when ever i start my car my oil pressure goes insane, it bounces all over the place and never stays in one spot. it didnt do this till i went on a road trip which was only 2 and a half hours but its driving me insane myself!! what would cause this? i installed a new switch last year about this time but i put the big one in ( link included) so im lost. should i try and get another switch and install? my wire is on nice and tight so idk what would cause this.

http://www.autozone.com/autozone/par...4001_9275_5673

I'm pretty sure that the oil pressure sending unit has gone bad again. This is really common, as most of them from the parts store are chinese crap and don't last long.

Before you condemn it, make sure you check all your grounds from the engine to the frame and firewall.

Good luck!

well i replaced it and now it just sky rockets to the top and sticks till i turn the car off, like it did when the old unit was bad. so im lost. did i get a bad unit straight out of the store?

Yep!

Honestly, these Auto Zone oil senders are really suspect. If you can go GM parts direct, the dealership(if they have them) or even if you have to order the real AC Delco part, this is definitely the preferred part to have.

yeah well iv got lifetime warrentys on all these units so im getting my money back off that fat one, and replacing the other one. when i can get back to my bigger town where i can get to a deal i will pick it up

I just looked at the Advance Auto Parts website and it seems that you can get the real AC Delco part if you order it. That is what I would do.

Good luck!!

i only have a zone where i live. also i might add that i unhooked the switch then started the car and its still pegging at the top. so does this still indicate a bad switch? atleast the other one let the gauge move lol

mine does too, since i put a k&n oil filter on.

it bugs me, especially driving. to look down and see that gauge going all over the place.

I know how you feel. Mine is original from 89, and it's almost never right.

factory oil pressure gauge should never be trusted. get a mechanical gauge.
they are cheap insurance

I just put a mechanical one in my car today because I couldn't get the stock one to work. I didn't use the nylon hose that comes with them. Instead I used a copper hose kit from oreilly's for lower risk of driving and having oil go all over my interior plus since I just got the engine in there I want to be able to monitor the oil pressure.

The gauge pegs at the top because it's disconnected on the ground side, unlike other cars where it just does nothing.

I think I MAY have my original AC/Delco OPS in the garage. I know I have the 2-wire switch for the fuel pump kicking around (unless I tossed that as well with all of the spare 2.8/3.1 parts I tossed because they're useless without the corresponding parts), but I'll have to dig for the other one. I switched to the 3.1/later models' 3-wire unit and have no use for them. Last I knew, it worked fine (gauge was most likely off, and only had the fuel pump switch installed before I swapped in the 3-wire after the engine swap). You want it, it's yours if I can find it.

BTW, the factory electric gauge can be trusted... Mine's accurate as measured with a mechanical gauge. Just need to get the pointer on the right spot on the gauge needle .

Pegging to the top is the default arrangement, it seems, when the wires are unplugged.

You can get the AC delco one from Auto Zone, too. You can also go online to advance and order the AC Delco one and have it shipped home.

You can even find them on eBay if you have the right GM part number.