TWard

I hit the gas on the way home on my 07 Suburban LTZ with 104K miles on it and got a low oil pressure alarm. I didn't pay too much attention to it, but I did listen to the engine carefully for the rest of the ride home (about 10 miles). I pulled over about 1/2 mile from home, shut it off, and restarted it after about a minute. The pressure came up just below 40 and then slowly started down to about 10 as I drove the rest of the way. I checked the oil and I'm up to snuff on the level.

I've read enough here where I suspect a clogged engine oil screen or a faulty sending unit. I've also seen bad ground and shorted wires to cam sensors. Anyone with a similar issue that can chip in on the probable cause?

I'm planning to run some seafoam through the crank case and have the oil changed this week. BTW, what is the normal range on the gauge for oil pressure?

Chevrolet Customer Service

Hey TWard,

I just took a look into your owner's manual on page 238, and this is some information I found regarding the oil pressure; Oil pressure may vary with engine speed, outside
temperature and oil viscosity, but readings above the low pressure zone indicate the normal operating range. When the oil pressure reaches the low pressure zone, the “OIL PRESSURE LOW STOP ENGINE” message will appear in the Driver Information Center. Please let us know what the outcome is after your oil change, and if you have any other questions and concerns. Thanks!

Patsy G
Chevrolet Customer Care

TWard

Put in a quart of seafoam this morning and ran the engine at idle for awhile. The normal pressure (based on other posts) seems to be at around 40- mine was less than 10. Ran a local errand of about 6 miles round trip mid-morning. Truck started at around 40, went up to around 60 when I hit the road and accelerated, and then started coming back down to a sub-20 reading. This afternoon I ran it again at idle. Started at 40 and is starting to hold at that reading.

I'll have it in the dealership Thursday morning for the oil change. They will also look at the check engine light that came on when the pressure went low Monday and the service stable track light that came on at idle this morning!

Now, off to another part of this forum to find out why the speakers in my doors don't play any sound on that great Bose system in the truck!

TWard

Day two of the crank case treatment: Ran into town- 62 miles round trip- Oil pressure started at 42 and ramped up to near 60 when I hit the road. The pressure settled at 40 while I had the cruise at 60 mph, except when the engine went from 8 to 4 cylinder mode, where the oil pressure shot up 10-15 psi. The pressure pretty much held to 35 psi or higher for the entire trip. Oil change tomorrow morning.

a454elk

My 09 Sierra did the same exact thing. I removed the oil pressure sensor, thanks to advice here, and cleared the screen. Working fine since, runs around 40 all the time, no issues and no warning light.

TWard

So, what did you do to clear the screen? Can you share your method and process, and any difficulty you ran into?

TWard

Back from the Dealer...........Ran the truck in this morning. Started fine and pressure over 40, pressure ramped up to just below 60 at hiway speeds. But by the time I got 18 miles down the road, the pressure was hanging around 20 and bouncing about 5psi up. Dealer replaced the oil/filter with synthetic. I asked what the oil looked like because before I put in the seafoam, it looked pretty good. I was told it came out almost black. The dealer confirmed that the valve screen gets clogged and only occasionally they get a bad sending unit. But the dealer said that the valve screen can re-clog, and told me to keep an eye on it.

Got in the truck and started it- pressure was just shy of 60 and stayed between 40 and 60 the whole way. BTW, in an earlier post I mentioned the pressure shot up 10-15 psi when the engine went to 4 cylinders. After the oil change there was no change in the pressure when the vehicle went back and forth from 8 to 4 to 8 cylinders.

I'm going to try and run the truck 2000 miles, seafoam it and then get the oil changed again. Since this truck is new to me, and I'm not sure how well it was taken care of, I'm going to assume it needs a little extra love.

a454elk

I had a code reader from a friend and it allowed me to clear the error code. My sensor was ok, it was just the screen and it wasn't any problem clearing the code. The pressure ran about 40 and never went above that.

tech2

replace the screen and sensor.

Joe In NY

I would switch to Mobil 1 and stay. It takes great care of the motors internals. It keeps it clean and lasts a while.. Also, its on sale all the time at the auto stores!

Seafoam is not as helpful as you may think. And any type of cleaner you put in your oil, change your oil immediately following, you are asking for trouble if you try to drive with it, just think:

Built up debree is freed by powerful cleaner, it now falls to bottom of sump and gets sucked up by the oil pump, now its blocking up the sump screen, and also you get plenty of small bits that get past and start to fill up your filter. Now your pump can't pump the proper amount of oil and the powerful cleaner thins the oil severely. This is bad for many things. Its bad because it doesn't lubricate the rings like it should so you will start scoring the cylinders, the bearing now do not receive a nice thick oil that stays around for a bit with friction modifiers, instead it quickly leaves and leads quick bearing failure, lastly, because its thin and now your oil pump is struggling because of debree, the thinner oil tends to leave the oil system quicker and it doesn't want to go to the heads as it should, so now your rocker arms aren't receiving proper oil...

You have to be careful with oil cleaners. My friend had his Dodge Hemi full serviced at Valvoline because it just hit 100K at the time. They "upgraded" him to Synthetic for free. Well, they put in synthetic with a powerful cleaner and for the trucks whole life prior it had run regular conventional oil. Well after a 30 min trip on way, stop, start and return, his oil pressure dropped to 0. Stopped, check the oil, it was fine, started, there was pressure, cont'd. Went to 0 again after a few mile, repeat... Finally got home, with some noisy lifters, dropped the pan, and crap. Literally, all the built up crap in the motor got flushed by the oil into the pan and it completely clogged his oil sump screen and oil filter. Every-time he stopped the sludge felll to the bottom and after a bit of driving would then get sucked up and re-clog the screen... So, he traded it in with a shot Hemi motor (poor thing)