Ok so I am having a cooling problem and I will not drive my car now. I've been having a problem where it pegs at H as soon as I start moving after waiting at a light. Well I replaced the thermostat today thinking that may be the problem, but didn't work. Another person mentioned maybe it being my hoses closing, so I clipped the ends that were a little long and that didn't help. My hoses have wire through them so its hard for them to close up. What's going on here? I've noticed a major power loss since this has started.

It is also worse with the new thermostat, I went from a 160 to 195.

 

The new thermostat is probably set to 195, it should say right on the unit (I always buy failsafe and they have it on there).

But I dont get what is wrong with it running 160 before, thats cool IMHO, what should it be running at?

But if you think its running hotter than before (based on your experience and history with it), you only have 2 other components - the pump and the radiator.

So:

1) Is the radiator flowing well? Pull the cap and watch it flow (while cool). What about at the bottom? Try running it with the bottom hose off (when cool) it should be flowing out fast, not trickling out...

2) Any leaks at the water pump? If the thermo is good, and the radiator is good (or if the flow is bad), you will probably need to pull the water pump and inspect its play inside - lots of play means it isnt propelling the water fast enough.

If you change over all 3 of those components and you still have heat problems, then you need to go to Harbor Freight and get you a infrared temp gauge (29.99 and you can use your 20% off coupon), to check block temperatures. If it cooler or warmer in the front or back when at temperature, there may be blockage in the block.

The temp gauge is a good idea no matter what when trying to troubleshoot cooling problems.

 

Those are the thermostat temps not the running temps, I should have been more specific. I had a failsafe to install but read how bad they were and returned it. The radiator is about a month old and its an aluminum 2 row big block radiator. This is my 2nd 302, but I never was able to watch the temp on my first because it blew up in 1 week. No leaks at the water pump.

It has always ran warm, even after swapping my I6 radiator over to the bigger one. It has just recently acquired the heat up problem. It will start off fine and then the temp needle will move to the middle of the gauge. Then I will be sitting at a stop light and it won't move. But as soon as I start moving again, the needle pegs at Hot.

 

I will politely differ with you on the failsafe, I had one "fail" on me on my 05 Silverado and it did the right thing, it opened up all the way.

With the water pump, it could still be hosed up. I had my 73 Eldo (before I traded it a few months ago) with good flow on the radiator, need a new pump.

The only way to figure it out was to pull it - the propellor was wobbly, it wasn't spinning right if at all.

 

Well I heard they worked, except they would fail during normal driving conditions.

This engine probably has around 100,000 miles on it and as far as I know nothing has been replaced on it. So I wouldn't be surprised if its messed up.

 

Well it seems my fan quit working, drove to my grandmas like that and it never got over half way on the gauge.

 

Cool, that won't cost you too much, and you know what it is!

 

Well then driving home it decided to go past H on my gauge. It was random too, just took a turn and while driving it went all the way. Didn't do it for majority of the drive back.

 

is the belt slipping? Could be that the fan is showing down or not spinning at all. Maybe its not tensioned correctly.

 

I'm running an electric fan, I have a mark 8 fan on the way though. I think there might be crap in the water passages it something.