losing coolant

[dab67]

Not sure this is where to post this question but here goes.
My 67 Camaro 350 either is using or losing radiator coolant about every 30 days or so. I can not find any leaks from the engine or the radiator so I am guessing it is either being used? or evaporating.
Anyone else have this situation?

Thanks in advance.

dab67

[bertfam]

How much are you loosing? The first generation Camaro cooling system isn't a "closed" system like they have now. It's perfectly normal to loose an inch or so every 30 days depending on how much you're driving the car, maybe even more.

Ed

[dab67]

Ed:

Thanks for reply. That is about what I am losing ( 1 inch) every 30 days or so. I drive it as much as possible and only become aware of the lost fluid when I get into slow traffic and my temp gauge goes past half way. Then I let the car sit overnite and check it in the morning. I fill to about an inch below the top of radiator. The heater core started leaking this year and have disconnected the hoses from the core so I know there are no leaks from that area. Not sure I am going to replace the core, I did this about 6 years ago and don't want to do it again.

dab67

[bertfam]

An inch below the top of the radiator is too high. Look at the engine side of the radiator about 3 or 4 inches under the filler neck and you'll see a line and "FULL COLD" ,indicating how far to fill (when the engine is cold). Any more than that and the radiator will "puke" out the excess. That's probably where you're loosing it.

If you're gauge is going just past half way in slow traffic, it's not that bad. Mine gets to just under half during the same scenerio. Remember, these gauges aren't that accurate so to really check the temps, go out and buy an IR thermometer. I got THIS ONE a few years ago from Harbor Freight and it showed my gauge to be about 15 degrees high!!

Ed

[dab67]

Thanks Ed for the info.

I have a friend that has a IR thermo to check heat with. I'll use it to check the accuracy of the gauges in my car. And I will look for the line for fill on the radiator.

Thanks again!

dab67

[tom]

Check you radiator cap as well. It is supposed to release excessive pressure. If the seal is bad, or if the spring has weakened, it could be letting off too much pressure. If I recall right 14 or 15 pounds pressure was normal back in the day.

[GaryL]

I had my engine oil analyzed a few years back to check on wear, zinc content etc. Found I had a coolant leak. It was comimng thru the screw in rocker studs. I check it once a year now. You can visually check by looking carefully in the oil return area of the heads.