[doc j]

The coolant level in my recovery bottle is very slowly decreasing, I have to refill it every 3 or 4 months. I don't see any signs of leakage, the hoses and cap have been replaced within the year, but I can occasionally smell anti-freeze around the engine compartment. The last compression check ranged from 139 to 145 PSI (69 307)and the oil doesn't smell of coolant when changed.
So, I'm wondering, has anyone ever heard of a MICRO pin-hole leak that would vaporize leaking coolant?

[Corey872]

You may be on the right track. I have seen some different forms of leaks that really don't seem to show up. If course the engine can leak directly into the combustion chamber...if it's small you usually don't see steam in the exhaust pipe or significant coolant in the oil. But seeing as how you mention smelling coolant, I would suspect that you have a small leak in the radiator. The coolant is not vaporized specifically because of the size of the hole, but it seeps out slow enough that the heat of the radiator and airflow can evaporate most of it.

In your case (since you can smell it)...Get a "black light"...you can usually find them at different places for around $10. Get the fluorescent type not the incandescent. Go out some night after dark and look at your radiator and engine with the black light. If you have a leak, the coolant is evaporating, but the tracer dye is staying behind. You should see bright green marks identifying the leak.

[Black69]

I had a leak in the front of the manifold. It would leak when the engine got warm and there were no signs of where the leak was when it was stopped or even when first started. But like you said, I would have to fill the coolant quite often. Do a pressure test on the cooling and hopefully you will find it.

[Chuck Constantine]

If your running plain water it could be evaporating but since you said you get a sweet smell I assume your running anti-freeze so thats not a problem. You could have a pinhole leak in the heater core. Mine started with a couple of drips then one day it blew inside. What a mess

If you have a leaky head gasket you can usually smell it in the exhaust and not necessarly in the oil.

[doc j]

Thanks, I kinda suspect the radiator, I bought it new 4 years ago but had it repaired twice already for leaks in the solder joints on the tanks. The heater core was replaced at the same time and I'm really hoping it's not that or a head gasket, radiators are SOOO much easier to pull. [img]smile.gif[/img]

Jim