Irregular miss/stumble on acceleration. "Putters", then catches up. Seems to get worse as engine temp increases. Can drive 5 miles to work with no problems. Drive another 3-5 and gets increasingly worse. Plugs reasonably new, new air filter, injectors cleaned. I suspect the PCV system, as I see some oil weeping from valve covers. Suggestions?

 

Any trouble codes, how many miles on your truck, what octane gas are you running, have you checked all you vaccum lines? I wouldn't worry about the V/C gaskets leaking that is normal. How old are your plug wires?
Mike

 

About 150K miles. Plugs, dist. cap and wires replaced in last year. Ordinarily run mid-grade gas, but running premium right now. Also running another injector cleaner through this tank. Vacuum lines checked with carb cleaner, no apparent problem. Have not checked codes.
What is fascinating is that it has run trouble free for the last two days. No symptoms whatsoever. Now wondering whether it might have been the injectors after all (nearing end of full tank of premium with injector cleaner in it).
Put about 40K miles on it since I bought it used. Know it has not had any PCV service in that time.