[A502GO]

I purchased a 1966 Mustang with a mild built 289. It has sat in my garage for a few weeks and when I started it today my oil prssure at idle would go up to 40 then down to 5-10 then back up to 40. It kept doing this so I eventually just shut down the engine. It's 9.5-1 Comp. Solid lifter cam, Alan Root Aluminum Heads, Roller Rockers. What could the problem be? Thanks for any help or advice.

[EagleAutosports]

Hiya, I see this is your first post.
40 pounds of pressure when cold is fine, and it's normal for pressure to drop to 10 pounds when warm. As long as it doesn't drop to zero, it's ok but if it bothers you, you can step up to a little thicker oil. It sounds like the bearings have clearanced themselves a bit and the thicker oil will take up some of the space. This doesn't mean anything is wrong, it's normal for it to drop like that.

[A502GO]

Yes but it goes to 40 then to 5-10 within 10 seconds then back to 40 then back to 5-10 again. It jus keeps doing this and isn't consistant like it used to be. Any ideas?

[Tominator]

There is a push on connector on the sending unit.

It gets a little loose and causes the fluctuation or no oil pressure.

Check this out first. You can just gently squeeze the connector to make it tighter.

Pull it off the sender and you'll see what I'm referring to.

...Oh!...and WELCOME!

[A502GO]

Thanks I will check it out. I just had the heads off and this makes alot of sense. Will let you know.