rotary#10

iTrader: (38)

ok last time i replaced my my oil pressure gauge the needle went below the line of zero. not it doesn't do that but the it doesn't respond well to the increase in throttle. oddly i soulder up the wiring that connects oil level sensor. haven't tested it yet but it turns on with the rest of the lights when the key is on the position on the ignition switch. so i beilieve it works and it turns off when i start the car. but the oil pressure guage stay at ZERO ( 0 ) until the car has warmed up and or hit operating temp. it even drops to zero when im driving on the freeway..
im check the connection of the oil pressure and the sender and see of the connection is dirty and also the ECU hopefully i haven't burnt another HOLE in a good ecu.

I called peter my rx7 mechanic and he said thats its either the oil pressure sender unit or an electrical problem.
so how do u remove the old oil pressure sender unit ?

and is it alright to drive on it like this ? even though it say zero pressure is there still oil going to the motor ?

puhpaper

iTrader: (6)

sender has been known to be a prime candidate for failure. i sincerely doubt you have 0 oil pressure, if you REALLY want to know that badly, take your oil filter off while the car is on. if it blasts oil - congratulations, you have oil pressure!

stormshadow531

iTrader: (5)

it's easy to remove, i think it's like a 12mm. you have to use an open-end wrench though. turn, flip, turn, flip. annoying but not hard.

rotary#10

iTrader: (38)

mmm now im thinking of upgrading to a after market gauge for oil pressure and engine temp. since I've heard that these are inaccurate at times
but yeah i'll replace the sender unit and see what that does.

HAILERS

IF, with the key to OFF, the oil pressure gauge needle is below the bottom hash mark, then the GAUGE is part of the problem. It should NEVER go below the lowest hash mark.

What WILL cause this symptom, is if someone dead shorts the oil pressure sensor connector to...gnd for a prolonged period of time. What happens is the needle drives hard up and once at the very top. starts slipping on the needle shaft. So now you turn the key OFF, and the needled drops, but instead of stopping at the lowest hash mark, drops waaaay lower.

Partial fix: remove the gauge cluster and the clear cover off the face. Delicatly pull the needle off and then reattach it but this time with the needle directly across from the lowest hash mark. Reassy the damn thing and turn the key ON. Needle should stay at the hash mark. Start the engine. Needle should, at 3000rpm plus go to sixty plus psi when the oil is HOT.

Unfortunatley this will probably not solve the whole problem. If the sender output wire has been dead shorted for a prolonged period of time..........the gauge is a piece of .......and you need to get another out of a wrecked car.

Just my humble opinion.

I think this is your problem. But, lets ask this. Does the needle go say ten or more needle widths below the lower hash mark with the key to OFF? And when you start the car the needle rises all the way up to zero or the lower hash mark? IF that is the case, the car is safe to drive imho until you can aquire another gauge.

rotary#10

iTrader: (38)

piece of crap.. when i turn the car on first in the morning ITS AT ZERO... but after some stop n go driving and hiting operating temp.... it comes on and it shows the pressure, but at times it cuts off; and thats a good 75 % of the driving the car at operating... lol i remember driving on the freeway today and it said zero lol! could it be an electrical short ? the wire to the harness was spliced and the wire to the connector is spliced both ends spliced, are crimped could it be that the copper in the crimps expand with the heat causing the connect in the crimps to tighten giving a accurate reading? i would still like your folks 411 on it.

AreExSevenProject

iTrader: (1)

my oil guage has never worked...
doesnt come up PERIOD.

Chris Boots

Mine hasn't worked since I bought the car. The one time I plugged it into the sender the needle went all the way to the top and stayed there even with the car not running. Now the needle sits way lower then where it should be.

pfsantos

iTrader: (1)

Oil sender is 14mm wrench size, tapered thread (use teflon tape when installing). Removed one yesterday.

For future reference...

Coolant sender nearby is 12mm wrench / deep socket size, regular thread (has a sealing washer).

HAILERS

That has the symptoms I mentioned in my post above. It's probably that the OTHER wire for the oil pressure sensor, the one that gets a capacitor attached to it, was connected to ground. That would explain the drive up to the top of the gauge.

Unfortunatly that most likely did in the GAUGE. You can remove the plastic cover of the combination meter and remove the needle and then put it back on the gauges shaft. But when you turn the key back to On and start the engine, the gauge won't read accuratly. The needle will now rest at zero with the engine off, but once on the needle will rise, but won't rise up to the approx 60psi where it should at 3000 rpm.

The fix is to buy a combinaton meter out of the wreckyard, same year/model, and either take the voltmeter/oil pressure gauge out and put it in your car or just swap combination meters.

The oil pressure guages/senders are not the culprit. The culprit is at sometime, someone dead shorted the senders wire for a prolonged period of time and screwed the system up.

Turn the key to ON. Have someone take the senders wire connector and hold it against the engine for a moment. When he first touches the engine with the senders wire, the gauge needle should rise, proving the circuit is good to the gauge. He should only hold it on the engine for a brief period of time. Like no longer than for you to see the needle starting to rise up.


A short would drive the needle to the top of the gauge. Ain't no short.

It sounds like a *open* in the senders output wire. Bad splice or bad connection at the sender. Fix same.

If the needle just drops to zero, and no lower, then disregard my first post. Also take note that is someone in this cars life ever dead shorted that output wire to gnd, he screwed up the system. Not the sender, but the gauge circuit.

AreExSevenProject

iTrader: (1)

ill try that oil pressure trick...i think my line dangles...then i connect it...then it dangles...Its a P.O.S. lol

HAILERS

There's a easy way to check out the oil pressure gauge. Just look in the FSM, I think Body Electrical.

What the deal is, is that you take a resistor of a given value, and attach it to the senders output wire. Then attach the other end of the resistor to gnd. The gauge should rise to a given PSI for that resistance. Like you take a 140 ohm resistor and put it on the end of the wire. Other end to gnd. Key to ON. Gauge goes up to 60 psi.

The manual gives several different resistances for several different psi.