Oil Pressure Sensor Keeps Failing with Oil Leak

[OutandAbout]

I need some help with this. 2005 Tahoe Z71 with the 5.3 gas. I am on my 4th oil pressure sensor in 3 years, second in the last 4 months. Same problem each time, oil leak at the sensor connector. Oil is inside where the pigtail plugs in. I notice the small spots on the floor first. Eventually the gauge starts to misread due to the oil in the connector/pigtail. I have been replacing them with ACDelco PN 12677836 and I have the correct socket. There is no screen that I can see or am aware of on this engine below the sensor. It is not leaking around the threads, it is inside the connector.

Either I am doing something wrong when I replace them, something else is causing the same failure across multiple parts, or the parts are just crap. Anyone else experience this? HELP?

 

[Fless]

There shouldn't be a screen on an '05; that's for AFM engines.

Has one of the sensors contaminated the wire connector, pushing oil into the wiring, and oil is possibly leaking back to the connector from the wiring? Might consider replacing the pigtail and a section of the wiring if that's the case.

 

[OutandAbout]

There shouldn't be a screen on an '05; that's for AFM engines.

Has one of the sensors contaminated the wire connector, pushing oil into the wiring, and oil is possibly leaking back to the connector from the wiring? Might consider replacing the pigtail and a section of the wiring if that's the case.

Maybe possible but the last one I put in was November and I sprayed the connector with cleaner and let is dry overnight.

The oil spots showed up again last week. Seems like it's enough oil to not be residual from the harness/pigtail but its something I had not considered. I have not ever replaced the pigtail or harness section.

Has anyone had luck with another part number or manufacturer of the oil sensor?

 

[Fless]

Dumb question, but what is the operating oil pressure? Does it ever go high?

 

[mattbta]

Where are you acquiring your Delco part? Amazon is risky for fakes. I use summit or eBay seller partscenterplus (chevy dealer in AZ) when buying sensors.

EDIT: 26 lb ft torque spec

Long shot, too - the cam position sensor is next to the oil pressure sensor and can leak:

 

[Fless]

Where are you acquiring your Delco part? Amazon is risky for fakes. I use summit or eBay seller partscenterplus (chevy dealer in AZ) when buying sensors.

EDIT: 26 lb ft torque spec

Long shot, too - the cam position sensor is next to the oil pressure sensor and can leak:
View attachment 392493

Awesome clear pic!

 

[OR VietVet]

Yes, like @Fless says, no screen. Where are you buying the sensors? So many counterfeits out there.

 

[OutandAbout]

Dumb question, but what is the operating oil pressure? Does it ever go high?

I don't have an external one to test with. According to the cluster gage anyway, I'ld say roughly 30 idle, 40 cruising, 50+ if I'm putting it to the floor and the trans kicks down, then it goes back to around 40. Is that right?

 

[OutandAbout]

Yes, like @Fless says, no screen. Where are you buying the sensors? So many counterfeits out there.

eBay and Amazon. Amazon from the ACDelco store, but sold by a third party. Ebay from Auto-Parts_US Do you think they are counterfeit? I should just get one from the dealer?

I've tried to get part covered on warranty from one seller, and they refused because I installed it myself. The (genuine) AC Delco part 12677836 has a 2 year from purchase, unlimited mile warranty.

 

[mattbta]

Awesome clear pic!

I lifted it from https://www.gmfullsize.com/threads/how-to-change-oil-pressure-sensor.261078/

 

[OutandAbout]

Well, I picked up a legit sensor today from the GM dealer @$101. Due to change the oil in the next couple weeks and will get after it then.

 

[OutandAbout]

Alright, got it done today. Fresh Mobile1 full synthetic high mileage (165K on the Tahoe) with an STP extended life filter. Autozone had a great discount on this package. Back to the new oil pressure sensor from my local GMC dealer. The new one has some differences, mainly the glue around the sensor and metal body, and the angle at the bottom of the sensor.

