383 Roadrunner cooling TOO well.

[The Beep]

So here goes. A couple of years back my 383 was overheating. So I installed a high flow water pump and housing, flushed the stock rad etc. Still overheated. Turns out the upper rad hose was collapsing (bad spring in hose). Ran good after that was fixed.

So here is my problem now. Here in Canada a hot summer day is 80 degrees. With a 195 stat the car runs strong all day around 200 (verified with stock gauge, aftermarket mechanical and infrared). At night it's another story though. The temp here yesterday went from 85 to 50 once the sun went down. As soon as the stat opened BOOM the temp dropped to about 150 on the highway. Ran like poop! The friggin choke even kicked in!

Suggestions?

 

[Photon440]

If your 195 stat lets the temp drop that low, it's not closing and shutting off the flow.

 

[The Beep]

I agree but shouldn't it be the same regardless of wether its hot or cold out?

 

[bm02tj]

It is not completely closing so replace it and before you install new one look to see if light comes through the sealing surface

Bruce

 

[brasil]

x2 I would replace the thermostat ....

Greetings Juergen

 

[The Beep]

New stat it is! I will let you know how it works out. Had to order one, 4 parts stores here and nobody stocks one. Argh.

 

[Moparsmitty]

I always check a new thermostat in a pan of hot water on the stove to make sure that it operates properly at the advertised temperature. Seems like the quality of all of the tstats has fallen off in the past several years. All the shops that I sold parts to were complaining about them. It didn't seem to matter where you got them. Even the premium ones aren't that good anymore. A few months ago I tested a brand new Mr. Gasket 180f stat That didn't open until the water was over 200f.

 

[Dennis H]

NAPA 180 Superstat. Ambient has a lot to do with engine temp.

 

[The Beep]

Yep, new stat fixed it!

 

[Photon440]

Yep, new stat fixed it!

Glad to hear it. Nice when a problem doesn't get too complicated. Still some summer cruising time left.

 

[The Beep]

Just an update from the first post. Replaced the stat (new 180 deg) and car seems to maintain the same temperature. I have both a mechanical and stock electrical gauge. Mech reads 200 however stock dash gauge reads right on the bottom of the "normal" range. Rest of my gauges seem right.

My question is, does this appear to be the right place on the stock gauge?

 

[Lowhound]

They can stick in the open position just like they can stick closed. Its just we don't notice because its not too dangerous of a problem as running hot.