44fore

i realize that this has probably already been discussed here, but after a search i could not find a posting on it.. sorry if duplicate..

Vehicle - 2007 Impala LTZ, 3900 series (3.9L V6), 192,000 miles.

This is my wife's daily driver, and it gets alot of Highway miles obviously. We keep the maintenance up on it - oil changes every 3000 miles, brakes, fluid and filter changes, tires, alignments, etc.. sometimes 2 oil changes a month including a new filter every time, and full synthetic oil since 75,000..

we have had two issues with the car, both of which we believe inherent to this model impala - 1 large evap leak code due to faulty sensor, and now 2) LOW OIL PRESSURE STOP ENGINE light coming on..

details on Low Oil Pressure light - it initially was just a flicker here and there, and i mean a flicker - you could tell something changed on dash read out, but could not catch the flicker in time to see what it was for sure. Then it began to stay on for short periods of time, and was intermittent - this could be shut off by either accelerating or braking (change momentum) or shut off and allow engine to cool.. Seemed worse the warmer the engine got, or climbing a lot of hills on interstate. Yesterday my wife said it stayed on for 15 minutes at last part of drive home. This morning i cannot duplicate or get light to come on.

What we have done to try to remedy this issue - Had Oil Pressure Switch (Sensor) replaced at area near top of Oil Filter, had car checked for codes and reset to try to clear anything, Changed oil and filter twice since started - even before mileage time frame., Also had wiring at sensor checked, and nothing found. A mechanical gauge was screwed into port that the sensor goes into and no abnormal pressures or fluctuations were found.

Mechanics are stumped and the car still drives/runs great, no noises, misses, or loss of power to speak of. Car does not leak any oil, or appear to consume any between oil changes, as well no smoke from exhaust either.

Any suggestions of where to go from here? or What we can check is appreciated.. Thank you.

EinST

Are you saying the oil pressure light AND "OIL PRESSURE LOW STOP ENGINE" DIC message are coming on at the same time? If so, it's possible that the oil is not making it back to the sump for some reason. The drain passages are probably blocked by crud somewhere and the oil is pooling under the valve covers.

44fore

The "Oil Pressure Low Stop Engine" DIC message is what we have been noticing.. but the other day the red oil symbol also came on.. this was the first time seeing the red oil symbol light on with the DIC message.. Oil level has been checked numerous times throughout this process and always in good range..

This DIC message has been coming on and off for over 3 months now.. it is beginning to stay on longer periods of time now.. it has been to both the dealer on multiple occasions and now an independent mechanic shop, and no one seems to have an answer or fix.. The last suggestion was a "Instrument Cluster" replacement?? figured id ask here to see if anyone had further ideas or suggestions to check/repair..

I'm looking to get a new 2500HD for me, and replace the 97 K1500 with 376,000 miles.. but I am trying to fix my wife's impala first, and hopefully not replace it and knock my new truck out of the picture for a couple more years.. lol..

EinST

I/P cluster? Can these guys spell C-L-U-E? The PCM turns on the oil pressure light when the oil pressure sensor registers low. For the "OIL PRESSURE LOW STOP ENGINE" DIC message, it goes by the state of the oil level switch on the oil pan. It's not likely they both go and thus chances are you don't have enough oil in the sump during these incidents. If you don't want to commit to the expense of inspecting under the valve covers, try changing the oil with Pennzoil Ultra 5W-20 which is arguably the best high detergent engine oil on the market. Hopefully it'll dissolve whatever the sludge that's the culprit. Mind, the choice of 5W-20 is intentional since it flows better.

P.S. I take that "OIL PRESSURE LOW STOP ENGINE" message blurb back. It's the "ENGINE OIL LOW ADD OIL" message that's tied to the oil level switch. Still, the I/P cluster logic cannot invent the warning light and DIC message and otherwise operate correctly.

44fore

Right. It is NOT the low oil message as in the volume of oil in engine.. it is the low pressure message as in not enough pressure.. never had the low oil volume message, and never checked the level manually and found it low either...

As for the Cluster needing replaced, i was a little concerned about shelling out that money on a guess basically..
thanks for the help.

44fore

Update-
Drove the car yesterday for about 45 minutes, and 30minutes into drive Low Pressure message came on again.. Stopped at chevy dealer and shut car off, when car was restarted no message and no message for return trip home.
This morning my wife went to work (about 2 hr drive) about 35 minutes into drive message came back on, she stopped at a gas station, shut off car, went into store, came out and restarted car, no message now, and finished her drive to work without the message reappearing. Again - all these times there is no strange sounds, no loss of power, and no operating issues.

My intention is to change the oil tonight when she gets home and use the Pennzoil recommendation from EinST above.. but i was wondering if anyone thought there would be any benefit from putting in a oil/engine flush additive to the current oil, allowing it to come to operating temperature, then changing oil to the Pennzoil? If ths is a benefit, does anyone have a recommendation on a good flush to add in (ie. seafoam, marvel, etc.)?

one last question - does the filter housing or adapter, where the Oil filter screws onto, remove easily without having to tear down major engine components? I was thinking that while the filter is off, maybe take this adapter off and clean the port where the pressure sensor sits above the filter. It all appears to be a bolted on aluminum adapter that allows for the pressure sensor/switch and oil filter to be attached to the engine..

thanks.

Karen Peterson

Hi igot the same issue. But I also get the ringing bell to stop engine. How did this issue turnout

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]--> Karen Peterson and 44fore,

The valve lifter oil filter may need to be inspected for possible debris/sludge that could restrict oil flow to the oil pressure sensor. This is just a suggestion, not a diagnosis. Karen Peterson, I encourage you to have the vehicle inspected by your certified technician.

Louis
GM Customer Service

44fore

Update- after manual oil pressure checks, sensor replacement,sensor wiring checks the message was still randomly coming on.. A friend and GM certified mechanic who had been helping with this suggestion made one final suggestion to try to fix.. The suggestion was to add 8-12 oz of marvel mystery oil additive, I had no clue but needed something to work.. So I followed the directions he gave- add the oil additive, leave in for 50-100 miles, then change oil (while warm as I always have. Noticed message less and less as neared 100 miles. Changed oil and since then only had the message twice, both times right at morning start up, shut engine off and restarted, and no message.. Vehicle still runs fine, no ses lights or messages, and now 198,000 miles..

EinST

Congrats and thanks for the update.