Car Running Hot

[OWhatAThrill]

Hello all,
Haven't posted here before but if you are anything like the maxima.org group, I've come to the right place and I hope I picked the correct area. Saw the word coolant and after today, we realize it's part of the problem and we're hoping it's not the radiator.

History:
We've got a 1999 black convertible Cobra. Car has been running hot. We first noticed with air conditioner on but yesterday it stayed at normal temp with air on. I drove it the other day, before I pulled off, we noticed it was low on antifreeze and water in the radiator so we topped it off. I made two short stops, didn't turn on the air, no issues. I then drive across Nashville which took about 20 minutes and made another stop. Air still off, car temp still fine.

Then I drive to our small city about 30 minutes out of town. No issues. I then drove through our small downtown where there are 3 red lights. I decided to turn the air on and see what happened, since I was a mile from home. Made a stop and when coming back, got caught at two red lights and I noticed the temp gauge had finally moved to about the 3/4 of a way to hot, whereas it had been on the temp icon for the previous time. I had put the air on Max because I wanted to test it. When I noticed it running hot, I turned off the air and turned on the heat, as I've always heard that might help cool it back off. Not sure if it would have helped because I then arrived home.

So yesterday, he checks everything and noticed it needed more coolant, so he went and got some "STOP LEAK" to put in it. Lets the car run in the driveway with the air on. Ran it for 30 minutes, temp gauge never moved off the temp icon, and then he drove into Nashville, no issues.

Came down today and after he let it cool, he checked the coolant. LOW and needing some. He had first thought the fan wasn't kicking on but it is but he feels it's not running as fast as it used too, but this could just be a bad memory.

Sounds like a radiator leak somewhere to us. Anyone else have this problem and are there any tricks tips to finding the leak ourselves before we take it to our regular mechanic. We've just shelled out some cash on this car and the Max for some normal expensive repairs and are hoping we aren't looking at a new radiator. Any thoughts? Is the behavior of when it's cool and when it runs hot indicative of problems you have had in the past? Would appreciate them! Thanks!

 

[P49Y-CY]

one of the key things to remember with these four-valve motors is to make sure the coolant crossover tube is always full. usually you don't need to check that, but in this situation with you needing to add coolant as you describe, I would make sure that the crossover tube is full, and then go from there.

reason I mention this is because I see not mention of the crossover tube anywhere in your post. unless using a vacuum fluid exchanger, these engines must be filled from the crossover tube, not the coolant reservoir. (they can be "topped off" at the reservoir, but only so long as the crossover tube is already full.)

 

[OWhatAThrill]

one of the key things to remember with these four-valve motors is to make sure the coolant crossover tube is always full. usually you don't need to check that, but in this situation with you needing to add coolant as you describe, I would make sure that the crossover tube is full, and then go from there.

reason I mention this is because I see not mention of the crossover tube anywhere in your post. unless using a vacuum fluid exchanger, these engines must be filled from the crossover tube, not the coolant reservoir. (they can be "topped off" at the reservoir, but only so long as the crossover tube is already full.)

I haven't heard a word about him checking that, he's just watching the reservoir. I will mention this to him tomorrow as he's away for the evening. I'll go look as soon as I get a chance also because the car is here. Do I check the tube while the car is cold and off, or should I start it first? Thanks for your reply!!!

 

[03dsgcobranc]

http://reischeperformance.com/refill

 

[OWhatAThrill]

http://reischeperformance.com/refill

THANK YOU! After reading that, he's decided to take it to his mechanic. He's got PTSD which is affecting his motivation, and no, we've only been adding it to the radiator, and when I was talking about it's a closed system with vacuum seal, he said he'd take it to the guy who works on it for him. He's got two back window problems anyway, the driver side back window won't go down until you play with the switch for awhile which is obviously sounds like a button panel problem and the passengers side back window won't row up all the way, it will roll up 3/4 and stop and you have to pull it up the rest of the way, and that's been affecting our driving it with the top down, so he's been meaning to take it anyway.

Could something as small as not putting in the coolant correctly make it run hot? Could the problem really be that minor? We'd like to hope so!