More cooling system questions UPDATE

[majicwrench]

"If it's running full time car should run cool, right?" WRONG coolant still needs to circulate. I'm not going to bother asking you again if your radiator gets hot.

Really can't overpressurize. You radiator cap should release excess pressure---into overflow bottle. If bottle level goes up three inches!!! then your radiator must be low on coolant, correct?? If so, something is pushing the coolant out. LIke combustion gasses getting into cooling system.

Certianly could have a bad head gasket. Can buy a test kit at NAPA, bottle of blue fluid. Turns yellow when it exhaust gasses pass thru it.
Best of luck to you.

[4uall]

TENSION BREAKER

https://www.youtube.com/watch?v=kq-VNCGBDRU

work safe, need sound

CRANK IT

[georgeramos]

Thanks man

[georgeramos]

Im not at home to check if rad gets hot but will check it next time. I know it gets hot at the top but havent checked bottom in a while. I understand coolant needs to flow and the running fan alone wont keep the car cool but what i mean is that havong the running fan full time will not create overheat issues so i wired it to rule it out for the time being. I see that the proper operation would tell me whether or not the bottom of the radiator was getting hot and would answer that question. It wasnt befote and when i pulled the old stat and boiled it i found out why. I need to verify that the new stat is working. Got it. Sorry all.

[bradartigue]

Im not at home to check if rad gets hot but will check it next time. I know it gets hot at the top but havent checked bottom in a while. I understand coolant needs to flow and the running fan alone wont keep the car cool but what i mean is that havong the running fan full time will not create overheat issues so i wired it to rule it out for the time being. I see that the proper operation would tell me whether or not the bottom of the radiator was getting hot and would answer that question. It wasnt befote and when i pulled the old stat and boiled it i found out why. I need to verify that the new stat is working. Got it. Sorry all.

I wouldn't apologize to anyone here. Old cars are frustrating. I've rebuilt engines before because they wouldn't start and I tried everything else out (and it ended up being something like a bad coil wire). Maddening work.

Pull the plugs, check 'em, do a compression test, see if the head gasket is bad. Another method - drain the oil. If water is getting into your block it will show up in the oil. Another method - check the vapor hose. If it has liquid coming up when running, you're definitely leaking inside the chambers.

If none of that does it then I'd try to figure out if that radiator is blocked with something. If your heater core was leaking then it was also disintegrating - into your cooling system.

[georgeramos]

If you drain the radiator and remove the bottom hose, and put a garden hose in the top, it should flow out as fast as its flowing in. Then if you put on the bottom hose and take the thermostat off it should all leak out when the hose is running. With all of the hoses on and the block plug removed it should pee out of there, and with the block plug in and the T removed it should flow out of there. And it should really flow, like annoyingly too much, fill up your spark plug holes kind of flow

OK, I was going through these steps. First one seemed to flow out with ease although I had the hose on pretty high pressure setting so it sprayed a bit at the top and of course out of the overflow nipple. Then I tool the thermostat hose (from the water pump side) off and it gushed out of there. Also out of the petcock. As I was doing this I removed the thermostat to drill a hole in it and it looks like this



Does this look right? it looks like it's "open' a bit, is this it's normal position? this is a NEW thermostat thats only been in a couple of weeks if that. If this is correct where do i drill the hole? If it is not correct could it have been "too much pressure" that would cause it to fail immediately? Actually i know the answer is that this thermostat is stuck open.

Also Brad when you refer to the 'T" do you mean the hoses at the T in front of the timing cover?

The radiator cap is new, a fiat type from AR. The other day when it ran well was the first drive with that cap (of any distance) and the overflow bottle was fuller the next day if that is of any consequence. The previous cap was the typical Stant you can get at Autozone.

[4uall]

I am not of the belief that anyone needs to be drilling holes in these thermostats. But what the hell do I know.

[georgeramos]

Well I will have to wait for a new thermostat but as I flushed everything out i would say there is a slight possibility that the overflow hose was clogged although the coolant did all drain through it into the collector so it wasnt fully blocked. There was definitely a lot of crud in the bottle though so i flushed it out 10 times or so and it looks a bit better.

I'm still baffled by the overheating though and with the stat stuck partially open i'd think the car would take longer to get to temp.

Is there a way to test the water pump?

[bradartigue]

A few things:

- Get a stock FIAT radiator cap. I've had bad luck with aftermarket caps.

- If that thermostat is stuck slightly open then it may be stuck period, meaning that it takes a little longer to warm up, then it overheats (because it isn't opening enough). This may be 100% of the problem. When you replace it make absolutely sure it is oriented the correct way. And I've never drilled a thermostat to make the cooling system work, you shouldn't have to do anything of the sort. Drilling it may simply introduce something else to diagnose.

- The "flush and fill" T you removed really does help fill the system. I would put it back, install the new thermostat, fill the thing up (with water). The water pump can be tested by removing the cap on this thing and starting the car, water should come up and out.

