Jump to content

Somebody explain how this is healthy for an engine

Jgarner

By Jgarner
in Troubleshooting & Recalls

Recommended Posts

Jgarner Enthusiast

Jgarner

Posted
Posted

I understand they say the oil pressure drops at idle but come on now this is a little much. I feel like I can't take my eye off the gauge like I'm waiting for it to drop to 0. This is driving me insane it's worse when the weather is warm and it hasn't even hit the dead of summer yet. Any tip on a safe way to get some more pressure out of it would be great or if it's normal and it's the same on other trucks. As soon as I drive the pressure rebounds to just below 40psi.post-167394-0-88871600-1490132508_thumb.jpg

post-167394-0-88871600-1490132508_thumb.jpg

post-167394-0-88871600-1490132508_thumb.jpg

post-167394-0-88871600-1490132508_thumb.jpg

  • Replies 35
  • Created
  • Last Reply
DaveH71 Enthusiast

DaveH71

Posted
Posted

Your truck has a two stage oil pump. At idle it enters low stage and drops the oil pressure to around 20 psi to increase engine efficiency. Pump working less = higher efficiency for the engine.

 

Once you start to accelerate the pump returns to high operation mode and increases oil pressure based on RPM and load.

 

6 psi is minimum spec for every 1000rpm for gm. Your truck is fine.

TJay74 Senior Enthusiast

TJay74

Posted
Posted

I would be more worried about running your fuel tank that low than the oil pressure being that low. Hard on fuel pumps as they can tend to run hot when the fuel tank is run low.

trik396 Enthusiast

trik396

Posted
Posted

Your truck has a two stage oil pump. At idle it enters low stage and drops the oil pressure to around 20 psi to increase engine efficiency. Pump working less = higher efficiency for the engine.

 

Once you start to accelerate the pump returns to high operation mode and increases oil pressure based on RPM and load.

 

6 psi is minimum spec for every 1000rpm for gm. Your truck is fine.

I've always heard 10 psi per 1000rpms but either way he is fine
Pacfanweb Enthusiast

Pacfanweb

Posted
Posted

That's plenty of pressure, especially with today's oil.

 

I'd be more concerned about being out of gas. Never run it that low.

Pacfanweb Enthusiast

Pacfanweb

Posted
Posted

 

 

Why? He has plenty of miles left where his gas gage is in that picture.

 

Because it's low, and that uncovers the fuel pump when driving, and THAT leads to shortened fuel pump life.

 

The fuel level isn't about how many miles you have left. You should always consider 1/4 tank "fill up time".

ChevyMan2015 Enthusiast

ChevyMan2015

Posted
Posted

 

Because it's low, and that uncovers the fuel pump when driving, and THAT leads to shortened fuel pump life.

 

The fuel level isn't about how many miles you have left. You should always consider 1/4 tank "fill up time".

 

 

I must have missed this in the owner's manual. Can you tell me what page says to never let the fuel gauge to get below 1/4 tank or it will shorten the life of the fuel pump? Weird, I had no idea.

diyer2 Senior Enthusiast

diyer2

Posted
Posted

 

Because it's low, and that uncovers the fuel pump when driving, and THAT leads to shortened fuel pump life.

 

The fuel level isn't about how many miles you have left. You should always consider 1/4 tank "fill up time".

 

FACT NOT BS I do a half tank then fill. Why wait, your gonna buy it.

 

Oil pressure, volume, gallons per minute is the key IMO. :happysad:

KARNUT Senior Enthusiast

KARNUT

Posted
Posted

I rarely go under 1/2 of tank, sometimes cruising down the HWY a quarter of tank. It's been known for awhile its better for the fuel pump to go 1/2 or better.

Pacfanweb Enthusiast

Pacfanweb

Posted
Posted

 

 

I must have missed this in the owner's manual. Can you tell me what page says to never let the fuel gauge to get below 1/4 tank or it will shorten the life of the fuel pump? Weird, I had no idea.

Does the owner's manual tell you when the change the brakes? Does it tell you when to wash the truck? Does it tell you when your tires are going to wear out? Does it tell you when your transmission is going to fail?

 

It's common knowledge. Run anything with an in-tank pump low a lot and it shortens the life. GM's are known for going through fuel pumps. This is one way to extend the life of them.

ChevyMan2015 Enthusiast

ChevyMan2015

Posted
Posted

Does the owner's manual tell you when the change the brakes? Does it tell you when to wash the truck? Does it tell you when your tires are going to wear out? Does it tell you when your transmission is going to fail?

