RXzeben

my oil pressure gauge is shooting straight up!
is this a ground issue?

NCross

iTrader: (18)

Clean the connection on your sender.

mo-powah

check all connections. the sender needs to be ground properly

RXzeben

oh so its more of a lack of a ground?

and what about if the water temp sensor is plugged in but not working?
and when i ground the wire to the temp sensor the gauge bounces down then back to 0

mo-powah

its lack of ground if it redlines and if its at 0 its clogged or doesnt have power.

RXzeben

SWEET! thank you, any idea about the temp sensor?

clokker

iTrader: (2)

That's backwards.
If the gauge pegs out, the wire is grounding somewhere between the sending unit and the cluster.
If you get no reading at all, the wire is either broken or disconnected from the sending unit.
If your reading is low, the diaphram in the sender is worn out and the unit needs replacing...or you have really low oil pressure.

Seems likely that the OP has a wiring problem since both the oil and water gauges are acting up.

NCross

iTrader: (18)

Check your resistor packs or whatever theyre called. The little black things that should be bolted to your clutch cylinder. Just clean your sender prong and plug. That should be the problem. Oil can drip from the oil filter and gum it up. Very common.

RXzeben

what about if its pegging out and the wire connected to the oil pressure isnt plugged in?

NCross

iTrader: (18)

The wire needs to be plugged in. You mean it reads the same regardless of if it's plugged in or not? Your gauges must be screwed or your not grounded at all.

clokker

iTrader: (2)

Then I would suspect that you have a wiring problem between the gauge and the sending unit...it's getting a ground from somewhere.

KhanArtisT

iTrader: (2)

Check the connector for the gauge cluster on the back to see if its connected properly. Loose connection will make the gauges shoot up. Smack the cluster when it acts up though and see if it reads normal.

RXzeben

yea it the same whether its plugged in or not.


i tried it with two clusters and it didnt help the temp or the O.P.

blackrotary23

i would just get an aftermarket gauge from autozone. i did. it reads perfect. easy install as well.

Aaron Cake

iTrader: (1)

I would prefer the quality of the OEM gauge over some rebranded made in China junk that AutoZone sells.

HAILERS2

Ah man, Clokker got it right and a whole bunch got it so wrong.

IF the wire on the oil pressure sender is touching ground it will cause the gauge to peg out.

If the wire on the sender falls off and hangs in mid air.........the gauge will not move up or down.

The wire on the oil pressure sender is also spliced into another wire that goes to a condenser that normally gets bolted to the clutch slave cylinder. If that condenser has it's wire broken and bare wire is touching ground (like the block) then the gauge will peg out at the top.

If the wire is on the oil pressure sender, then go look for the condensers wire and see if it's grounded out.

The gauge is not pegging out because it LACKS a ground, its pegging out because the output wire of the sender is grounded.

Once pegged out and left in that condition, there's a good chance the gauge will now be disfunctional. As in not being accurate no 'mo.

clokker

iTrader: (2)

Do I get a cookie?

RXzeben

OH! i dont have anything bolted to the slave! i did not know that, i'll look tmr thank you guys!
but it goes up and down when i turn the car on or off, so im guessing it should still be good?

RXzeben

Hailer-

i was looking at the diagram you gave, my car is a 90 NA; does that matter at all?

HAILERS2

Series five is the same thing.

The oil pressure gauge will work just fine without the condenser being connected up. But if someone saw a broken off wire where the condenser should be, and decided it must be a gnd wire and grounded it, then the gauge pegs out.

Just pull the connector off the oil sender and put the key ON. IF the gauge is rising and pegging out, then look for the other wire. It's the same color. Unground it.

kaioken

iTrader: (2)

Sorry to steal this thread, but I have a similar problem or at least I think I might. We were able to get my S4 on the road for the very first time, My first time driving a Rx7. I noticed that my oil pressure is about 90psi when under throttle. Is that the norm? It seems kind of high.

Bill

clokker

iTrader: (2)

If you gauge reads lower than 90psi at idle and rises with engine speed, then you don't have a similar problem.
In fact, high oil pressure is a "problem" many here wish they had.

90 psi does seem a bit high...normally you'd expect @30 at idle and 60-70psi at 3k RPM.
But you could have many things going on to explain your higher readings-

-Is it the stock gauge and sending unit?
-Fresh rebuild on the motor?
-Shimmed (or possibly FD) pressure relief valves?
-Shimmed (or deleted) eshaft thermovalve?

kaioken

iTrader: (2)

This motor I just placed in this car has 86,000 original miles. We are also having a tach gauge issue what we are trying to workout. So I can not say what reading I am getting at what range. I do have all emissions removed. I will let you know what the oil pressure is reading at idle.