Overheating Issue

[Chryco Psycho]

 

Glad you found it 

[Bullitt-]

GREAT NEWS       I guess I've never had a really bad radiator cap 

[RDF]

GREAT NEWS       I guess I've never had a really bad radiator cap 

Me either.....but it was overheating two nights ago and last night the only thing different that I did was change the cap and put a power steering belt on.....once I did that, it ran 180.....strange indeed...

Thanks to everyone for troubleshooting this with me..... I appreciate everyones input and help......that's why this site rocks so much....people come together for any reason to help a fellow member out.    

[71chally416]

The "The coolant isn't circulating" kinda threw me off. 

[farmertan]

id keep checking for rtv in the rad just in case it was pluged temporarily and could plug again.

[Moparal]

I dont see how the cap made it overheat. Mine wouldnt

[farmertan]

me either you can run a car a long time in the driveway w/no cap thats why earlier he pulled rtv out of rad and if it was plugging a port in the engine somewhere it could happen again,time will tell, i hope hes got it fixed

[Swedefish66/67]

It says in the shop manual, when I read on overheating issues, among other causes, "faulty radiator pressure cap or seat"
Would never have crossed my mind.

[Grancoupe]

I dont see how the cap made it overheat. Mine wouldnt

I mentioned it in one of the previous threads. It raises the boiling point of the coolant when under pressure. But at idle. Not sure why a cap is necessary at idle.

[MEK-Dangerfield]

I mentioned it in one of the previous threads. It raises the boiling point of the coolant when under pressure. But at idle. Not sure why a cap is necessary at idle.

I'm agreeing with you guys here. I can't see starting a car up and having it overheat in a few minutes... with, or without the cap on.   


I'm holding my breath until he drives it and says it's OK.   

[GoodysGotaCuda]

I'm agreeing with you guys here. I can't see starting a car up and having it overheat in a few minutes... with, or without the cap on.  


I'm holding my breath until he drives it and says it's OK.  

Me too, to a certain extent. Everyone's car acts different, but with todays weather I drove about 9miles on the street, and 20 highway miles and forgot to turn my electric fan on. Didn't get over 165*. It's plenty cool out here. All I can think of is the lack of pressure was causing some issue with the flow characteristics of the pump 

[Supercuda]

The radiator cap is very important for cooling system efficiency. The reason that the engine overheated with a bad cap, is because the cooling system is maxed out on cooling efficiency, and needs all the help it can get. My '67 will overheat quickly with no cap or a faulty one, and it all comes down to heat. A better fan, and some other goodies, will help the engine survive with even a faulty cap. With the heater core in the circuit, it is possible it wouldn't have overheated, and the cap wouldn't have been caught until it puked coolant on the ground, and the puddles got annoying. I didn't mention it in my posts, because it had been mentioned already, and there was the concern about coolant circulation. I am glad you discovered your problem.

[Bullitt-]

I  still think that tune may be part of the culprit.... get a timing light & learn how to use it
Here's a cheapie http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=3343
also a vacuum gauge to set the carb http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93547

How to use  http://www.theautoist.com/vacuum_guage.htm

[RDF]

Ok, so I guess I jumped the gun a bit and misdiagnosed my solution for overheating......today was the first time I took it out on the road and sure enough, it began to overheat again.  Fantum was up from Miami and we hit a local car show with JR and Goody and while it didn't overheat, it sure ran hot all the way up there....about 210ish, that was at a steady 3000 RPM on the highway and sometimes at red lights, it got close to 235....

So I'm back to square one with my problem.....I'm guessing it's going to be the radiator as a few others have posted the same problem and the fix seems to be the new radiator.....I could also try a shroud, but I'm not convinced 100% that putting a shroud on would resolve the issue entirely....I'm sure it would help, but only a bandaid on a large wound.....

Someone at the car show told me to get rid of the flex hose for the upper radiator hose and go with a standard hose......I guess I will try that, it's cheaper than a new rad.....but I know you all think I'm probably looney, but on Thursday night when I let the car idle, it sat for a good 15 minutes and didn't get 1 degree over 180....

[bb71challenger]

Ok, so I guess I jumped the gun a bit and misdiagnosed my solution for overheating......today was the first time I took it out on the road and sure enough, it began to overheat again.  Fantum was up from Miami and we hit a local car show with JR and Goody and while it didn't overheat, it sure ran hot all the way up there....about 210ish, that was at a steady 3000 RPM on the highway and sometimes at red lights, it got close to 235....

So I'm back to square one with my problem.....I'm guessing it's going to be the radiator as a few others have posted the same problem and the fix seems to be the new radiator.....I could also try a shroud, but I'm not convinced 100% that putting a shroud on would resolve the issue entirely....I'm sure it would help, but only a bandaid on a large wound.....

Someone at the car show told me to get rid of the flex hose for the upper radiator hose and go with a standard hose......I guess I will try that, it's cheaper than a new rad.....but I know you all think I'm probably looney, but on Thursday night when I let the car idle, it sat for a good 15 minutes and didn't get 1 degree over 180....

I did not know you were lacking a shroud. That can make a BIG difference with a marginal radiator. It made all the difference with my 400 which would overheat slowly but surely running around town. When I put a shroud on it, it never got over 190 after that. You might be money ahead to give that a try.