New radiator and thermostat issue

[WadiaAbushanab]

Hello everyone I have a 1980 Fiat spider. I just installed a new aluminum Radiator and new thermostat I got from Autoricambi but I’m having some trouble. The thermostat climbs very quickly. Up to 190 or 210 within minutes of the car running. The old one didn’t do that. And I don’t think the radiator is circulating as the top gets hot but the bottom doesn’t. I don’t have the t tube at the top to fill with coolant so I had to open the bleeder screw and then fill the radiator until coolant came out the screw. Would there still be air in the system? And why is the thermostat getting so hot?

[Nut124]

Are you sure u installed the thermostat in the correct orientation? Different makes may appera externally similar but the internal function may not be the same. Need to carefully examine the ports and install it correctly.

Do you have a floor jack? Jack up the front when filling the system.

[WadiaAbushanab]

Are you sure u installed the thermostat in the correct orientation? Different makes may appera externally similar but the internal function may not be the same. Need to carefully examine the ports and install it correctly.

Do you have a floor jack? Jack up the front when filling the system.

I looked at pictures and my thermostat looks right. I do have a jack but no jack stands so I won’t be able to keep it level. Or is there a place up front in the middle I can jack it up? Not on the sides.

[Anbele]

You can put a wood block (piece of 2x4) in the middle of the frame, under the engine, right next to the oil pan. But NOT on the oil pan. The car does not have to be level. The point is to make the radiator the highest point in the car so the air trapped in the coolant loop will travel towards the top of the radiator and escape. Massage the hoses while the water is circulating. Of course, all of these is with engine running and reaching normal operating temperature so the thermostat will open.

[WadiaAbushanab]

You can put a wood block (piece of 2x4) in the middle of the frame, under the engine, right next to the oil pan. But NOT on the oil pan. The car does not have to be level. The point is to make the radiator the highest point in the car so the air trapped in the coolant loop will travel towards the top of the radiator and escape. Massage the hoses while the water is circulating. Of course, all of these is with engine running and reaching normal operating temperature so the thermostat will open.

Ok sounds good. So I am supposed to have the engine on while filling and massaging tubes and stuff?

[Anbele]

Correct. Yes. You do.

[Nut124]

Are you sure u installed the thermostat in the correct orientation? Different makes may appera externally similar but the internal function may not be the same. Need to carefully examine the ports and install it correctly.

Do you have a floor jack? Jack up the front when filling the system.

I looked at pictures and my thermostat looks right. I do have a jack but no jack stands so I won’t be able to keep it level. Or is there a place up front in the middle I can jack it up? Not on the sides.

What pictures? Thermostats from different mfgs may look similar but do have different porting inside. Need to examine the ports for correct orientation.

Get a Harbor Freight alu jack or similar. Jack up on the front cross member making sure not to jack up on the oil pan. The bigger jack have higher lift, which is handy.

[Bagneaux]

I bought my aluminium radiator and thermostat from AR too. I installed the thermostat wrong until I read the last line in the thermostat description on the website.

Thermostat Tip: the port which will not pass air attaches to the lower radiator hose

That tip solved everything.

[WadiaAbushanab]

I bought my aluminium radiator and thermostat from AR too. I installed the thermostat wrong until I read the last line in the thermostat description on the website.

Thermostat Tip: the port which will not pass air attaches to the lower radiator hose

That tip solved everything.

I have the port that does not pass air to the bottom radiator hose. I even drilled a small hole to alleviate some of the pressure to help it open as suggested by many. Still seems like it’s not opening. I wired up a switch to my fan and cut the sensor on the bottom of the radiator off. Everything still worked normally until I got this new radiator and thermostat. Is this sensor needed to make the thermostat open? If so, why all of a sudden with the new one and not old?

[Barjavel]

I recently installed the AR thermostat and a new AR radiator. Or rather the shop did--an experienced mechanic who has worked on a lot of old cars (mostly air-cooled VWs, but also lots of other stuff) and who used to own Fiats 40 years ago.

Even *he* installed the AR unit backwards. He said, "why in the world wouldn't they put an arrow or something on the thermostat?". I don't know if that's a good reaction or not, but the backwards install apparently gets lots of people, even experienced mechanics.

The problem was evident within four miles of driving, the temps just kept rising. One clue was that the radiator fan wasn't turning on. That's because the coolant in the radiator wasn't circulating!

I think he was kind of embarrassed when we figured out the problem. Once he turned the unit around, it was no problem to bleed it.

[barnesjtsl]

Take the thermostat out and boil it on the stove in a pan and see if it opens.