Low Oil Pressure / Oil Pressure Switch

[tbgrey2007]

I'm having the low oil pressure that throws the code. Cold pressure is around 20. It will go up to around 40 at highway speeds after it is warm, but seems to bounce around a lot. The oil pressure switch has been checked and I believe they just left the screen out that sits underneath. I don't know if the low pressure at start and the fluctuations are symptoms of it sucking air, like maybe the oil ring on the pick-up line or something else. I've seen the comments and videos on doing an engine flush and chaning that oil ring. I do seem to experience the intermittent lifter tick more often now. Related? Engine has 235k and got a new tranny a few thousand miles ago, so at what point do I just swap the motor out rather than all these band-aids?

 

[avalonandl]

You need to pull the pan and replace the oil pick up tube oring.

At worst a new oil pump.

 

[Geotrash]

I'm having the low oil pressure that throws the code. Cold pressure is around 20. It will go up to around 40 at highway speeds after it is warm, but seems to bounce around a lot. The oil pressure switch has been checked and I believe they just left the screen out that sits underneath. I don't know if the low pressure at start and the fluctuations are symptoms of it sucking air, like maybe the oil ring on the pick-up line or something else. I've seen the comments and videos on doing an engine flush and chaning that oil ring. I do seem to experience the intermittent lifter tick more often now. Related? Engine has 235k and got a new tranny a few thousand miles ago, so at what point do I just swap the motor out rather than all these band-aids?

The sensor was checked or was it replaced? Also, it needs the screen to remain in place if you have AFM active.

235K is nothing if it's been maintained well. Year, model would help.

But to answer your question, the behavior you describe is consistent with what we see with a leaking o-ring.

 

[tbgrey2007]

The sensor was checked or was it replaced? Also, it needs the screen to remain in place if you have AFM active.

235K is nothing if it's been maintained well. Year, model would help.

But to answer your question, the behavior you describe is consistent with what we see with a leaking o-ring.

Thanks for the input. The sensor was replaced several months ago and rechecked when I got the first error code. I'm pretty sure they left the screen out. I have an appointment later this week. The overall pressure has dropped in the last few weeks, which is why I'm taking it in. I did not know the screen was need with the AFM, which is active on the vehicle. 2007 Tahoe LTZ

 

[Vint91]

Just make sure if you do an engine flush that all of your lines leading to the transmission are in very good working order. A mechanic did an engine flush on my Suburban with 215,00 miles to try to unstick a stuck lifter on my suburban, and he blew my new transmission, without replacing the corroded lines first.

 

[Geotrash]

Just make sure if you do an engine flush that all of your lines leading to the transmission are in very good working order. A mechanic did an engine flush on my Suburban with 215,00 miles to try to unstick a stuck lifter on my suburban, and he blew my new transmission, without replacing the corroded lines first.

I don't understand how/why that would happen. The fluid cooling circuit for the transmission is completely separate from the engine oil. Can you elaborate, or better yet, start a different thread so this one doesn't get hijacked?

 

[Vint91]

Sure

 

[tbgrey2007]

Just make sure if you do an engine flush that all of your lines leading to the transmission are in very good working order. A mechanic did an engine flush on my Suburban with 215,00 miles to try to unstick a stuck lifter on my suburban, and he blew my new transmission, without replacing the corroded lines first.

I was thinking more along the lines of the additive as the engine flush. That is mostly what I have seen mentioned here and Youtube videos. interesting that would occur with the transmission. This shop the transmission in a few months ago when trying to solve for my ECM problem.

 

[swathdiver]

I'm having the low oil pressure that throws the code. Cold pressure is around 20. It will go up to around 40 at highway speeds after it is warm, but seems to bounce around a lot. The oil pressure switch has been checked and I believe they just left the screen out that sits underneath. I don't know if the low pressure at start and the fluctuations are symptoms of it sucking air, like maybe the oil ring on the pick-up line or something else. I've seen the comments and videos on doing an engine flush and chaning that oil ring. I do seem to experience the intermittent lifter tick more often now. Related? Engine has 235k and got a new tranny a few thousand miles ago, so at what point do I just swap the motor out rather than all these band-aids?

"Flushing" the engine usually results in sludge and deposits breaking loose and making things worse by clogging up AFM passages. There is a reason GM recommends against this.

If you add 2 quarts to the motor and go for a drive and the pressure stays up then you have your answer on the o-ring.