I'll say though, I took it out to test everything and when I laid into it full kickdown, it was the first time I saw the oil pressure gauge hit 80 in a long time. I have more confidence in this sensor from the dealer already. I think the ones from Amazon and eBay were maybe counterfeit. I'll never know.

 

[OutandAbout]

New part compared to old part. You can see on the new part are some writings and the green dot not present on the old too. The way the PN is written is even different, the font.

 

[OutandAbout]

Is the sensor that is above the oil pressure sensor in this picture the cam position sensor? It had oil residue on the connector when I disconnected it. Cleaned it but maybe its time to replace that also? You can see the funk on the harness to it. Not sure if that from the oil pressure sensor leaking, maybe. I know when the oil pressure sensor fails because I have a couple spots under the Tahoe when its bad. No other leaks that I know of and have replaced multiple top and bottom gaskets in the last couple years.

 

[MassHoe04]

Is the sensor that is above the oil pressure sensor in this picture the cam position sensor? It had oil residue on the connector when I disconnected it. Cleaned it but maybe its time to replace that also? You can see the funk on the harness to it. Not sure if that from the oil pressure sensor leaking, maybe. I know when the oil pressure sensor fails because I have a couple spots under the Tahoe when its bad. No other leaks that I know of and have replaced multiple top and bottom gaskets in the last couple years.

Nothing guarantees a new replacement sensor will be any better than an original. In fact, they can be worse than an oldie.

I would be hesitant to replace a sensor if it is working perfectly now. I've seen too many times, where doing that brings people down a rabbit hole of problems that just have a domino effect.

Clean the connections, reconnect and let it be. That is what I would do.

Correction: I'm not even sure I would disconnect it and clean inside... Spray down and wipe the outside, if the residue is a trigger making you twitch. There is a chance the seal, which as far as anyone knows is still sealing stuff out, might not be as flexible as when it was new and could get damaged when unplugging the connector. If nothing is wrong with it, I would not do a thing to it.

 

[Fless]

Yes, that's the camshaft position sensor.

I would leave it connected and clean the area thoroughly and take a pic as a baseline, then monitor it closely to see if something is still leaking.

If you change the CPS, you may want to have a scanner handy that can do the recommended crankshaft position variation relearn procedure, which is recommended any time the CPS or CKPS is changed.

 

[Blackcar]

You are using deep well socket to install the sensor on the old one looks to have had a open end wrench on it by seeing knick on hex. When using open end, you take a chance in breaking seal on top part of sensor. I would use deep well socket for installing sensor.

 

[OutandAbout]

Yes, that's the camshaft position sensor.

View attachment 393106

I would leave it connected and clean the area thoroughly and take a pic as a baseline, then monitor it closely to see if something is still leaking.

If you change the CPS, you may want to have a scanner handy that can do the recommended crankshaft position variation relearn procedure, which is recommended any time the CPS or CKPS is changed.

I’ll leave it for now but clean it up as recommended and keep an eye on it, pic for baseline. I have a laptop with Tech2Win and TIS2000 I use for it. Recently flashed the ECU TCU and front / rear hvac modules.

 

[OutandAbout]

You are using deep well socket to install the sensor on the old one looks to have had a open end wrench on it by seeing knick on hex. When using open end, you take a chance in breaking seal on top part of sensor. I would use deep well socket for installing sensor.

I have the sensor socket I got from ORiely, the new sensor from GMC felt tighter in the socket. I don’t remove anything when I replace the sensor and use a couple extension with a swivel elbow in between. Made sure to only torque this one to 26 lb ft

 

[Fless]

I’ll leave it for now but clean it up as recommended and keep an eye on it, pic for baseline. I have a laptop with Tech2Win and TIS2000 I use for it. Recently flashed the ECU TCU and front / rear hvac modules.

Curious, when you flashed the modules did you use the ones in TIS2000? Did yours show newer calibrations available, and did you use them?