I recently discovered coolant in my driver side wheel well. It seams like some of the coolant has come out from the top of cap. It hasn't overheated on me, and I wiped down the engine and haven't noticed anymore spewing out, just a little dribble. My heater is working fine, and the temperature gauge is not fluctuating around, it sits where it normally sits. In the last 8k I have changed out the thermostat, which has been fine. I made sure it's in the correct way which it is. The engine is a 4.6 and has around 120k. The truck is a 98.

Any ideas before I start throwing money around at it. It's my daily driver.

 

Clean the cap up real well - w/air and wd40. Blow it out

Is your Coolant between the marks COLD.?

 

Ok I will clean the bottom side of the cap I assume its the spring in there that you are referring too. The coolant is between the lines. It was at the top of the two before, but now since let out some coolant its at the bottom line or a bit above. I'm pretty **** on the fluid levels

 

If cleaning the cap doesn't get it, buy a new one. If that doesn't stop it, find a shop with a CO2 detector. If you have CO2 in the radiator, you have a head gasket issue. But it's probably just the cap.

 

I'm going to cross my fingers and hope its the cap. Do these things go bad?