I recently purchased a 2004 Mustang GT 40th anniversary from a ty used car dealership. I have some mechanical background but am looking for advise and wisdom - always!
I noticed after driving the car now for around 200 miles that the temp gauge on fairly hot and humid days would rise up to around 3/4 of the way to H when the car was idling. I noticed that if I quickly get it up to 5th gear @ around 60+ MPH the gauge would lower back down to around normal operating temperature approx. 1/2 of the way to H.
The car recently got an oil change from Ford (I was told by used car dealership)... I checked the oil filter and it is in-fact, brandy new. The oil is still liquid gold as well.
So I checked all fluid levels and realized the coolant was slightly low. So I topped up the fluid. A few days later, same over-heating issue, and the coolant was perfectly full. (Which ended up burning off after heating up so much so I had to top-up again.)
I started to think it was a head gasket leak but...
I purchased a Radiator coolant pressure tester from my local harbor freight and to my surprise I left it for 15 minutes straight and the pressure never dropped. Pressure remained @ 15PSI until I dumped air or unscrewed cap. I retried to test several times for re-assurance.
So it couldn't be a head gasket?
-Oil is not milky
-Not coolant leak/pressure leak
Radiator has bent fins and it appears to have either taken a beating from a small accident or maybe several rocks 130k miles later.
Fan is perfectly functional. Seems to be always running while the A/C is on.
I just replaced Thermostat about 2 hours ago and went for test drive. No problems yet, but it's rather intermitted as is anyways.
Side note:
A/C get's warmer when car starts to heat up.
Could be air pockets in coolant system?
Could be radiator?
Could have been thermostat?
Could be wrong oil? (Definitely feels like 5W-20, although looks over-full on dipstick)
Could be intermittent fan wiring issue?
I noticed after driving the car now for around 200 miles that the temp gauge on fairly hot and humid days would rise up to around 3/4 of the way to H when the car was idling. I noticed that if I quickly get it up to 5th gear @ around 60+ MPH the gauge would lower back down to around normal operating temperature approx. 1/2 of the way to H.
The car recently got an oil change from Ford (I was told by used car dealership)... I checked the oil filter and it is in-fact, brandy new. The oil is still liquid gold as well.
So I checked all fluid levels and realized the coolant was slightly low. So I topped up the fluid. A few days later, same over-heating issue, and the coolant was perfectly full. (Which ended up burning off after heating up so much so I had to top-up again.)
I started to think it was a head gasket leak but...
I purchased a Radiator coolant pressure tester from my local harbor freight and to my surprise I left it for 15 minutes straight and the pressure never dropped. Pressure remained @ 15PSI until I dumped air or unscrewed cap. I retried to test several times for re-assurance.
So it couldn't be a head gasket?
-Oil is not milky
-Not coolant leak/pressure leak
Radiator has bent fins and it appears to have either taken a beating from a small accident or maybe several rocks 130k miles later.
Fan is perfectly functional. Seems to be always running while the A/C is on.
I just replaced Thermostat about 2 hours ago and went for test drive. No problems yet, but it's rather intermitted as is anyways.
Side note:
A/C get's warmer when car starts to heat up.
Could be air pockets in coolant system?
Could be radiator?
Could have been thermostat?
Could be wrong oil? (Definitely feels like 5W-20, although looks over-full on dipstick)
Could be intermittent fan wiring issue?