Intermittent low oil pressure...
January 26th, 2015, 6:46 PM
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Intermittent low oil pressure...
Recently purchased a 2009 suburban Z71. Love the thing, until now. It will be running just fine when it will start to stutter. The oil pressure goes all the way down, and eventually the car dies. You go to restart it, and the starter takes off on it's own. It'll continue to run bad, but the pressure is fine. Eventually it goes back to normal within a few moments. There seems to be no pattern of when it happens. Any ideas? Thanks.
January 27th, 2015, 11:11 AM
#2
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The oil pressure is dropping because your rpm's are dropping. Do a fuel pressure check to see if it is a weak fuel pump. Do it when it is acting up if you can. Change the fuel filter now.
March 20th, 2015, 10:00 PM
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Ok, so my understanding is my fuel filter is in my fuel pump. I'm not going to dig that out for something that happens once in awhile. Not totally convinced it's fuel related anyways. What about ECM? Or dirty MAF?
March 22nd, 2015, 8:07 AM
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The ECM or MAF are more likely to set a fault code, where as poor fuel pressure will not.... You can clean the MAF but checking the fuel pressure with engine running and key on ignition off is a no brainer place to start, its easy and eliminates a multitude of possibilities.. saying you don't want to go there won't not make it the issue....
April 26th, 2015, 4:14 PM
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Ok. So finally got to checking the fuel pressure. Hoping I did it right. When I turned on the ignition key, the pressure only came up to about 24 psi. Started with no problem and jumped to 58 psi. After about 10 seconds of idle, it dropped back to about 44 psi. Took it for a spin with the gauge propped on the windshield. The guage stayed at 44 psi unless the rpm got above 5000, at which time it would climb and then drop as soon as it shifted. When I turn the engine off, the psi climbs to about 50 with minimal pressure loss. Now if I turn the ignition on while it is still at 50 psi, it will jump to about 58.
April 26th, 2015, 4:27 PM
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With the exception of the 24 psi reading those are okay numbers, above 55psi would better but I don't think I'd replacing the fuel pump just yet...
When it stutters is it while driving or while at a stop?
if only at stop that could be something like a Idle Air Control valve....
I'd suggest some basics to start with...
Clean the throttle body https://chevroletforum.com/forum/tah...-gmt900-54328/
Inspect clean check spark plugs or replace
Clean the MAF
Check / replace the air filter
Consider adding a couple of bottles of Techron or BG fuel injector cleaner..
Check for codes... verify that your check engine light is working, it should come on momentarily when you first turn the key on but no crank... I say this because its possible to have a code but not know it because the light is out...
The above are easy *free things to try before digging deeper and throwing parts at it just yet....
When it stutters is it while driving or while at a stop?
if only at stop that could be something like a Idle Air Control valve....
I'd suggest some basics to start with...
Clean the throttle body https://chevroletforum.com/forum/tah...-gmt900-54328/
Inspect clean check spark plugs or replace
Clean the MAF
Check / replace the air filter
Consider adding a couple of bottles of Techron or BG fuel injector cleaner..
Check for codes... verify that your check engine light is working, it should come on momentarily when you first turn the key on but no crank... I say this because its possible to have a code but not know it because the light is out...
The above are easy *free things to try before digging deeper and throwing parts at it just yet....
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April 26th, 2015, 5:49 PM
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I cleaned the TB and maf a few weeks ago. The TB was filthy. Found out the cel worked when I forgot to plug in the maf.
Replaced all the spark plugs with ac delco iridiums. Car was running great, but died on my wife again the other day.
Here's a far fetched thought. The car had a hard time with the 2-1 shift. Is there a possibility it's pulling the Rpms too low?
Replaced all the spark plugs with ac delco iridiums. Car was running great, but died on my wife again the other day.
Here's a far fetched thought. The car had a hard time with the 2-1 shift. Is there a possibility it's pulling the Rpms too low?
April 27th, 2015, 9:56 AM
#9
Administrator
I cleaned the TB and maf a few weeks ago. The TB was filthy. Found out the cel worked when I forgot to plug in the maf.
Replaced all the spark plugs with ac delco iridiums. Car was running great, but died on my wife again the other day.
Here's a far fetched thought. The car had a hard time with the 2-1 shift. Is there a possibility it's pulling the Rpms too low?
Replaced all the spark plugs with ac delco iridiums. Car was running great, but died on my wife again the other day.
Here's a far fetched thought. The car had a hard time with the 2-1 shift. Is there a possibility it's pulling the Rpms too low?
April 28th, 2015, 9:25 AM
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Well it did it to my wife yesterday. She said it started bucking while she was cruising, so there goes my transmission idea.
I'll try to look for some vacuum leaks.
My big confusion is how intermittent it is. The car will run like a top for weeks and then have an episode, and there's no consistency to when it happens.
I'll try to look for some vacuum leaks.
My big confusion is how intermittent it is. The car will run like a top for weeks and then have an episode, and there's no consistency to when it happens.