1982 Classic with 454 Engine Question

[cesalie2]

My best friend Dudley has a 1982 Airstream 310 with a chevy 454 engine. Currently his water temperature runs about 218 degrees. Note: in comparison our 310 runs about 180 degrees.

So, here is his question...if he removes the thermostat...will his gas mileage decrease, increase, or remain the same?

Inquiring minds would like to know!

Thank you,

Daniel

[Naper]

Removing the thermostat will not improve the mileage if anything it will take longer for the engine to warm up using more gas.
Thermostat ratings are for the lowest temp not highest. In other words a 180 thermostat will allow the engine to run warmer than 180 but not colder.

[Steve Bryant]

I suspect that his temp should be regulating somewhere between 180 and 200 even with a thermostat installed. I would say that he has one or more of the following problems:
1. Thermostat is sticking partially closed (insufficient coolant flow).
2. Radiator is getting plugged up (inadequate heat exchange in radiator).
3. Fan clutch or shroud are defective (insufficient air through radiator).
4. Temperature indicating system is inaccurate.
5. Coolant level is low (insufficient coolant).

I've tried to list these in the order of most likely to least likely. Low coolant level is really a prime candidate, but I assume that this has already been checked.

It's not a good idea to run an engine without a thermostat except for a short period (like to test the thermostat) but that can be done more easily by sticking the thermostat in a pot of water on the stove with a thermometer in the water. That way you can watch the thermostat open at its approximate design open temp (stamped on the thermostat). If I removed the thermostat and it was very old at all, I'd just stick a new one in it with a new gasket and call it good.

The reason one shouldn't run without a thermostat is that the engine is efficient and runs with the least friction at its design regulated temperature. Running too hot is no good, because it shortens engine life, reduces power, can cause vapor lock in a carbureted engine like this one, can cause detonation, etc.

BTW, I would probably run a 180 degree thermostat in this engine.

Steve

[ROBERT CROSS]

Dan,

All things being equal, remain the same.

What advantage removing the 'stat?.....none Check and replace if needed. (stainless, if you can find one)

The quicker the engine warms on a cold start the better.

Back flush & flow check the cooling system.

Bob

[cesalie2]

All,


Many thanks for your timely responses.

Dudley is concerned as we are planning a 5 day trip next month...

Daniel

[cwf]

The opening temp should be stamped on the tstat.

Get a pot with enough water to submerge tstat and a candy thermometer.

Heat water to "open" temp. Drop tstat in. Within seconds you should see the tstat valve open. If it doesn't, it's defective.

Use same process to verify NEW one works at stamped value.

If tstat opening at 180 as it should, problem is elsewhere and should be fixed before trip, or... You may mess up motor.

[bwoodtx]

In addition to everything noted above, removing the thermostat will actually make the engine run hotter. This because by removing the t-stat you do not allow the coolant to cool through the radiator. With a good, clean system and a 50/50 coolant mixture and the proper pressure cap you should have a 15-20 degree drop in temp from the top hose to the bottom hose. This can easily be checked with an infrared temp gun. BTW are you sure the gauge is accurate?

[garry]

It may even run hotter, without a thermostat. Even at wide open the thermostat slows the fluid flow through the radiator allowing better cooling.

If he has an AC it could be trash between the engine radiator and the AC condenser.

[cwf]

Check for bad airflow too. Just like Garry says. Saw a pickup that had a mass of straw between radiator and condenser. Nearly no airflow. He had "tried everything". Also found the fan was not working right as the clutch failed.

We replaced with electric fan. Gave better AC function and ten drop if coolant thru the radiator.

Good luck!!!

[Robfike]

I believe all of our Classics should be running the 195 degree stat.

[cesalie2]

Dudley followed the forum advice and measured the temp with the temp gun...195 degrees. Gauge read 220.

He said he would change the temp sensor first and measure again.

Thanks to all the forum contributors!

[cwf]

Yeee haw!

[DaveFL]

I changed my sensor got same reading, checked thermostat works, now I know gauge is wrong so don't worry about it, if it moves up then I will know I have problems. lol