engine noise??????????

[justice95]

95 j30 on start up it makes a knocking sound that stays.....damn this is hard to describe so to keep it simple it sounds like loose bearings but.... its not. occasionally it will just go away....... does not affect performance at all. noise comes from passenger side almost like a blown air pump...exhaust leak... ive worked on anything that starts since 1975 and this has me reeling............. i need help please.... also reverse has been gone for almost two years.. all foward gears work perfect 1 2 3 and d any ideas and input from all you guys would be most appreciated..thanks

[GerryO]

A couple of questions; has the car recently or ever sat for a long period of time without being started and why type of engine oil are you using?

I once parked mine for a while due to a leaky water pump, waiting for parts and the opportunity to replace it, starting/moving it once or twice a month. Soon I was more worried about a loud knocking sound than I was about the leaky WP. Adding 1/2 quart of heavy weight synthetic oil quickly silenced the knock, and fully converting to synthetic and driving the car regularly have kept things quiet.