85 Nissan 720 4x4 Oil pressure switch

[Thomas Perkins]

Happy Monday Ya'll.I called O'Reilly's over the weekend to get a lifetime warranty exchange on my oil pressure switch.I have my receipt.They always use your phone number to look up your buying history.She said she does not see it,then I told her I had the receipt,then she asked me for the P.O.number,then said she don't see it then said hold on then said it will be here Wednesday.I bought it over 7 years ago,always keep your receipt from them cause a salesman there told me after a certain amount of time they erase your old purchases.I also bought my Rancho 5000 shocks from them,also have a lifetime warranty on them.They went up 11 dollars on the switch from when I bought it.I will change the oil when it comes in.Their Wix 51515 oil filters went up to 13.99.Too bad they don't have lifetime warranties on them.The fitting on the wiring dry rotted long ago,so I put the blue female fittings on it.Dont cross them.up.Easy to replace.

Edited October 7, 2024 by Thomas Perkins

[Thomas Perkins]

When I change the switch.I turn the wheel out so I can crawl in there and remove  it..I always remove the oil filter first.I will do that after work tomorrow,got to take it off so I can get a replacement.Same as doing the starter.I remove the oil filter from the top.First I disconnect the battery cable.What I use to remove my oil filter on both of our vehicles my wife car uses a smaller one,it is under her car.The one's  I have are from Walmart.I did tear up the fittings on the oil pressure switch seven years ago when I got this switch from O'Reillys.Using that oil filter wrench.Too much stuff in the way.

Edited October 8, 2024 by Thomas Perkins

[Thomas Perkins]

I was using this type,too bulky.

[Thomas Perkins]

Hi Ya'll.I ended up not taking off the oil filter,have less than a 1000 miles on the oil.I used a regular size 14 mm to loosen the oil pressure switch from the top,then I used a little 14 mm to loosen it more with 2 turns then used a rag and  took it off.I am going to put new female fittings on it.I did jack it up.It was real easy taking it off.Love these little wrenches.I mainly use metric.Same size as the oil pan bolt.A 9/16 will work.

[Thomas Perkins]

Both wires are white with a blue strip.I did draw a diagram,how they go on by the angle the fittings are on the part.

Edited October 8, 2024 by Thomas Perkins

[Thomas Perkins]

Your not going to believe this.There was nothing  wrong with my oil pressure switch.When I removed it,one of the fittings was covered with coolant.Since I done ordered a new one.I just went and picked it up today.The heater hose above it was leaking and it was right over the switch.So ,I got my 1/4 inch rachet and 5/16 inch socket and tightened it.I was wondering where the leak was.It was not a real big leak.No puddle under truck.I did end up changing the oil and oil filter.I did change my coolant not long ago and at first thought the coolant on the connection was from that.When ever I change the coolant,I never use the drain plug,I just remove the bottom radiator hose and let drain in a 5 gallon bucket.Oh we'll.Check out the hose above the oil pressure switch and the two wet looking spots.The switch just started to read low.On the highway,about 45-47,then to 42.Then when  I stopped at red light at Idle,it went to about 15,normally at 30.So now it is ready like it was,back to normal.

Edited October 10, 2024 by Thomas Perkins

[Thomas Perkins]

[Thomas Perkins]

[Thomas Perkins]

[Thomas Perkins]

[Thomas Perkins]

Check this out.My owners manual says use 4 1/2 quarts of oil ,and my 85 Nissan FSM says to use 4 1/4 quarts of oil.So who is right?The FSM does not say what weight to use, it depends on your weather conditions, so 10W30 or 10W40 is for my weather conditions.

Edited October 10, 2024 by Thomas Perkins

[datzenmike]

That's with or without new empty filter. Myself I always change the filter.

[Thomas Perkins]

That is with a new filter.Here is my owners manual saying 4 1/2 qts. Mike.FSM says 4 1/4 qts.Cant show that right now,I am eating lunch in my truck at work. I will show it when I get home.This is the same showing in the FSM,except how much it holds.

Edited October 10, 2024 by Thomas Perkins

[Thomas Perkins]

My Brand new Owners manual.

Edited October 10, 2024 by Thomas Perkins

[Thomas Perkins]

My Original owners manual.

[Thomas Perkins]

I always change the filter too Mike.

Edited October 10, 2024 by Thomas Perkins

[Thomas Perkins]

I got 394,034 miles on my speedomter now,over 108,000 miles on the Jasper engine that I had installed back in 2009

 

 

Edited October 10, 2024 by Thomas Perkins

[datzenmike]

Next oil change stick 4 1/4 Qts in and read the dipstick. I doubt an extra 1/4 Qt will matter.

[Thomas Perkins]

Your right mike.

[ElliotV]

Hey thomas one thing I will note and I don't know if maybe I got a bad sensor or something but the one I picked up from oreillys back in april does read low for some reason. the oe sesnor would read about 60-65psi down the highway and warm would idle at about 30-35 now it reads 20-25 at idle and when its cold I can literally watch the gauge stop at 45lbs and it will max out at that going down the highway too and it reads just below 45 once warmed up. I did notice on mine that the new sensor did not have a countersink on the hole and the hole itself was smaller. Just my 2c on it and the only reason I replaced the original was because it started leaking. One of those things I just wish I could get a oem one that hasn't been sitting on a shelf for 40 years.

[Thomas Perkins]

Yours is reading correct.I 've had my 720 for over 30 years.Yours is reading just like mine.Your other one was bad and reading high .Mine reads 47 on the road and 20-25 idling.It has always read that.The one I replaced was good but coolant from the heater hose above it leaked coolant into the fittings and it started reading low.All I had to do was wipe the fittings and change the female fittings and tighten up the clamp on the hose.The clamp was tighten and the hose no. longer leaks.The hose can be gotten to by turning the wheel out and get in there and you can see everything in there.But your oil pressure switch is working correct.I always use tephlon tape on mine,never has leaked,just be careful when removing the oil filter,one time it broke off one of the fittings on the oil pressure switch and I went and bought a new one from Orellys.

Edited October 11, 2024 by Thomas Perkins

[datzenmike]

50-55 is about right and engine wear determines hot idle pressure. I also replaced the stock oil pump with a KA high volume pump so idle is 30-35. I lightly shimmed the relief valve for high 50s when revved up. The higher volume pump maxes out at the same higher pressure but at all other revs is slightly higher and gets there sooner. Have a digital pressure gauge.

[Thomas Perkins]

That is way too high for the Z24 Mike.45  to 47 is good on road.20 -25 on idle.Been like this on mine for 30 years on original engine and Jasper engine.Always stays the same,Idles and drives perfect.Rpm needle on dash does not move when idling.Idles at the exact same place all the time. Nothing changes.

Edited October 12, 2024 by Thomas Perkins

[Thomas Perkins]

There is a used Oem Nissan switch for sale on Ebay,about 75 bucks.

Edited October 12, 2024 by Thomas Perkins

[Thomas Perkins]

Nissan's 720 oil pressure switches were 344.18 when they had them.