Another overheating question

[LaneRover]

Any chance the water pump impellor isn't pumping much anymore?

Or that your timing advance isn't working too well?

[Nium]

I stuck a thermometer in the radiator after gauge read in the red. I got 145° . Let me add that I'm running without the thermostat. Also, when I oened the raxiator I noticed the antifreeze was foamy. Is that normal? I also noticed the smallest pinhole leak out of the radiator. Could that cause the foaming? Or even the overheat conditions? What temp is overheating in a series III? thanks

Normal operating temp for a 4 cylinder should be between 180F and 200F. Overheating would be 220F+. The thermostat wouldn't even open until the temp reached 72C or 162F (Series III manual thermostat rating).

Foamy antifreeze doesn't seem normal.

IMHO a pinhole leak would keep the cooling system from maintaining the correct pressure of around 9 lbf in^2 (which is the rating of the radiator cap according to the Series III manual)

[JHK07]

What about an air pocket/ bubble in the cooling loop? When i changed my T-stat a couple of weeks ago I think i had 1. It overheated on 1st start, bout 220, i shut it down immediately.


Anyway, jacked up the front end and added coolant as engine was running.

Goosed gas pedal w/ hand... add more coolant. Repeat as necessary.

It got to 180 plus and the new stat opened.

[cousindave]

Hi everyone, thanks for the responses! Had time today to install a new mechanical pump to the old bird. Guess what? The temps never go above 140° without the thermostat. But, there is alot of foaming in the radiator. Went to napa and got some radiator cleaner. Wish me luck!

[cousindave]

Ok, so i used napa radiator cleaner. Stuff is awesome! Gray crap came out of the petcocks. Nasty. No more foam in the radiator!! Totally psyched!!

[Nium]