[4uall]

This might help





You can clean your overflow container with hot water and coffee grounds (rinse thoroghly)

[georgeramos]

I will update as i learn more today. I need to rewire the fan circuit so it operates normally...

[georgeramos]

Havent rewired fan yet but decided to drive it after filling system to see where it was at. To answer Keiths question the upper radiator and hoses get hot but the lower no. Car still running too hot but doesnt get to red. Upper hoses get very hot but do not feel hard. They still feel pliable. Radiator seemed to flow through with the garden hose and as ive said is a recent recore so should I be thinking water pump? the pump was replaced about 1 1/2 years ago but it did start to show exterior corrosion after being in my friends damp garage last winter. The belt has about 1/4" of deflection. I havent tested water pump per Brads suggestion because i threw away the plastic Tee fitting and Id rather not put one back and allow another place for leaking. i instead bought one of those "no fill" funnel kits and it makes the radiator cap into a much higher point than the heater hose. As I ran the car i saw many bubbles escaping for about 2-4 minutes at about the time the thermostat should have opened. Then the liquid in the funnel dropped and the bubbles ceased as i ran the car for another 20 minutes or so. The car at idle stayed at proper temps but while driving climbed a bit.

I made sure the overflow hose was clear and I cleaned and re-cleaned the bottle. I could not remove the old temp sensor, need a longer socket wrench for more leverage but i am afraid to break it, is it OK to spray PB blast on there? While the funnel was attached and the car running, as the bubbles were escaping I could see some liquid flowing out creating a small 'plume" every now and then. it was not constant and once the bubbles stopped everything seemed to settle down.

If I rewire the fan I dont think it will kick on as the lower radiator is remaining cool.

Let it cool down a bit and pulled the cap to top it off, then started it again. Reached temp pretty quickly and i was waiting to see "flow" with the cap off but water started to rise and drip out instead. I made several short videos i can send if anyone can offer any clues by seeing that.

[seabeelt]

Having been through this, it can be and is frustrating for such a simple system.

My advice for what it is worth.....

Most of the cooling problems I have experienced are related eventually to burping.

That said, Forget everything you have done or think you know you have done and start from scratch.

Basics first. Disconnect the lower radiator hose and drain, then perform the garden hose test by sticking it down the fill neck. You might get some splash because of the hose pressure, but you really shouldn't be getting any water out of the top as the hose is 1/2" to 5/8" and the bottom radiator opening is much bigger than that. ...... If you are getting water out of the top, then I would take the rad to have it professionally checked as the hose test indicates a radiator restriction.

Next boil the thermostat, new or not...... Perform the test. You will know if it doesn't open properly. It should be open before the water boils....

Next, pull the hose off of the water pump. If you turn the pulley by hand or crank the engine, does water gush out. If it does and there are no visible leaks on or around the pump, chances are it's OK.

Reconnect everything, fill and burp, cycle the engine until it gets warm with the rad cap off until it gets ready to overflow out of the rad cap opening. You might need to do this several times. Keep refilling.

Side note, overflow bottle has a tube inside that has an opening at about half way up the bottle...... Very unlikely that you would get junk back into the cooling system unless it floats, or the tube is busted off at the base of the tank...

If you don't have one, get an infra red thermo gun. Best $20 you can spend.

Now with evidence that you have a working thermostat, and the radiator is not plugged, and that your water pump impeller is pushing water, and that you have most if not all air out of the system, put the radiator cap back on and test.

Without looking every 5 min at the temp gauge, check the upper and lower radiator hoses. Upper is hot first of course, then the bottom hose. You should get some expansion into the overflow tank (thermal expansion), but not a lot.

If you get a lot, re-burp, and re-test. Look for visible leaks....

Test the thermal switch in the bottom corner of the radiator with a meter. It should read open when cold and closed when hot on the resistance scale of a multimeter. Check that corner with the infra red gun. Switch should kick over from one to position to the other at about 185 give or take. AR sells one that flips at 160 I believe if you want it to come on sooner.

Check gauge, where is the temp


Constant theme here, test, test, test

If you are still getting excess overflow, then I would get the Napa kit and check for exhaust gas in the coolant. Easy to do, easy to read, painful if it changes to yellow.... Read change the head gasket.


Like I said, forget what you have done and start fresh, note your results from the tests and move on to the next component. More than likely it needs more burping

[azruss]

remember on your initial fill, there is a big air bubble in the bottom hose. It is trapped under the stat insulating it from heat. Until the stat opens, the air bubble doesnt go away. This is the purpose of drilling the hole in the stat valve. It allows the air to escape without the stat opening. This is a closed pressurized system that performs well as long as there is only liquid in the system.

[fiat218]

remember on your initial fill, there is a big air bubble in the bottom hose. It is trapped under the stat insulating it from heat. Until the stat opens, the air bubble doesnt go away. This is the purpose of drilling the hole in the stat valve. It allows the air to escape without the stat opening. This is a closed pressurized system that performs well as long as there is only liquid in the system.

Was there a factory holed drilled in any stat valve