I need to conduct an oil pressure test.

I think have located the oil pressure switch ('03 disco II), but before I go around tickering and messing things up, I want to get my ducks lined up and make sure I do this right the 1st time. First, confirm where the switch is located.

1. Is it easier to access the switch from the hood (front passenger, top and right of oil filter) or from below? RAVE manual is pretty clear as to the location of the switch but for this virgin mechanic, if you have some .jpgs to share so that I get it right the 1st time, would be helpful.
2. Next, what socket or wrench size to do I need to unscrew the switch?
3. Purchased an OPT kit from Harbor Fright (no typo, a little humor) but not sure if the correct adapter is in the kit. Anybody know the specific adapter size needed to insert where the switch once was?
4. Finally need to conduct four readings; two readings when engine is cold and two tests when engine is warm/hot. Can I simply leave the oil pressure gauge and the adapter attached to the engine and let the Landy idle for about a 1/2 to warm up? Or, should I reinsert the OPS, road test the Landy 'till she's nice and hot, then park it and rinse, lather and repeat?

Any other advice for me is welcome, even if there is a sticky on this forum to assist me.

Thanks,
Rob

 

The oil pressure switch is next to the oil filter, not sure what you are looking at.

 

The kit from Harbor Freight did not have the exact adapter as I recall, but I found one in the blister pack aisle for brake parts. If you unplug the connector from the switch the oil light will not come on when you start truck, because there is no ground for it.

Oil pressure test is done cold, idle and 2500 rpm , then when fully warmed up, again at idle and 2500 rpm. You end up with four numbers. The idle number starts high, as oil is thick and bypass valve in filter shunts liquid around the filter media. As heats up, bypass valve allows oil to pass thru media. Lower PSI at idle, but still well above 10. D2 should produce 50 PSI at higher speeds or better. D1 is rated 40. I was happy to see 44 on my D1. Will see what I have after valve train work.

Work from below. Leave gauge in while engine warms up, don't drive it.

 

The thread on my 2003 pressure switch was M12 x 1.5
This should help your search
FWIW, I understand that early D2 pressure switches are 1/8"

Edit:
http://www.ebay.com/itm/181162226131

 

Found OPS, unscrewed OPS, screwed in adapter. Problem is I am having one heck of a time screwing in the Oil Pressure reader to the adapter. I have also screwed the adapter onto the reader first, then attempted to screw in the adapter where the OPS was. Ain't working. Any other sage advice on how to do this.

my disclaimer, I'm a rookie, so I'm just getting my feet wet on all of this DIY maintenance. Might be that I need patience.


Thanks,
Rob

 

Hi Guys, Seeing as how you are all talking about oil pressure switches etc., I figured I would ask a question here. I had my oil pressure switch changed about 2-3 months ago. Well long story short the oil light came back on (here and there) so I took it into the shop again. They changed the switch again and then told this: Turns out that under 1500rpm my oil pressure is on the low side, in idle and such. Furthermore, the guy told me that either A) I could get a new engine or B) he wants to replace the bearings I believe he was referring to the main bearing(s).

That being said.... I thought to myself. WHY the hell did he not mention just getting a new oil pump and seeing if that rectifies the issue? Why did he just jump to saying "new engine" or "main bearing(s)" I feel like this is ridiculous and that, its pointless to do all that work without actually changing the damn oil pump first...

I checked my oil levels too and the dip stick was fine. But at the shop the guy says the oil is disappearing... Explain that one to me...

What are your thoughts guys? Seems a bit off to me thats for sure!

 

@Bartlomiej What did you end up doing?

 

@SouthxSW Super old thread. You might want to start a new one. If your oil light is flickering, you have five possibilities:

1. Low oil pressure caused by:
   1. Broken oil pump gears (50% chance)
   2. Walked cam bearing (50% chance)
   3. Worn rod bearings (fairly rare)
   4. Worn rocker shafts (also fairly rare).
2. Bad oil pressure switch.

Suggest you start with an oil pressure test and go from there.