Last summer i had no temp problems at all, then around late fall right before i put the nova away the tempature would rise and fall all over the place. At first it was just between 160-190 {160* thermostat} So i changed thermostats, last week when i got the new lifters broke in, thinking i had a bum thermostat. New one is also a 160* model. Problem got worse, now it got all the way up to 220 then went right back down to 160-170. I have a full radiator. Its a Howe model stock car style and its allways cooled great so it cant be that. My water pump in a weiand action plus model. Thermostat is 160* Stant. I have generic head gaskets. I had to get the motor together and fired so i got some freebies from a friend. Im thinking its a mildly blown head gasket. but i dont want to tear into it until i get some more opinions first. Theres no coolant in the oil or anything but theres nothing left it really could be is there???

Sounds like it could be air trapped in the block. Try drilling a couple 1/8" in the stat to bleed the air out.

what kind of fan are you running. if its a clutch fan the clutch could be bad.

also try a 180 or 195 stat. it will allow the water to cool more

What are you using for a temp gauge, and have you verified it's accuracy?

Originally posted by chevelleracer:
also try a 180 or 195 stat. it will allow the water to cool more =
This is something that keep popping up from time to time & just isn't true.
Don't know who started this idea but I think it's one of those deals where if it gets written enough it somehow becomes a fact.

It ain't :D

It may have been something that worked about 40 years ago when you had inefficient pumps & radiators compared to today but current technology in cooling says the faster you can move the water the better it will cool.

Here's some good reading:
Restrictors & thermostats (http://www.stewartcomponents.com/html/tech_support/techtip3.asp)

smile.gif

You are kidding right. I will agree that not running a thermostate will cause overheating in most cases but a 160 will not cause an engine to run hotter. To the problem every thermostate that I have gotten in the last few years has had the problem of going to 220 before it opens the first time after setting all night. They always work correcty after that but I have no clue why. I see the previous post was deleted while I was typing.

You can have a pressure check done to find out if there is a leak. I've heard that radator shops can check for combustion gases in the coolent. That would tell you if the head gasket is gone.

Originally posted by Mike Feudo:
You are kidding right. I will agree that not running a thermostate will cause overheating in most cases but a 160 will not cause an engine to run hotter. To the problem every thermostate that I have gotten in the last few years has had the problem of going to 220 before it opens the first time after setting all night. They always work correcty after that but I have no clue why. I see the previous post was deleted while I was typing. =
Did I miss something?? :D
Damn, never payin attention,, that's what I used to hear in school too graemlins/clonk.gif

Mike the post was deleted while I was typing. Should have changed the whole post instead of adding the sentence. Sorry for the confusion.

probably ran hot becuase of an air pocket.

Well i changed the thermostat again, drilled 2 .125" holes in it, ran it again and....same thing. Then we noticed my lower radiator hose is MUCH cooler, almost cold, while my upper one is hot, that says water isnt flowing, so it has to be my water pump, wouldnt ya think???

It could also be a plugged up radiator. Any rad shop can check that quickly enough.