Overheats again!!!

[Felix_29]

Hello all, almost a year ago exactly my car overheated. the culprit was a bad thermostat that was stuck closed. A new thermostat plus a coolant flush and replace I have had no heat issues since. Until today.

It was a hot and humid day here in Ontario not that I think that should matter as I drove my car in the day. I noticed my coolant temp gauge will creep up to half way if I am not moving. And I did have the car turned on for a bit before I started to drive away. I think it has to do with not getting any air flow someone correct me here if i'm wrong. As I start to drive the guage should go down to about 1/4 where it usually rests when the engine is at normal operating temperature. But I noticed as soon as I was able to drive away from my red light my engine temperature gauge pegged out to the top and I looked behind me and there was no smoke coming from my coolant bottle. And the guage all of a sudden went down to half and later as I continued to drive back down to 1/4. And later it did it again but only jumped to half way and eventually I lost my a/c for a couple minutes at another point and then it came back on blowing ice cubes as normal.

Tonight I take the car out again. And I am having similar problems with the guage where it jumps to a 1/3 and then back down to a 1/4 at the beginning of my drive and the car was fine for a long time and eventually I was stuck in traffic and my guage creeped up to 3/4 and I had overheating I had the bad smoke coming from my overflow tank. So in a couple minutes I was able to pull off to the side of the road and shut her down and I had the car towed back to my house. Any idea's on what's happening?

[congerz83]

Did the fans ever turn on? If they did, it could be a couple of things. There could be air in the system that you can fix yourself with a small wrench. The valve is on the thermostat neck. The cap itself could also be bad. Those are the first areas to check. But first make sure those fans are switching on..

[Bitsyncmaster]

Did the fans ever turn on? If they did, it could be a couple of things. There could be air in the system that you can fix yourself with a small wrench. The valve is on the thermostat neck. The cap itself could also be bad. Those are the first areas to check. But first make sure those fans are switching on..

+1

Sounds like the fans are not working.

[Felix_29]

Where do I find the thermostat on the car?

[Jonathan]

How do your belts look Felix? And specifically going around the water pump?

I'd also agree it sounds though like your fans aren't coming on and the cooling you are getting is only from the wind while out on the highway.

The coolant temp sensor is located just under about the spot where your oil dipstick goes. The sensor is teed into a horizontal coolant pipe. It could point up or down, but ideally should point down. A good test for your fans is to jumper the leads going to the sensor to trick the car into thinking the coolant is above the set point. If your fans don't come on while this is jumpered, you need to start troubleshooting why on this problem first. I had a similar issue on my car when I first got it so hopefully we can help you find your culprit.

[Felix_29]

My belts look good, good tension. My cooling fan failure light didn't come on though. Sometimes when I drive I get a small whistling sound coming from the engine bay and it will go away once I reach my certain speed. its kinda high pitched. Could that be a belt of a vacum leak of some kind. Could that be introducing air into the system.?

[Ron]

Where do I find the thermostat on the car?

Thermostat #4 HERE (http://store.delorean.com/c-270-1-3-0-water-pump.aspx).
Thermostat Switch/Otterstat #65 HERE (http://store.delorean.com/c-332-1-3-2-piping-to-waterpump.aspx).
Temperature Switch/Temperature Sensor #45 HERE (http://store.delorean.com/c-330-1-1-5-cylinder-headvalvetrain.aspx).

+1 on all of the above suggestions.

Both belt and vacuum leak can give a high pitched sound...either could be related, but neither would introduce air into the cooling system....

[Bitsyncmaster]

My belts look good, good tension. My cooling fan failure light didn't come on though. Sometimes when I drive I get a small whistling sound coming from the engine bay and it will go away once I reach my certain speed. its kinda high pitched. Could that be a belt of a vacum leak of some kind. Could that be introducing air into the system.?

Do you still have the OEM fan fail unit installed? Blue "relay", left most postion in relay compartment. You should have jumpers replacing that unit.

With the jumpers, you would not get a fan fail light ever.

The whistle is most likly a vaccum leak on the "W" pipe. Try to tighten up the four bolts to stop it but don't break a bolt.

[stevedmc]

+1

Sounds like the fans are not working.

I love my 65 Mustang. The fan is powered directly from the motor.