Anyone Have An Oil Pressure Sensor Fail?

Along with the idiot light or lights..
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Mine failed last year (luckily near my home).
I panicked and parked the car. Went home on foot to pick up my pressure tester. Engine held 45psi oil pressure at idle...
I’m currently installing an electric pressure gauge on top of the idiot light for peace of mind...
 
And it scared me worse than anything I had ever done in a car. Was in a bad Atlanta neighborhood and did not have a phone to call a wrecker.

“Down in the part of town where when you hit a red light you don't stop”
 
Had an issue with the oil idiot lamp going on after a hard acceleration or stop. Checked oil and it was low. But i did not stop the engine, it just take a second until it went out. Do you think that can ruin the engine ? What would you do in this Situation ?
 
I just replaced the oil pressure sensor in my '72 Newport. It was puking oil every time I parked it in the driveway and based on where the oil was coming from, I thought it was the rear main seal. $25 later, it stopped leaking completely. And that was with buying the special socket. My point, swap it out and see if it helps.

Also, I had the oil light come on about a month after I bought it during hard stops. It had a few oil leaks after sitting for a few decades that I hadn't addressed yet. I played the game of topping it off when the oil light started coming on when I stopped in the fall before it went into storage for the winter (and I replaced gaskets to seal it up). Runs like a top now but I can't imagine doing that long-term would be a good idea.
 
the oil light on when the engine is running is never good, but a flicker or second of it being on in a panic stop isn't going to kill an engine. I custom baffled my pan as my Fury would uncover the pickup on launch and flicker the light at higher rpm, a way worse situation that never ruined the engine. I'm sure it took a few thousand miles of life off the bearings though!

The advice on the drydock was always to run 6qt in the 5qt pan, that definitely helps the slosh.
 
The other day I took the 1972 Newport out for a drive. The oil pressure light came on. I immediately stopped the engine. The dipstick showed nearly full, but I added another quart of oil. Started it back up, and the same thing happened. Poured in another quart of oil.

Turned the engine on, and got another warning light. But the engine did not overheat, and ran fine. Put the car on the expressway and drove it home.

Figured there could have been only two things happen- the oil pressure sensor failed or the oil pump failed. The oil pump was replaced on the engine rebuild. Since the engine didn't seize on the drive home, I figured it must be a faulty sensor. Anyone else have any other ideas what may have caused it? If the wire came loose would that cause the light to come on.

Where is the oil pressure sensor on the 400 B-block engine, by the way.
when u have a oil light that comes on it means the oil pressure has dropped below 15-20 # it dose not mean u r out of oil or it needs to be changed . u have a serious problem . what happens most of the time the sensor spring is week( in the idiot light sensor is a metal plate & a spring with the pressure drops lower than 15-20# the plate grounds turning on the light ) stopping was a good idea but adding a qt of oil to a full system was not . u should had it towed home or to yur shop yo have it checked to c if it had oil pressure , more in likely it was a bad censor. but drive a car with the light on & not knowing if u had oil pressure is very dangerous u could had damaged the 400 . that is y i don't use lights but mechanical gauge that way i can check the pressure @ a glance
 
when u have a oil light that comes on it means the oil pressure has dropped below 15-20 # it dose not mean u r out of oil or it needs to be changed . u have a serious problem . what happens most of the time the sensor spring is week( in the idiot light sensor is a metal plate & a spring with the pressure drops lower than 15-20# the plate grounds turning on the light ) stopping was a good idea but adding a qt of oil to a full system was not . u should had it towed home or to yur shop yo have it checked to c if it had oil pressure , more in likely it was a bad censor. but drive a car with the light on & not knowing if u had oil pressure is very dangerous u could had damaged the 400 . that is y i don't use lights but mechanical gauge that way i can check the pressure @ a glance
I think the pressure is closer to under 5 PSI if and when the light turns on. Probably around 2 or 3 psi from what I remember reading. I like a gauge better also but many people don't look at their gauges as often as I do.
 
Guys, you can get a cheap mechanical oil pressure gauge for $30, or a damned good Stewart Warner one for $50-100, depending on what you like in it. I got a cheap mech gauge the second day I owned Mathilda, and have been happy I did. So long as you have 20 psi at idle, you're in decent shape. You can TELL when you have NO oil pressure. 1.) The lifters will clatter loudly. That's the time to STOP THAT ENGINE AND SOLVE THE PROBLEM!

2.) I've not abused any Mopar engine to this point, but connecting rods will start knocking if you're fool enough to keep running the engine with no oil pressure. If you persist in running it after this, you needn't worry for long, except about where to put a 600 lb paperweight.

