Jump to content

Low oil pressure gauge at Idle make engine coolant hot

Grizzlyghost

Recommended Posts

Podor Enthusiast

Podor

Posted
Posted

So, it sounds like it gets hot enough to turn the warning on and the oil pressure goes low enough to turn the warning light on. That eliminates the stepper motors.

 

I had similar issues on my '05, which were caused by the Castech cracked heads. I don't drive mine during the week, so I don't sit in traffic for it to get too hot. There were a few things that tipped me off. The first thing I noticed was the oil pressure was about 10 psi at idle. I also assumed it was a stepper motor so I didn't pay much attention. I noticed the fans were at high almost immediately after driving, with or without the AC. It never overheated, but no traffic. The final clue was that I would have to add coolant about every 300 miles or so with absolutely no external leaks. I even pressure tested it for several hours and it didn't drop a bit.

 

The oil pressure was caused by the coolant leaking into the oil. Over time, the water evaporated leaving the glycol which diluted the oil wearing the bearings, but didn't cause the oil to be milky. I never saw any evidence on the dipstick. It was getting hot because there were air pockets caused by the cracks.

 

The first thing to check is if the head casting number is 706. On the passenger side head, the casting number will be on the front lower corner, right under the valve cover. If the casting number is 862, it isn't a castech head. If it is 706, you still may not have a bad head. The real way to verify is to remove the valve cover and look for a battery shaped casting mark under the rocker mounts. You'll also find lots of milky residue on the valve cover. See the article below.

 

http://www.agcoauto.com/content/news/p2_articleid

  • 3 weeks later...
Grizzlyghost Enthusiast

Grizzlyghost

Posted
  • Author
Posted

So, it sounds like it gets hot enough to turn the warning on and the oil pressure goes low enough to turn the warning light on. That eliminates the stepper motors.

 

I had similar issues on my '05, which were caused by the Castech cracked heads. I don't drive mine during the week, so I don't sit in traffic for it to get too hot. There were a few things that tipped me off. The first thing I noticed was the oil pressure was about 10 psi at idle. I also assumed it was a stepper motor so I didn't pay much attention. I noticed the fans were at high almost immediately after driving, with or without the AC. It never overheated, but no traffic. The final clue was that I would have to add coolant about every 300 miles or so with absolutely no external leaks. I even pressure tested it for several hours and it didn't drop a bit.

 

The oil pressure was caused by the coolant leaking into the oil. Over time, the water evaporated leaving the glycol which diluted the oil wearing the bearings, but didn't cause the oil to be milky. I never saw any evidence on the dipstick. It was getting hot because there were air pockets caused by the cracks.

 

The first thing to check is if the head casting number is 706. On the passenger side head, the casting number will be on the front lower corner, right under the valve cover. If the casting number is 862, it isn't a castech head. If it is 706, you still may not have a bad head. The real way to verify is to remove the valve cover and look for a battery shaped casting mark under the rocker mounts. You'll also find lots of milky residue on the valve cover. See the article below

http://www.agcoauto.com/content/news/p2_articleid

kind of hard to find the casting head number but as i see in my truck, im not losing any coolant, over time engine oil will burn off and i refill as needed, i couldn't click the article link doesnt work, and yeah my oil isnt milky nor is anything smoking out the pipe... i dont know where the valve cover maybe a picture description would be better. but thank again...

Grizzlyghost Enthusiast

Grizzlyghost

Posted
  • Author
Posted

im still driving the truck and if i start it up it start fine then after 5-10min it would start to go down the oil pressure guage... if i be driving in the neighborhood with lot of stop and go slow driving, it will get hot on me with low oil pressure showing at 10 psi then when i rev my engine while at netural, it goes back up to normal... still i couldnt find anything making it hot... what could it be...

Grizzlyghost Enthusiast

Grizzlyghost

Posted
  • Author
Posted

finally found out had bad oil pump causing low oil pressure guage then my radiator was going out... got a new truck and it much much better...

dhmtbiker9 Enthusiast

dhmtbiker9

Posted
Posted

The heating up started after the thermostat replacement, did it run hot before the work done?could be bad thermostat

Archived

This topic is now archived and is closed to further replies.

