97 Cobra Running Hot

[tarponboy]

Hi everyone,

I have a 97 Cobra with 102,xxx miles on it.
Bought it about 1 year ago.
Only driven occassionally, on the weekends.
When I bought the car, it had a very slow drip of antifreeze from the lower thermostat housing.
No problem, took the car on around town trips and all was well (just a few drops of liquid at end of trip).
One day, the seal between the lower thermostat housing components blew and I lost all the antifreeze.
After being a new housing and thermostat, I filled up the radiator with new PEAK pre-diluted 50/50 mixture.
I know the car can take 5-6 gallons or so, so as I got to almost that amount, the upper radiator seemed full, so I stopped putting in more coolant.
No low coolant light, all seems well, but... the car runs hot.
What I mean by that is using the SCT programmer I have (it has built in engine sensor reporting capabilities), I can see the coolant temperature runs between 200-230 degrees (varying in that range over the course of a 50 mile drive, never staying high or low... just varying.
This temperature is confirmed by the stock engine temperature gauge in the dash cluster (regularly showing the needle at or just above the "L" in the word "NORMAL".

So I started thinking... what is the new thermostat I put in the new housing was not opening?
If it weren't, wouldn't the car run well above 230?
Is the coolant not full? There is no room to put any more coolant into the upper radiator reservoir and there is no low coolant light on any more.

I figure this must have something to do with the replacement of the lower thermostat housing and thermostat and coolant filling.

That being said, I guess it could just be a coincidence and perhaps the upper thermostat is the problem.

What do you guys think?

 

[Mattstang04]

They're is a special shirt bleeding procedure for 4 valve engines. I dint know exactly what it is but it can cause air bubbles to remain in the system and run hot if not done when filling up the coolant. Search on the procedure. It's likely the problem.

 

[tarponboy]

They're is a special shirt bleeding procedure for 4 valve engines. I dint know exactly what it is but it can cause air bubbles to remain in the system and run hot if not done when filling up the coolant. Search on the procedure. It's likely the problem.

What a gem. Thank you much. You just might be right...

https://www.stangnet.com/mustang-fo...ing-system-after-flush-very-important.628582/

 

[tarponboy]

Hmm. I am a bit puzzled. I run the car up to 190 degrees with the cap off, but did not see any fluid come out. I would know as I had white towels all around the opening that were dry. So then I held the RPM at about 2,000 for a bit, with same result. I then revved the engine to about 3,000 RPM and saw some coolant bubble out. I did that four or five times and then looked into the reservoir, but there was no obvious lowering of the coolant (it was still pretty much near the top). Not sure what to do next.