A buddy is having a small problem. His '00 z28 is losing coolant, not at a fast rate, but he has to top it off every couple of months or so. Oil isn't cloudy, no odd smells, no visible leaks that he can see, no white smoke that he has noticed, and the temp never gets over 210. It also doesn't seem to burn much oil either... The car is stock with 90k on the clock.

What are the chances that it's a head gasket leak? Would it be more probable that it's a faulty radiator cap, or leaky hose he doesn't see, or something small like that?

 

Mine was doing that for a while,maybe a month tops,but was caused by some trapped air in the system after I flushed & refilled the system.He hasn't had the coolant changed recently,has he ? That could be it if he has.If he is only topping it off every month or so & it's not needing a lot it is probably nothing to worry about

 

If its not in the oil, then its not the gasket. Which you have to drain it all and look at it to see if theres any in there, the dipstick does not tell the tale. Plus there would be a noticeable power loss. If it was a leaky hose, there would be a puddle. Based on how you decribe it, cap is my guess. Just make sure he is keeping the coolant/water ratio correct. Thats important.

 

Could also be water pump bearing going out, and weeping out the weep hole.

 

As to the first statement a head gasket can leak coolant out onto the ground without getting any in the oil, mine did on my LS1.

As to the second statement. All you have to do is run the motor for a coulpe of minutes, if there is coolant in there it'll turn the oil a milky brown like a chocolate milkshake.

As to the possible problem I had a 3rd gen v6 that was loosing coolant like that, no puddle or drip, no coolant in the oil. It was the water pump, but it would only leak when warm going down the road. I was stumped 'till it got bad enough that it started leaking at rest.