I took the valve covers off tonight, never been off since new, 140K miles ago. It looks good under ther except for some slime looking residue on the top of the valve covers. I've seen what a blown headgasket looks like, this isn't it. No water in the oil or oil in the radiator . Do these stock valve covers create alot of condensation. Possible that just over time its created a film of it? You can tell that it is water, but not like a bad gasket or tons of water getting into it. The car had sat for about a year befor being started up and driven to my garage. Any thoughts? Thanks, Tim

 

If this is a banned topic, where should it be? It's not the average water in the valve cover means blown headgasket, I've never seen a condition like this. Thanks again, Tim

 

It comes from not running the engine long enough to evaporate the moisture present in the air inside of it.

 

could also be combustion products from blowby and a less than perfectly functioning PCV system.

 

well i have a theory...
if the engine sits with humid air in it, and then the outside air cools.... the valve covers cool and condensation forms...


but if you run the engine regulary, you wont have this problem... *shrug*

 

So thats what the slime looking stuff is? Makes sense. Thanks, Tim