low oil pressure

[wx3rob]

I just had an oil change last week and I noticed that it has been had starting. Yesterday it was even worse. I had 30# pressure on idle and 40 on acceleration. THEN all of sudden it dropped to 0 and I lost power (20mph max). Pulled into the drive way and let it sit overnight.
This morning I checked the oil and had plenty (actually over full a little). I started it and had 30/40 (normal). Then it started dropping slowly. I immediately shut it down. Is it a bad pickup, switch or pump?

 

[Sheriff]

The first thing you need to do is check and make sure whoever changed your oil used an OEM Delco oil filter. Aftermarket filters such as Fram and Purolater are notorious for causing these problems.

 

[wx3rob]

Thanx Sheriff. I just looked at the filter and didn't see any markings on it. This garage has done oil changes for me before and never had a problem. <??>

 

[2007tahoe]

Thanx Sheriff. I just looked at the filter and didn't see any markings on it. This garage has done oil changes for me before and never had a problem. <??>

The garage didn't make the filter. I have worked at shops and have seen 2 different trucks ruin the eng because a brand new bad oil filter. What year is your truck, miles, ect. I Could be the pump, gauge, or the gauge sending unit also. I would just go buy a new oil filter and put it on the see what it does since it just happened after an oil change and its full of oil. Sending units are cheap and only take a few min to change. I did the gauge on a 2005 tahoe and it sucks; you have to pull the gauge cluster apart and so on. Start with the easy stuff.

 

[Sheriff]

Thanx Sheriff. I just looked at the filter and didn't see any markings on it. This garage has done oil changes for me before and never had a problem. <??>

An original equipment oil filter by AC Delco should be blue.

 

[GM Customer Service]

wx3rob,

I am sorry to hear that you are experiencing this issue. Did you find out if you did indeed have the proper oil filter? Also, did you let the service shop know what is going on with your vehicle since they did your oil change?

Thank you,

Elizabeth, GM Customer Service

 

[Dave_2003_TRZ06]

You could have a failing oil pump, or worn main/rod bearings, this would be worst case scenario... Did you hear any clatter from the engine/valvetrain/lifters? Things tend to get noisy when starved for oil. Possible that it is the sending unit, but that does not explain the loss of power. You could start with dropping the filter and going with an OEM or better like Mobil1 filter, then topping off the oil and keeping an eye on things.

 

[SmallXL]

if it was overfilled your crank could be spinning into the oil and aerating it. That will cause a drop in pressure.

 

[Millsp]

I have the same problem with my oil pressure, i just got it changed and the only time it will go over 40 is when im accelerating at high speeds

 

[Grocery Getter]

Had the same issue on my 04' a while back...... most likely it's the oil pressure sending unit. My second guess is the stepper motor........all the things mebtioned by the others are certainly possible but I think it's the sending unit..........it's a bugger to get to but I did mine myself, $50 for sending unit and special socet and about an hour to swap it out due to the placement of it on th back of the block..........