OldSchoolMuscle71

ok so I drove home from school today with the a/c on the whole way and its about 95 outside. Its only a 7-8 mile ride.....when i get home i heard a slight bubbling noise so i pop the hood and sure enough the overflow tank was just slightly pooring out of the cap through the vent and i could hear the bubbling from under the rad cap as well. I noticed my coolant looks light brownish. It wasnt smoking or anything but you could tell it was hotter than usual. Could it be poor coolant not doing its job? maybe too much water in the rad? appreciate the help in advance

OldSchoolMuscle71

oh btw i have a new rad, cap, water pump, t-stat, upper/lower hoses. all about a year old with about 7000 miles on the equipment

1970cs

On the trip home 7-8 miles, stop and go or highway? Yes sounds like your coolant needs to be replaced! What does your the inside of your radiator look like? Shrouds and radiator seals in place?

Pat

brown7373

You would have replaced much of the coolant a year ago when you changed the thermostat. You did use new coolant, didn't you? I would never reuse the old stuff. It is a perfect time to add new, even if you don't flush the whole system.

If it hasn't been a problem before, I would check the vacuum advance. If the canister fails, it would cause it to run a little hotter. Also, a thermostat is like a light bulb. Just because it worked yesterday, doesn't mean it'll work today.

How does the oil look? If a head gasket is starting to go, the oil will look milky and the car will overheat in short order.

Hopefully it's something simple. It usually is.

OldSchoolMuscle71

its a highway trip. my oil is good just a little dirty (due soon) but definitely not milky. I'll start with disconnecting my lower hose and draining all that bad coolant into a bucket and fill with new 50/50 and see what happens..

oldcutlass

What was your engine temp? It's normal for the water to expand and push into the overflow bottle. It will get sucked back into the raadiator as it cools due to vacuum.

I do also agree with the others if you have not changed your coolant it's probably time.

OldSchoolMuscle71

i know its normal for it to go back into the reserve but it shouldnt be overflowing out of the reserve ya get me? unfortunately i dont have an engine temp gauge, just the factory warning light that turns red when its too hot and it DID NOT turn on. If i fill the rad to the top and the reserve half way could it continue to boil over the top of the reserve?

oldcutlass

Well it depends on the size of the overflow tank on whether it would overflow. I would invest in an inexpensive set of gauges to mount under your dash. You said your replaced your cap, what pressure is it?

Pick your color:

http://www.summitracing.com/parts/SUN-CP8218/

http://www.summitracing.com/parts/SUN-CP8208/

OldSchoolMuscle71

i have a 16lb cap. my reservoir is probably a 5x5x5