Help with coolant leak

Help, Yesterday I noticed that my check gauge light was on. I immediately stopped at a service station and had the oil changed and the fluids checked. The mechanic changed the oil and said that there was an orange substance around the drain plug. I forgot that I had put an oil additive in that was orange in color. He also said that the water was low and that he was unable to see any coolant in the top of the radiator so he added some. He also indicated that there was a lot of corrosion around the cap and that I would need to flush the radiator very soon.
Now, I don't have any problems with smoke or milky oil, but the service manager said that I may have a blown head gasket or intake valve. (again, I never told him about the additive). The next day, I checked the radiator and the water was low again. There is no obvious leak. I cannot see where the coolant could be leaking from. The service manager said that there did not appear to be any water in the oil or oil in the water. Does anyone have any suggestions? I need help!!!!!!

Thanks, Jim

Well, first off... since you obviously notice a change in fluid level... I woud inspect around all of the radiator hose connections, both on the radiator and the engine.

Next, check the drain plug to be sure it is tight.

After that, check the seal of the hoses running to the heater. There are 2 located on the passenger side firewall area.

If no visible leakage, then refill the radiator to correct level.

Place cardboard under the truck, or park on a clean garage surface, and allow to idle for 20 minutes. Come back and inspect or puddles/drips.

It sounds as if the oil change guy may have seen the orange coolant the factory sends out. If thats the case, he would have seen it in the oil. Then again, they drain it into a can with a long neck and a pan. If you arent watching the whole time its draining (usually when he is changing the filter), then you may not notice!!

Change your oil yourself, check it yourself. If you have coolant in there, get your gasket fixed asap.

Lastly, check your transmission dipstick. Idle for 10 minutes from a cold start. Give it a full shift from park to 1st and back. Check your dipstick twice, you are looking for foam or milky-looking fluid. If you see foam, service the transmission. The tranny tech will let you know if a seal failed inside the tranny that could have caused coolant to leak into the tranny (I hope its not that!).

Good luck.

Check your carpet to see if it is wet, if so check your heater core under the dash, passenger side.