Oil Pressure gage pegs out

[6.5rollback]

I recently replace my fuel filter housing because it was leaking at the bottom. Since then, and never before after I start up, about 30-60 secs the oil pressure gage goes from idling 40PSI to way over past the max, the needle points to about 3 o'clock. Any idea's? I'm guessing I bumped a ground.

[grancito]

You did something to the electrical connection to the oil pressure sender, which is near the fuel filter.

[jimclemjr]

Doesn't the sending unit just read a varible ground that the sending unit gives it by the pressure acting on a electrical resistance slide or something? i am having some minor erratic activity on my gauge just jumping between 40 to 55 PSI and figuring I need to check the wire connection to the sending unit --just too cold to mess with a minor issue- ha.

[jimclemjr]

Sorry I meant Gauge reads the sending unit, of course.

[grancito]

Yes something like that. One wire into the sender through the variable resistor to ground in the sender. Bad connection gives a high pressure reading.

[jimclemjr]

Just a FYI for all on my experience the past 24 hours. Had a 'quit' episode last night but it would restart with difficulty so sure enough no fuel out bleeder and I focused on OPS and Lift pump. Piggybacked the pump connection and I was getting voltage on start mode but noticed it was low and erratic and would not start normal. So replaced the OPS w/ a backup Orelly's unit I have been carrying around for a 1 1/2 years. Started fine after bleeding. Then I noticed that the oil gauge was pegged over 80 psi and was unaffected by RPM. Replaced OPS w/ an ACDelco unit and all is fine. The erratic oil pressure reading I was havin is now gone. Moral-careful of the aftermarket OPS units and the erratic oil pressure readings I was having might have been a precursor to the OPS failure.

[grancito]

A bit late replying, but thanks for the feed back, it is valuable for everyone on the site.