Hi all, here it is Christmas Eve and my truck's oil pressure gauge is sitting on high. I read a post in the old forum that said it could be the oil sensor and there was a nice parts diagram showing where this thing is located on the engine, but I think the pic is for a 6, I'm looking for a pic for the 8 (5.3 97x) if anyone can point me to the right place I would greatly appreciate it. Need to get to the part store in the next hour or so before they close down for Christmas. Hopefully that will solve the problem. The gauge is at zero when it's sitting turned off but when you turn the key it jumps to the other end (high) and once you start it it stays at high.
Oil gauge on High
- Thread starter lesam678
- Start date
My trailblazer just started having a lot of problems, one of them is that the oil pressure is periodically pegged. I has happened twice in the last week and then I let the car sit and then restart the car and let it warm up really well and the problem is gone. Could it be because it is so cold here in Utah right now or should I be worried about a bigger problem.
Welcome! If you fill out the vehicle profile we could help you more accurately. If you have an I6 (we also need the year), the problem is certainly in the gauge cluster, not the engine. Almost certainly a stepper motor, which is the subject of many threads and a how-to article about how to solder in replacements.mdcwell said:
I just update my profile but I have a 2004 trailblazer LS with the inline 6 4x4. I assumed it has to do with a sensor because the car is still running fine. Also even when the car is not started the gauge still reads ust below 80. Any tip on where to find the oil pressure sensor
It's not the sensor. Guaranteed. The gauge should go to zero when off, and if it doesn't, it's a well-known problem with a bad design of early gauge stepper motors. If you can solder, you can replace all six for under $30. If you can't, then Ebay has many vendors for $100-120 to do the job.
The dirty little secret about the I6 engine was GM cheaped out, and the oil pressure sensor is actually a switch. All it does is tell the PCM if there's any sort of oil pressure at all, like 12 or 18 PSI. ON/OFF. The number displayed on the gauge is a total fabrication; a lie made up by the PCM to be "around" 40 PSI, but with slight increases with higher RPM, to fool the non-enthusiast owner into thinking they have a real pressure sensor like the V8 engine has.
The dirty little secret about the I6 engine was GM cheaped out, and the oil pressure sensor is actually a switch. All it does is tell the PCM if there's any sort of oil pressure at all, like 12 or 18 PSI. ON/OFF. The number displayed on the gauge is a total fabrication; a lie made up by the PCM to be "around" 40 PSI, but with slight increases with higher RPM, to fool the non-enthusiast owner into thinking they have a real pressure sensor like the V8 engine has.
the roadie said:
Roadie, I just started having the same problem. I can definitely throw the stepper motors in. Where would you recommend getting them? Thank you!!!!
Read this from the Articles section:
GMTNation - How to change a stepper motor
Then buy the X-27-168 steppers using a search on Ebay or Amazon. LOTS of vendors. Beware the cheap black units, I've heard.
GMTNation - How to change a stepper motor
Then buy the X-27-168 steppers using a search on Ebay or Amazon. LOTS of vendors. Beware the cheap black units, I've heard.
the roadie said:
So, is there a way around this? Like using a V8 sensor and modifying the PCM? In my youth, we used to install mechanical oil pressure gauges to bypass the "idiot lights"
I have a 2006 Saab 9-7x I6.
Can't be done. The issue is the input circuit inside the PCM is different if the sensor is analog or a switch. And that part of the PCM programming has never been hacked. Some members on trailvoy (never read about it here) tried putting an analog sensor in addition to the switch, but if I remember correctly the adapter they had to spin on between the oil filter and the block hits other things in the vicinity. About all anybody can hope to do is put in an analog sensor with a separate gauge like you used to do.ddgm said:
If you do this, please write it up with pictures so we can offer it as a mod for others in the same boat.