ITR

iTrader: (1)

Hi guys! Lately, i have noticed that the oil pressure went below the normal level and at times even zero at idle, so i checked the oil level and noticed that it was below the half mark. Then i made an oil change (as it was also due) and started the engine. The oil pressure came back to normal but after that i have accelerated and came back to idle the oil pressure dropped again to zero! But after a while it went back to normal or a bit below. What could it be? (P.s My oil pressure gauge is a stock one. Could it be this?)

Many many thanks in advance!!

VegasFD

Oil pressure sender is failing. My car does the same thing. It doesn't necessarily mean you have low oil pressure. Replace it if you worried about it.

ITR

iTrader: (1)

Thanks VegaFD. Is the oil pressure sender positioned somewhere near the oil filter?

VegasFD

Yes. It's right below it. It's the black thing with the wire clipped into it below the filter. And probably covered with oil. Clean off the connections between the two before you replace
anything.

ITR

iTrader: (1)

Thanks again VegasFD. You've been of great help.

Sgtblue

iTrader: (16)

Go with Vegas' second post first. It likely not the oil pressure sender, just the connection. There's a single wire connector that can get dirty since it's right under the oil filter pedestal. At idle the signal from your sender may be too low to get through a bad/dirty connection, and your guage reads zero. Before you spend ~$100 on a sender, clean it and see what you get.

ITR

iTrader: (1)

Thanks Sgtblue. That's excatly what i'm going to do first. Is there anyone who can show me a picture before please? I just want to make sure that i'll go for the right sensor.

Sgtblue

iTrader: (16)

https://www.rx7club.com/showthread.p...ressure+sender
Located just under the oil filter....can't miss it.
Don't forget to download the Factory Service Manual, it has pics too.

ITR

iTrader: (1)

Sgtblue, thanks. I can't wait to go and check it up. I'm still at work

cesarx7

iTrader: (1)

http://www.clubrx.org/default.asp?id...ntent=50&mnu=5

tphan

this scared the heck out of me when first got the 7...my brother said it has been doing that for 4 yrs...LOL!

cesarx7

iTrader: (1)

Yeah, my oil pressure sender went out a few hours after I bought my FD!! Imagine my shock when I noticed the gauge drop to zero... LOL! Man, I seriously thought I had gotten scammed. Fortunately, I did a little research and found out it was just the sender unit.

Sgtblue

iTrader: (16)

Are you sure it was your sender? I think the vast majority of the time it's just a poor/dirty connection and the weak signal at idle can't get through. Mine fell to zero while idling at operating temps, otherwise "indicated" pressure was fine. I pulled off the connection, cleaned it and stuck it back on and without doing anything else, it worked fine. The senders are pricey, it costs me about $1 for an upgraded female connector and some silicone fusion tape to keep it clean.

cesarx7

iTrader: (1)

That's the first thing I did. I cleaned both ends of the connector with some alcohol, but that didn't work...

VegasFD

I cleaned my connections between the two the best I could, and I'm still having intermittent readouts. It doesn't really bother me though. It's one of those I'd fix if I ever sold the car.

ITR

iTrader: (1)

Many thanks to everyone!! You have really put my mind at rest. I cleaned the connection this weekend but it was invain. When i accelerate i still get the reading right, the probelm is only happeing when idle.

Thanks again!!

xthephilx

Any chance the sensor isn't grounded right? It's kind of a long shot, but try grounding the body of the sensor and seeing if the reading changes.

ITR

iTrader: (1)

Thanks xthephilx, i'll try it and see what happens.

eric e

and don't forget the dodgy gauges mazda used

i recently pulled the inst cluster from a 92 car to repaint it and swapped in another cluster to use while i was doing the painting

without touching the sensor or wiring at all the new cluster's oil pressure gauge showed a much lower reading
remember mazda binned the gauge for a boost gauge later in the FD's life

eric e

pugg57

they went to a boost gauge because the oil sender they use is carp (original) and no one (relatively speaking) ever had oil pressure issues, so it was pretty much a waste of space where as keeping tabs on boost is always important. in all the oil pressure threads i've ever read on here, its always been the sensor or the connector, no one has ever actually proven it was a bad gauge (again, that's the ones i've read, i may have missed a few).

thewird

iTrader: (8)

I kinda use the oil pressure gage to tell when the car is ready to go from a cold start. When it drops below half, the car is ready to go.

thewird

jmadams74

I've cleaned and cleaned! I'm on my 4th sender at 100k miles. They seem to be no good. Wish there were an aftermarket sender that worked with stock guage. Anyway, Ray Crowe had them on special last month at Malloy, I think it was $75? He'll probably still honor it or get you close.