After installing the 307 in my 1983 Delta 88 sedan, its running well but the cooling system doesn't seem to be circulating. The radiator hoses get super rock hard like they are about to burst and the coolant reservoir level doesn't move. I put a new thermostat and water pump on the engine and the radiator is also new. A friend of mine suggested removing the thermostat temporarily to see if it'll circulate. I'd also considered perhaps an air bubble or a blockage in the system. Could it be coolant temp sensor?
Definitely open to ideas!

 

The upper radiator hose is supposed to get hard when the engine is running. Have you just idled the car in the driveway or have you taken it for a test drive yet?

 

Yes, I took it out for a 3-4 mile ride and it seemed to do okay. No engine warning lights etc. I'm curious why the coolant isn't going back into the reservoir though that is the main red flag. The coolant level is always just below the the hose that goes back to the radiator from the coolant tank.

 

It may just need more coolant.

 

I will definitely add some more coolant to it, may leave the cap off the radiator to see if itll burp itself too just in case

 

Parking with the car nose up and the cap off will increase the chances of it burping. Honestly I've never had much trouble with air pockets in those cars.

50/50 coolant to water when adding, excess coolant reduces efficiency, use just enough coolant for freeze and corrosion protection.

 

Very good thanks for the tip on the parking angle. Gonna try that and add some coolant to the reservoir and see what happens. Got this car in November, replaced the engine, and now the transmission lost reverse gear. I just want to take it home without it exploding LOL

 

It could be the cap as well. My 70 will feed into the reservoir but won't pull back out. It is an aftermarket stainless one. I have tried multiple caps with no luck. That level is fine for cooling but with the right cap and everything sealed should pull in and out of reservoir. Make sure the line and outlet on the overflow are clear.

 

First, the coolant level in the overflow tank ISN'T supposed to change when the engine is running. It only gets sucked back into the radiator after the engine cools off and ONLY if the level is low to start with. That tank isn't part of the circulating flow of coolant.
Second, if your cooling system wasn't "circulating", your engine would be locked up by now. It's fine. Everything you've described is perfectly normal. The hoses are SUPPOSED to get hard - the system is at 16psi when it gets hot. If the car isn't overheating, you don't have a problem. Stop fabricating one.

 

^^THIS! x100^^

Coolant, if ANY, will NOT get sucked back into the system from the reservoir until a vacuum is created. That vacuum will ONLY be created when the system (under pressure @ 16 psi) cools. As Joe stated, the coolant reservoir tank is NOT a circulating tank.

 

Check the coolant level in the reservoir when it is hot and then again when it is cold. The one in my Wife's Rivera rarely moves but maybe 1/4" or so.

 

Thanks for the advice everyone, I am going to leave it alone for now. I really appreciate everyone chiming in and helping me out! Most of my paranoia is because of this used 307 I put in. Gonna just let it go and get some miles on it!!