My oil pressure gauge is pegged...is that bad?

[DenaliAK]

So, I recently had a bunch of work done on the truck. I had several oil leaks and yep, fuel pump went buh-bye. $2300 later, and two extra trips to replace faulty replacement gaskets... ....I finally seem to not be leaking any fluids. After the first fix, the brand new oil filter gasket blew, and we went through 10 quarts of oil in a weekend just keeping it running until we could it to the shop on Monday.

Anyway...I got totally side-tracked by being all annoyed about this again...

Finally, no leaks. Things seem tight, running smooth and not stalling thanks to a new fuel pump. Great. For that much money, it damn well better work right. Today I noticed that the oil pressure gauge is as high as it can go. And it doesn't move. Not knowing much about this sort of thing, my first thought was, "that can't be good," but the manual says the only time it's not considered normal and is considered bad is if the pressure gets too low. Definitely not the case here, but I've never seen that gauge read that high, it's usually right in the middle.

Long question short: Is this good, bad, or does it matter? Can I stop worrying about it or should I go back to the shop for the 4th time and probably lose it while there?

 

[Gzes]

Mine was high after my overhaul and went down to the middle after a while. As long as its not low its good

 

[Freedom Motorsports]

IF it stays there and doesn't move at all, even after a few days of driving, I would point to one of two things being bad. Either the oil pressure sending unit, or the stepper motor in the cluster itself. The stepper motors are known for going bad.

Hope you figure it out.

 

[Rivieraracing]

If it was my truck, it would bug me too much to drive it like that without knowing what was going on!! Take it somewhere and have them check the oil pressure mechanically to see how it compares to the cluster gauge! Like mentioned, it's either the stepper motor if yours is 03 and newer or its the sending unit!

 

[WHITEOUT]

I agree, would want to get it checked, like said probably not a big deal just sending unit or stepper motor, as we know those motors just go weird outta nowhere. But, high oil pressure isn't good either. Not saying anything is wrong, but check this site:
http://lubricants.s5.com/oil_pressure.htm

Would personally get it checked out, especially if oil related work was just performed, and nothing with gauge got messed with. IMO, worth getting looked at.

 

[Freedom Motorsports]

Another thing to check right off the bat that I didn't think of before for some reason, check the oil level itself. I know it sounds simple, but when having oil issues like you explained, it is real easy to overfill the crankcase by which causing higher oil pressure as well. This is BAD, so make sure the level is right where it should be and not overfilled.

 

[Kman]

The oil gauges on the GMT800 platforms are known to go bad (mainly the sensor), thus causing them to be pegged past 80 PSI. Too high of oil pressure is bad as seals will be blown.

Your best bet it check the oil pressure sensor and see if it needs to be replaced. There could be a loose wire somewhere also since you did say you had some work done.

Take a look here:
http://www.justanswer.com/chevy/2lhen-oil-pressure-gauge-pegged-maximum-time-ignition.html


Also, what does your oil level look like? Filled to the top? Over filled?

 

[Richard in Reno]

Just diagnosed and fixed a faulty Oil Pressure Sensor Sender:

Indication that your Oil Pressure Sensor Sender is broken:
- Key off - Oil pressure reads 0
- Key in accessory position - Oil pressure reads 80
- Engine running - Oil pressure reads 80 and does not change

To confirm Oil Pressure Sensor Sender is faulty (and not the gauge), remove the wire from the oil pressure sensor sender:
- Key off - Oil pressure reads 0
- Key in accessory position - Oil pressure reads 0
- Engine running - Oil pressure reads 0

Proper operation:
- Key off - Oil pressure reads 0
- Key on accessory position - Oil pressure reads 0
- Engine running - Oil pressure reads 60 and changes as I rev the engine

 

[new2yukon]

I need help on this oil gauge issue...

Previous
-- Pressure read zero with key on, engine off.
-- Pressure stuck 40 range with engine running and stays there when turned off.
-- Needle jerky, never smooth.

Then...
-- New Standard Motor Prod sensor yielded same results as above.

Now...
-- New stepper motor totally changes things. Gets 80psi whether running or not. Slightly higher accelerating.
-- Doesn't zero out at all. Not ever.
-- Unplugging sensor yields 80 with key on and even WAY higher psi running, never reads zero. Moves smoothly doesn't seem to stick even though high psi readings.

Put in old sensor and get same results as with the new std motor prod sensor. It never zeros out and tends to stay at 80.

Could both sensors really be bad?

Thanks for any help!

 

[DenaliAK]

Mine quit *******, and now it jumps all over the place. Zero to all over. The stupid low pressure alarm goes off all the time and is super annoying. Mechanic said it's the sending unit (again) but haven't had time or money to fix it yet.

 

[new2yukon]

So...The sending units are that unreliable?? My replacement new one didn't solve it either so I GUESS I have 2 issues? The sender and the stepper?

So. Another sender unit is likely my solution?

Oh..and one more thing...threads on my SMP replacement were longer than the one in there so didn't tighten down to a good seal. But even the one in there didnt, either. I get a leak around there, too. Ughhhhh..acdelco will have to be my next gamble.

 

[DenaliAK]

So...The sending units are that unreliable?? My replacement new one didn't solve it either so I GUESS I have 2 issues? The sender and the stepper?

So. Another sender unit is likely my solution?

Oh..and one more thing...threads on my SMP replacement were longer than the one in there so didn't tighten down to a good seal. But even the one in there didnt, either. I get a leak around there, too. Ughhhhh..acdelco will have to be my next gamble.

Yeah, I've also gone through two fuel pumps in 5 years. Stupid design, requires a ton of work to replace, so even though the part is under warranty it still costs a few hundred in labor for the fuel pump replacement. [emoji35]

 

[new2yukon]

So do you feel the sender should fix it? Gosh I hate to buy it just to guess but I know of nothing else. The new stepper doesn't jerk and skip so maybe it's working ok.

 

[DenaliAK]

I'm not sure. When I have a question I take it in for an estimate. Most places don't charge for an estimate and tell you what they think is wrong.

 

[HiHoeSilver]

Use AC Delco unit only. The aftermarket ones are notorious for problems. It's a $20 part that's takes 30 minutes to replace.

 

[new2yukon]

Hehe. Getting good at pulling this sensor. WIll put in an ACcdelco sensor and see what happens. Getting gun shy with this sensor issue.

 

[D is for DENALI]

as everyone said, always buy ac Delco or oe brand replacement.

I changed my unit when I bought it, it tough if you have fat hands and are not flexible... you need to come from the topside and go behind the engine... y pu also need a special THIN well socket so it fits in the small space provided.

This will be frustrating the first time, as its mostly a blind fix, not being able to see what you are doing.
lots of reaching down and 'feeling'...

after new ac delco unit, it should be fine, if not, go to the stepper motor.

Also make sure your oil level is perfect!!!

 

[new2yukon]

I've got all my parts and stuff to install a secondary aftermarket electrical pressure gauge. The stock one still has issues and no matter what gets resolved in it I will have the new one as well which will be tee off the pressure port

My only hiccup right now is how to get switched power that turns on and off with the key turn.

Any assistance in this area?

 

[PG01]

Under the steering column is the on the firewall there is a black cover pop that and youll expose many large plug ins.... there should be an empty spot with male spade terms sticking up or female... i forget but eitherway you have switched, constant, rap, ground...all kinds of shit there ill try to find a pic

 

[new2yukon]

I'm checking in to that. Just yesterday I learned of these add a curcuit, piggyback fuse things which now totally simplifies my issue. Didn't know they were made...stumbled into it on the internet.

You don't know what you don't know!! )