Go to topic listing

  • Latest Articles

  • Posts

    • Atlas
      Gas Prices

      By Atlas · Posted

      Welcome back! No, it definitely doesn't pass the sniff test. Even "ceasefire" needs an alternative definition these days.    $5.29 at Kroger today
    • bluev8
      Intermittent no-code issues on 2022.5+ V8 trucks — what did the shop fail to capture?

      By bluev8 · Posted

      That makes sense, and I think you are describing the real product problem. Capturing data is the easy part. If the owner or technician has to manually dig through five minutes of millisecond-level logs, the product has already failed. The device would be at the ECM harness, not at the OBD port, so I agree that data retrieval and event marking need to be thought through carefully. The way I am thinking about the architecture is: The recorder itself should not depend on a phone, app, Bluetooth, Wi-Fi, or cloud connection to capture the event. It should always keep a local rolling buffer and lock the event locally. A button, phone app, or small cabin device would only act as an event marker. If the driver feels a stumble and presses the button 10–30 seconds later, the pre-buffer has to already contain the useful data. For data retrieval, the practical options would be a sealed service USB lead, Wi-Fi download, or a phone/cabin companion device. I would not expect the owner to remove the ECM-side module or work with raw files directly. The cloud or AI side would be for interpretation, not for capturing the event. The truck may have no connection when the issue happens, so the evidence has to be saved locally first. After that, cloud processing could help decode the data, compare it against baselines, and generate a readable report. For the first version, I would keep the automatic triggers conservative and objective: driver event marker bus-off error passive voltage drop / brownout device reset FIFO or queue overflow a normally periodic message disappearing side-to-side communication mismatch, if the topology supports that For “learning normal,” I agree with your point, but I would not want to overclaim it as automatic root-cause diagnosis at first. A realistic first step would be learned baseline comparison for that specific vehicle and operating condition. For example, a value would only be compared against similar conditions: RPM range load / MAP throttle position gear / vehicle speed coolant and oil temperature battery voltage AFM/DFM state, if decoded and validated Then the report could flag things like: this periodic message disappeared compared with its normal timing this value deviated from this vehicle’s normal range under similar conditions the same abnormal pattern repeated after the same type of event the anomaly occurred together with voltage, oil-pressure, misfire, or communication changes But I would still call that “abnormal pattern detected,” not “replace this part,” unless there is enough validated repair data behind it. So the intended product would not be “here is a huge log.” It would need to be an event package: what triggered the capture how much pre/post data was preserved what changed before and after the event whether the device itself reset, overflowed, or saw a bus error selected graphs around the event raw data only as supporting evidence From your perspective, what would make this kind of report useful instead of just another datalog? For example: What are the top 5 parameters or events you would want highlighted first? Would you trust a learned baseline for that specific vehicle, or would you prefer fixed thresholds? How much false-positive flagging would be acceptable before you stopped looking at the reports? What would a one-page report need to show for an independent shop to take it seriously? For misfire, AFM/DFM, oil pressure, or U-code complaints, what would you want the tool to flag automatically?
    • scotthvac.net
      2022-24 halogen - led grille swap

      By scotthvac.net · Posted

      2024 Silverado 2500 HD LTZ grille no camera Parts list   84603331 84913656 84913657 84913654 84913655 84911567 84911568 85646092 85646093 85797921 85797922   11570637  x10-15   grille/bumper bolts 11546500  x10      grille clips 11571006  x10      push/retainer clips 11546454  x6       nut retainers 11611609  x6       M5 bolts 11610700  x6       molding/trim retainers
    • davester
      Replacement Radiator

      By davester · Posted

      And use RA's 5% discount code if you buy from them.  google for the code, one is always available.
    • davester
      Turning radius

      By davester · Posted

      Just don't turn the steering wheel as much?

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...