Just about ready to take the brick into the dealership...I suspect a bad seal. I continue to get moisture in the distributor cap that causes missing. I have replaced the wires, cap, and rotor and continue to get the moisture...not oily or coolant. I just run a hair dryer and it evaporates. I did check the breather hose to the valve case and the same moisture was present. I clean and replace the cap and it runs great for a while and then the miss comes back. No error codes other than missfire when moisture appears. Any suggestions for testing or cause would be greatly appreciated

Thanks, the problem started before replacing the distributor cap (replaced with Bosch OEM cap/wires)and problem continues. Car runs fine for about about an hour or so and then starts to miss. The moisture seems to collect more/cause more missfires when left to set after running for an extended time. Each time I remove the distributor cap and there is condensation in the cap. Wipe out and replace cap...the car runs fine for a while and we repeat the process. I have been extra careful to avoid any contamination and make sure the engine compartment does not get wet...I'm stumped unless I got a leaking cap, but the problem began before the replacement was installed.

Could it be a bad seal and vapor from the valve area is condensing in the cap?
Any thoughts would be appreciated.

The camshaft seal if bad would allow oil into distributor. I think it would probably drip out without accumulating in the cap. There's no cooling passage up that high on the engine. I think you mean moisture gets INSIDE the distributor cap?

Did the problem occur before you replaced the cap - and did replacing the cap do you no good to solve the problem? If so are you buying genuine Bosch caps that match OEM specs? I've had aftermarket ignition parts on various cars that did not pass muster.

You might try the old trick of watching the engine run at night so that you can verify exactly how the ignition is leaking or arcing over.

Do you live or drive in an area with very unusual weather or badly polluted air?