 

It's common knowledge. Run anything with an in-tank pump low a lot and it shortens the life. GM's are known for going through fuel pumps. This is one way to extend the life of them.

 

Those things are common knowledge, yes, but I would argue that the fuel pump "issue" is not. I have owned a GMC or Chevrolet truck since 1998. I always get gas when the gas light comes on, and I have NEVER had a fuel pump issue. So, no, it is not common knowledge for me. That is why I asked about it in the first place.

trik396 Enthusiast

trik396

Posted
Posted

I think this was probably true years ago but the way fuel is returned to the sump and architecture of current fuel systems probably makes this issue moot. Not saying it's a bad idea to keep your pump immersed in fuel but I wouldn't lose sleep over it

pm26 Senior Enthusiast

pm26

Posted
Posted

Think of fuel in the tank as electric pump motor coolant - the pump motor is actually cooled by the gasoline in the tank. As your fuel level drops so that the pump motor is partially exposed, the cooling efficiency decreases. Remember the pump runs all the time while the engine is running. So keeping that little motor cool is a good idea.

Archived

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

Go to topic listing

  • Latest Articles

  • Posts

    • Matt Parker
      Clunk when putting truck into drive and reverse.

      By Matt Parker · Posted

      I have a 2000 Silverado 1500 LS, whenever I put it into reverse and also in drive it clunks, the truck also feels sluggish when driving. Any advice/ideas ?
    • richard wysong
      Needing this part.

      By richard wysong · Posted

      Looks like it's riveted to me. What is wrong with that 1? Welcome to the Forum!
    • Grumpy Bear
      Some Assembly is Required

      By Grumpy Bear · Posted

      Missing pieces of the Assembly   Detergency vs Solvency   Not the same thing. Detergency is the mechanism that surrounds solid particulates preventing amalgamation. Usually accompanied by a Dispersant whose job it is to keep those encapsulated particles in Suspension. Solvency keeps things that can be dissolved in solution.    Salt is a solid that can be dissolved. Pepper is a solid that cannot be dissolved. A detergent/dispersant is effective on pepper but a solvent is more effective on salt. As long as the solids remain in either state, dissolved or dispersed then they can be be removed with the oil upon change.    How many wranglers does it take to herd cats? Depends on how many cats your herding. How much sponge does it take to soak up water? How much water is there to soak up? Point is most oil blends start with some herding ability and next to zero sponge and recently even fewer wranglers are being sent to do the same job.    So you start with a dozen cowboys and zero cows but at the drive progresses you pick up cows along the way, but not cowboys. At some point you have more cows that the wranglers can handle and some leave the herd. Deposits. And the API has an acceptable number of cows they are willing to let loose. In the ideal world zero is the right number for he rancher but to the butcher....a few lost is fine. This cow is beat to death. Let's move on....   Solvency isn't something oils on the Walmart shelf care about AT ALL. Problem is, you motor does. Fuels driven varnish sticks rings and only a solvent can keep them in check. The bet is that the solids driven portion that plug the expander rings and the oil drain backs and VVT screens and AFM screens will be an issue long before varnish is. Not that it wont be but if they market well enough the consumer can be kept ignorant enough to either believe it is "normal" (A quart in 1 or 2K is normal) OR is kept at bay longer than the first owner is likely to hang on to the unit. Solvency cost money.    Now the OEM's have John Q. Public buffaloed into the belief that the number cows accumulated along the trail is a known and predictable CONSTANT. It isn't. Nor is the rate at which they crossed paths with them. Only the number of wrangles is constant. Or was. Each new generation of oil sees fewer and fewer of them.    So what happens when the number of cowboys is lower (lower TBN) with each seasons trail but the trial is longer (OCI) and the number of cows along that trail continues increase? (Conditions that promote deposits).    For awhile the blenders were on to something. Better bases are harder to degrade (fewer cows) but that was overtaken by a longer trail (OCI) and improved breeding (More cows) while continuing to reduce the cowboy staffing levels (TBN/Aniline #).    Marketing has been successful. We've fired most of the staff, cows breed line bunnies, the trail is ten times longer and we've convinced the boss his ranch is in better shape that it ever was.    That kids is just the cleaning side. The side few pay attention to.     
    • davester
      Needing this part.

      By davester · Posted

      hit a junkyard.
    • Z45
      PF63 Oil Filters Going Away?

      By Z45 · Posted

      Mann+Hummel since 1941 per their web site 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...