Bubble bubble toil and trouble??

[PaulC]

Went for a.spin in the beast today and the temp gauge stayed in the range of the one and zero of 190.
Got home and shut down the engine and the overflow bottle immediately started bubbling and gurgling. Also don't recall the fan being on before I shut down as I was tweaking the idle a bit and it wasn't running.
What gives? I've bled the cooling system several times and it seems there is no trapped air.

[SteinOnkel]

Go to your local friendly corporate parts dealer and borrow the radiator test kit. It takes all the guess work out of coolant system woes.

[18Fiatsandcounting]

In addition to Steiny's suggestion, I'll add my $0.02 worth (inflation adjusted, of course).

It sounds like your cooling system is marginal. It may not overheat while driving, but the temp shouldn't fluctuate that much when driving around. It should reach temp and stay there. Also, the fact that it immediately started gurgling in the expansion tank tells me that, when you stopped, the engine went into a hot soak and heated up the coolant enough to pressurize the system so that the radiator cap released the pressure into the expansion tank.

OK, now the challenge is to figure out why the cooling system is marginal, and I'd start with the fan. With the ignition on but the engine not running, the fan should come on if you short together the two wires leading to the fan thermo switch at the bottom of the radiator. If the fan doesn't come on, that's a good start to figuring out what's wrong.

-Bryan

[PaulC]

We will certainly try these suggestions, starting with the fan switch.
Need to add more coolant now too. The radiator is full but the flush tee is empty.

[Odoyle]

Can always have radiator cap tested, should have pressure rating on top of cap, think their suppose to be 11 or 13 lbs, or u can just replace it.

[18Fiatsandcounting]

If you get a new radiator cap, or if you inspect your old one, make sure that the coil and spring are the right height. I've seen a few radiator caps over the years that were just slightly too short, and so the seal wasn't pressed against the bottom lip inside the radiator fill tube the way it should be. The result was that coolant was pushed into the expansion tank when there was no need, and air was then sucked back into the radiator as it cooled.

Also, make sure your expansion tank is filled enough so that the coolant covers that tube in the center of the tank. If it's not, air could be sucked back into the radiator.

-Bryan

[baltobernie]

Your operating temps are in the correct range. If the fan thermostat wasn't working, you'd see numbers way above the "0" when stopped at a red signal.
Bubbling and gurgling suggests there is still some air in the system. It may resolve itself. If your coolant level when cold hasn't moved, you're good.
At a constant MPH and RPM, the needle doesn't move much. But in normal driving, it does; unlike a modern car.
Remember to open the heater valve to max occasionally when driving. I try to remember once a month or so. In addition to ensuring good mix of coolant, it is also a quick test of the temp gauge and sender - the coolant temperature drops noticeably and quickly when the heater is opened.

[PaulC]

Update
Went for a spin after refilling and burping the cooling system. All's well now, or at least there's no overheating.
The temp gauge hovers around the 1 of the 190 steadily, slightly higher at a light stop.
However, the fan doesn't seem to come on but there's no signs of overheating.
Just a very efficient cooling system? Air temp was mid 50s.

[18Fiatsandcounting]

Sounds pretty normal to me. My fan doesn't come at all unless it's either a hot day (over 80) stuck in traffic, or a long uphill climb or the like.

I think you're good to go. Can't hurt to keep an eye on it, of course.

-Bryan

[PaulC]

Finally, success! Just in time to ship to Maine and put it away for the winter.
At least the new house has a separate detached oversized garage that's even heated

[redcars]

If you want to test the fan just let it set and idle and even with the cool weather the fan will come on after while. Just watch your temp gauge and you will get your answer. I am glad you got your cooling system working again.