I picked up a 1995 Ford E350 camper/motorhome. It has 73,000 miles on it with a 460 engine. I have been trying to get it running right for the last couple weeks because it had been sitting for 3 years or so. Had really bad gas, and was running rough at idle.

Today I drove it the less than 5 minutes to put some gas in it and on the way back, i started hearing valve train ticking. ALso at idle the oil pressure on the dash would drop to 0, and if you touch the gas it will go back up to middle of normal again. But the ticking is starting to get louder and louder. (granted i'm afraid to keep it running so its only been running with this ticking noise for a total of 10mins or less)

While running the engine still runs rough at idle. seems to run good once you touch the gas though. AFTER THIS STARTED, i did change the oil filter to make sure that the old one wasn't clogged or defected. Also it has plenty of oil in it too.

My problem is the oil pressure was fine on the dash for the last couple weeks. Now its registering 0 at idle, and even the slightest rpm increase will bring it up to normal again. But the ticking will not go away at idle or while reving the motor up. and this is pretty sudden too. The motor was not making any odd noise, knocks or tickes before this started less than 10 mins of run time ago.

any ideas? thank you