BurbFan

Hi All - I know there have been multiple posts on this one, but I haven't seen any with a recurring problem. Here's my story...

I live in PA, bought the 07 Burb with 105k in MA. As far as I know, the Chevy dealer had changed the oil and installed a Delco filter since the oil looked clean and the oil life indicator said 100% when I picked it up. Started driving home from the dealership. About 60 miles into the drive, got the "Low Oil Pressure - Shut Engine Off" message, and the gauge read near zero. Pulled over and shut down. I had no engine noise before shutting down, so I restarted just to see and the oil pressure was back up to 45. Drove for a few miles and it dropped down again. Restarted and it came back up. Pulled out the Droid and found the posts about bad oil filters. Did the shutdown/restart routine several more times until I got to a place where I could change the oil filter. Replaced the Delco with a Purlolator. Amazingly, oil pressure went back to normal. I figured that was the end of it.

Unfortunately, the problem showed up again the other day. It's been about 1800 miles since replacing the filter. Symptom was exactly the same. I waited until the next day, started and warmed it up. Same problem, except that the pressure never went over about 35. So, today I changed the filter and viola, pressure back to normal. I decided to also go ahead and change the oil this time in case it was contaminated.

It seems very coincidental to me that I would get two bad filters. That said, I have no idea what else it could be that clears up when the filter is changed. Also, I would not call it an intermittent problem, since once it starts it does not resolve itself until the filter is changed. It's kind of critical that I figure this out soon since this is covered by a very short warranty. Thoughts?

Another thing that I noticed is that the oil pressure drops by about 5psi when the system switches to V4 mode. As I understand it, the system diverts oil to the shut down cylinders to disable those lifters, so I'm thinking this slight drop might be normal. Anyone else see this?

Any help would be appreciated!

in2pro

Welcome to the forum...

Give these threads a read and see if they help any...there may be an issue with the sensor that monitors the oil pressure...

https://chevroletforum.com/forum/tah...warning-41924/

https://chevroletforum.com/forum/tah...ocation-39757/

BurbFan

Thanks in2pro. The first link is the one that I found when I was on the side of the highway after the first incident. That's what pointed me to the filter. (Another example of a post saving a reader!)

When it first happened, my first thought was the sending unit since I didn't hear any engine noise. However, I have since decided that this is unlikely for a couple of reasons. First, every pressure sending unit failure I ever had in the past (other vehicles) was either 1) no reading, 2) max reading, or 3) erratic reading. Second, if it was the sending unit, why would changing the filter cause it to return to normal? I'm not saying that it wont be worth checking the pressure with a mechanical guage the next time it happens, but I have a feeling the reading is correct.

I had not seen the second link previously, but I see that one poster in that chain has had this happen multiple times, and the pressure returned each time after changing the oil. I have seen other posts where the light comes on when the oil change monitor gets down to around 15%. I find it hard to believe that this is normal, or that today's filters are that bad. I'm wondering if there is another problem that is just exacerbated as the filter ages?

When I changed the oil, I took a sample that I will have analyzed. Maybe that will provide a clue? Like I said, I have a short warranty on this vehicle, so I want to get this taken care of ASAP, if it's a real problem. I'm fairly certain that the dealership will have no idea what to do if I just take it in and describe the problem.

in2pro

Seems that I recall something about a screen around the sensor that can get clogged or muddied up with dirty oil that can cause the low pressure...you might try a forum search on that as well....

cleveland63b

id take the easy way and bring it back to the dealer...if it happened on your drive home from them they should atleast give it a quick look

73shark

Plus if your warranty is about up, you'll want to get this on the record so they can keep fixing after expiration.

BurbFan

That would be my first choice, if the dealer wasn't 600 miles away! I am on record though, since I notified them after both incidents.

73shark

Would be better to go to any GM service dept. just to get it into their system.

Chevrolet Customer Service

<!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <wontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]--> BurbFan,

Were you able to have the vehicle inspected by your dealer?

Louis
GM Customer Service

BurbFan

Not yet. I have been trying to get a response from the dealer where I purchased the vehicle.