to the car myself. It sounds like either a problem with flow through the radiator or possibly the water pump. She says there are no signs of a leak or unusual sounds. Therefore, I'm more inclined toward the radiator although I have heard of cases where the impeller comes loose.

I flushed the system throughly and filled with Preston Extended Life coolant about 2 1/2 years ago. Do you think one of the heavy duty flushes would be useful or would it be better to replace the radiator?

Thnak you in advance for your comments.

Jessidog

 

[Skymarshal]

You could have an air bubble in the coolant system if you didn't purge it correctly when you refilled it. If that's not it, the symptoms sound a little like a blown head gasket...

 

[Jessidog]

I replaced the radiator. Externally the radiator looked fine and there were no signs of a leak, but there must have been internal blockage of the passageways. It's only been about 2 days, but the temperature gauge stays in its normal position, just barely left of vertical.

Jessidog

 

[sixguns]

Hello from OZ

Hello from Australia,

I recently purchased my first Mustang, being a 1995 V6 coupe.

I seem to be experiencing a similar problem, although when I filled the radiator with some extra fluid it seemed OK for a day.

The next day the the same thing would happen, my heat guage would slowly rise to the red. I checked under the bonnet and the radiator and hoses showed no leaks, but the overflow system seemed almost full ?

Could it just be a dodgy radiator cap losing fluid under pressure or is the overflow supposed to be full as well as the radiator ?

Any help would be great as I don't want to cook the engine as parts hear are rare as kangaroo feathers.

Thanks and G'Day.............

 

[robb15033]

Both issues- When filling the system with coolant you want the vent plug unthreaded and occasionally squeeze the upper hose to vent any air. With the car running, fluid should be added until it flows out of the vent plug hole. It also sounds as simple as a bad Thermostat. With the original stock thermostats you will notice a small hole drilled and placed around the outer edge of the stat. This hole has to be added if aftermarket and when reinstalling, the hole lines up twelve o'clock while standing directly infront of the car bumper. It's there to relieve pressure.
Hope thats some kind of useful info to ya.

 

[redhot96stang]

same issues

i have a 1996 v6 i have repaced the thermostat and flushed the radiator. I have a slight overheating still but doesnt do it all the time. there is a white know with a bolt in the middle that says remove before refilling what is that for and could that be my car having air bubble. i really need some help fast before i freak out. should i replace the thermostat or wht please tell me what to do.

 

[zachdubois2]

sorry, can't figure out how to post my own thread! anybody help?