I have had the heating core go out at 62000 miles.
The exhaust manifold had a leak.
The catylac converter went bad.
Thermostat leaking.
New lifters replaced.
New pushrods replaced.
Replace that thermostat fast! they are not very expensive (around $25 - $55 at Autozone) if you let it keep leaking it will seize and your engine will overheat.
Note: A Comments RSS Feed 
is available. New comments appear in the Members Area before the main site