I had the pressure relief valve fail on my old oil pump the first few months I had Tilly, but after popping it loose, noticing some small crud that may have blocked or stopped it, I put it back in and the oil pressure came back. I also had a problem with losing the prime on the pump after changing the oil. I bought a nice new Melling pump and switched from 10W40 to 10W30 viscosity oil and have had no further trouble with losing the prime on an oil change or any other time. I changed from K & N filters to Wix at the same time.

Again, GET A MECHANICAL GAUGE!!! They rely on no other system but a little plumbing to give you reasonably accurate to VERY accurate estimates of engine oil pressure. You can plumb a tee in on the back of that block where the sending unit goes and run your idiot light electric switch AND a mech gauge, or an electric gauge even, but trust the mech gauge first. By the time the red idiot light goes on, you have UNDER 3-5 PSI left of oil pressure. These B/RB engines are INCREDIBLY tough, but enough stupidity will destroy even these.
 
Sorry to thread jack, but I'm in the process of adding an after mark oil pressuregauge. How in the heck do I remove the sender? Its a dummy light sender BTW. Also, how to remove the passenger side one that is a block plug.

Thanks guys!
 
Mine failed last year (luckily near my home).
I panicked and parked the car. Went home on foot to pick up my pressure tester. Engine held 45psi oil pressure at idle...
I’m currently installing an electric pressure gauge on top of the idiot light for peace of mind...
if the light didnt come on u was safe that is Y the mechanical gauge r the best fot oil pressure most of the lights r set uop for 15# or less but i know what u mean . the way the light is set up there is a 15# soring in the sencer when the pressure falls to 15# or less the plate the spring is connected to grounds turning the light on . but the electric sencers fail all the time c if u can get a oil feed gauge just be sure u dont pinch the plastic line feeding the gauge u may want to up grade the plastic line with a 1/8" copper line they dont break as easy
 
I have always worried about mechanical oil psi gauges and the possibility of a quick oil slick on my carpet ,under dash or hood. I do use a mechanical in my Omni and never had a problem but in my Fury I went to a good quality electric . My idiot oil pressure light works and between the two I can grasp if anything is really wrong.
 
I have always worried about mechanical oil psi gauges and the possibility of a quick oil slick on my carpet ,under dash or hood. I do use a mechanical in my Omni and never had a problem but in my Fury I went to a good quality electric . My idiot oil pressure light works and between the two I can grasp if anything is really wrong.
I have used a mechanical oil pressure gauge and copper 1/8” tubing. I bent a nice ‘s’ shaped strain relief between the adapter and the interior fender liner to reduce the chance of tubing fracture.
 
I have used a mechanical oil pressure gauge and copper 1/8” tubing. I bent a nice ‘s’ shaped strain relief between the adapter and the interior fender liner to reduce the chance of tubing fracture.
Oh, and either a rubber grommet or a bulkhead fitting at the firewall.
 
yeah I was actually planning on going a little different route and route on the exterior near cowl vent( a little unconventional but I've seen some nice set ups)

I've always preferred the accuracy of mechanical over electrical, and don't want an oil spill on new carpet!
 
yeah I was actually planning on going a little different route and route on the exterior near cowl vent( a little unconventional but I've seen some nice set ups)

I've always preferred the accuracy of mechanical over electrical, and don't want an oil spill on new carpet!
Mechanical gauges aren't much more accurate. Another old wive's tale.

If you don't believe me, I stumbled across this: https://www.chevyhardcore.com/tech-stories/other-tech/autometer-gauge-selection/#:~:text=“A typical AutoMeter electronic gauge,-world accuracy, very durable.

As he states in the article, the Autometer electric gauges are +/- 5% at full scale. From my 22 years in the world of gauge calibration, I'll tell you that's about the same as most aftermarket automotive bourdon tube "mechanical" gauges. The higher end Autometer gauges might be better, but most of the gauges you buy aren't.
 
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Had an issue with the oil idiot lamp going on after a hard acceleration or stop. Checked oil and it was low. But i did not stop the engine, it just take a second until it went out. Do you think that can ruin the engine ? What would you do in this Situation ?

The pump can suck the pan dry on hard acceleration if the engine is cold or the oil is low. That results in low or no oil pressure which can be very destructive. Keep your oil level full and be sure the engine is fully warmed up before jumping on on the throttle. On a full sump, a standard oil pump will usually not pull out all the oil, that is more of a problem with high volume pumps or on engines that are badly sludged up.

Dave
 
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