OK, so this may be a stupid question, but here goes, the temp gauge in my ’49 cad (original 6v with a Runtz) quit working, so I thought I’d install a manual gauge to see what actual temps the motor is running at. So I installed the temp probe in the back of the intake manifold, where the old electrical sensor was, and now it is overheating...and never did before! Now at 50 mph it’s at 200 (new 195 thermostat) when I slow down in traffic it climbs to 220, and higher if it idles very long. Then pukes into the overflow when I cut it off, never did this before. I can’t see how that temp probe could be causing the problem, but whadda’ I know. The engine is a ’77 Olds 350 with a mild cam, and hot ignition, otherwise stock, and is running the original ’49 radiator that has been flushed etc, and a big electric puller fan that will hold a shop rag up to the radiator, and it runs all the time. Any ideas/info would be appreciated.
Likely got air in the system when messing with the sensors. Figure how to bleed the system and the over heat will go away.
Agree with Joe. Sometimes you can squeeze the bottom hose with it running to push the air out. Turn on the heater and let everything circulate. Check the level after all that. Sent from my iPhone using Tapatalk
recent past flushed out cooling system and have correct coolant mix? correct working rad cap & thermostat?
Just for the heck of it reinstall the old thermostat, if that's all that's been changed. Problems usually rear their ugly head after the last change that was made if it wasn't doin it before!
I've had some problems with air in the system, my radiator sits lower than the heater core assembly in the '65 C10, so I purchased a cool funnel to burp the air out in about fifteen min, look up the Lisle 24680
Another thought. Was the thermostat you removed a 195 degree? Although as I read your post, you may have done the thermostat prior to the gauge and did not have a problem Sent from my iPhone using Tapatalk
Thanx for the replies, but the old electrical gauge died, would not register at all, put in a new thermostat after the overheat problem started, thought it might be the problem, and radiator cap is correct, only change was the new temp probe.....will try and burp the system again.
Puking is normal when a system has been filled up and doesn't have a recovery system - the expanded water has to go somewhere. Maybe you just need to allow it to settle down? Keep topping it up (because you believe it has overheated) and it'll keep puking. Sure the numbers are getting kinda high-ish, but ok-ish nevertheless, but you didn't really know what they were beforehand anyway? And what's already been said, air lock etc. You could test the thermostat and if necessary replace with a lower value (again tested). Chris
The '49 Cad shop manual indicates the water level in the tank is 2.25 inches below the top of the filler neck when cold, 1.75" when the coolant is "at the normal operating temperature of 170 degrees". I believe they used a 180 degree thermostat with a 12 to 15 pound cap. I would suggest running a 180 thermostat and not filling the tank up too much.
That was my point on the thermostat. If the thermostat that was removed was not a 195, I wouldn't have replaced it with one. 180 or 185 max IMHO Sent from my iPhone using Tapatalk
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