99 Mustang overheating but no heat

[claytonisbob]

My ex-girlfriend called me and she said her car ('99 v6 Mustang) overheated after 10 minutes or so going to work this morning (its really cold out btw). She parked it for 5 minutes and started it back up and the gauge showed in the middle so she took off and it didn’t get hot after that.



About a month ago her belt tensioner pulley broke so I replaced it and the belt. About that time the heater evidently stopped working too. It was working a couple days before the tensioner went out I know. When the tensioner pully broke her car overheated a bit, but she parked it pretty quickly after the belt went because she lost power steering. When I fixed it, it started up fine and didn’t show signs of overheating to the point of breaking something (no smoke or vapor in the exhaust, plenty of water, she said it never steamed from under the hood, no unusual sounds, ect).

Now I’m trying to figure out if the heater going out and the car overheating today are related. The car has plenty of water, it never has been low. If the heater is just not working because of the blower motor, it’s a heck of a coincidence. I really don't care about fixing her heater... she just needs to get to work. The care has almost 200k on the odometer btw. I was thinking it could be the thermostat hung and caused the overheating this morning, when she parked it opened up. She has no warning lights on though.

Any ideas? Thanks in advance.

[paul67]

It might need flushing out, use a hose pipe ,sometimes if yjr yemp is not moving it's because is sitting by the sender.

[kamaroman68]

Let her new boyfriend figure it out!!!! Just kidding. Chris

[claytonisbob]

Let her new boyfriend figure it out!!!! Just kidding. Chris

You have no idea how much I feel this way, but what do I do... she drives a pos and I feel bad for her.

It might need flushing out, use a hose pipe ,sometimes if yjr yemp is not moving it's because is sitting by the sender.

Could deposits in her cooling system really be causing this? I'd say a flushing would be if it slowly started to overheat. This is all sudden.

[vanzuuk1]

Am I missing something or could a lack of antifreeze have the coolant freezing in some spots,causing it to overheat?

[paul67]

If it is slowly overheating it could due to heat transfer.

[claytonisbob]

I know it has plenty of antifreeze.

[Restomod]

I would say the thermostat is sticky.

[MonzaRacer]

flush with new thermosat and rad cap and 50/50 AF/Water.
If its still getting hot and no heat she needs to trade or have heads pulled for gasket replacement or possibly if cruddy coolant, could have ate all the fins off the wp impeller.

[jfryjfry]

when you say the heater isn't working, is the fan blowing or not? if it's not, then it's unrelated to the cooling system. if so, but it's blowing cold, then something's (obviously) amiss. but 2 completely different problems.

[MrQuick]

A heater blowing cold and overheating would indicate an air pocket in the system. May have happened at the time of the belt loss. Check to see if you may have accidently popped a vacuum hose loose. If I remember correctly the heater flow system runs off of engine vacuum.

Also a head gasket leak will put combustion gas into the system causing an air pocket. Which can also cause both problems you are having.

Try refiling the cooling system with one of the heater hoses off and fill the radiator till you get fluid at the heater hose/port. Then run through your system checks.