'01 Burban high oil PSI and crappy MPG's ??

[bayareadude84]

Riddle me this ???


2001 burban 200K miles
NO CEL or pending codes !!

10W30 oil
Oil flush
Fresh rear diff fluid
New oil adapter gasket
pick up tube seal
oil pan gasket
Fram XG filter
new cold air intake
new fuel filter
New PCV
new 41-962 delco plugs and wires

my oil psi is around 45-50 idle and 60 when driving

Issue is acceleration and my MPG's are HORRIFIC !! 10-12 MPG's ?? My other now sold 01 burban with 350K miles got WAY better MPG's

Only things I haven't done is alignment and check for clogged CAT's

 

[Fless]

Post up your short- and long-term fuel trims, both banks.

What's the differential gearing?

 

[bayareadude84]

Post up your short- and long-term fuel trims, both banks.

What's the differential gearing?

3:73 with G80

I forgot to mention fuel pump IS making a loud whining noise(I suspect it's about to crap out) keeping at least 1/4 tank full and marvel mystery oil to keep it lubricated !! FP is next on my list when my mechanic gets back from vacation

 

[MassHoe04]

Do we know for sure the oil pressure gauge is displaying correct information?

Can you check with a Tech 2 scan tool or put an oil pressure tester gauge on there to verify you actually have abnormally high pressure?

On fuel economy issue, you mention in your signature that you have a $60 Amazon cold air intake.
Maybe that is throwing off the MAF sensor, which might call for more fuel than it should.
It could just be screwing up what the computer is being told for the amount of air coming in.
If it thinks too much is coming in, it will push more fuel.

You could try going back to stock air intake and filter box for a while. See if milage returns to normal...

 

[afpj]

40 psi idle and 60 psi at highway speed oil pressure is normal for his year.

 

[bayareadude84]

Do we know for sure the oil pressure gauge is displaying correct information?

Can you check with a Tech 2 scan tool or put an oil pressure tester gauge on there to verify you actually have abnormally high pressure?

On fuel economy issue, you mention in your signature that you have a $60 Amazon cold air intake.
Maybe that is throwing off the MAF sensor, which might call for more fuel than it should.
It could just be screwing up what the computer is being told for the amount of air coming in.
If it thinks too much is coming in, it will push more fuel.

You could try going back to stock air intake and filter box for a while. See if milage returns to normal...

Tech 2 and oil pressure gauge 100% not an option

I seriously doubt my budget Amazon CAI has anything to do with it. My brother has same one on his 04 hoe and I had one on my other 01 Suburban and NO MPG issues like mine has

MAF sensor would throw a code or CES but I dont have ANY codes or CEL !!

Fuel pump and A/C compressor are failing and need replace

Dave

 

[afpj]

As Fless noted, check and post up your fuel trims. Maf can start failing without throwing code. Same with map sensor. Consensus is that mafs tend to start failing at 140k. Mine was causing a rough idle at about 210k, no codes…ymmv.

 

[swathdiver]

Riddle me this ???


2001 burban 200K miles
NO CEL or pending codes !!

10W30 oil
Oil flush
Fresh rear diff fluid
New oil adapter gasket
pick up tube seal
oil pan gasket
Fram XG filter
new cold air intake
new fuel filter
New PCV
new 41-962 delco plugs and wires

my oil psi is around 45-50 idle and 60 when driving

Issue is acceleration and my MPG's are HORRIFIC !! 10-12 MPG's ?? My other now sold 01 burban with 350K miles got WAY better MPG's

Only things I haven't done is alignment and check for clogged CAT's

Oil pressure is a little higher because of the weight you are using. The motor was designed to run 5W30.

Need to hook up a manual fuel pressure gauge with a line so you can run it up to the windshield and monitor the pressure on test drives.

 

[bayareadude84]

Oil pressure is a little higher because of the weight you are using. The motor was designed to run 5W30.

Need to hook up a manual fuel pressure gauge with a line so you can run it up to the windshield and monitor the pressure on test drives.

Yes 5W-30 when it was NEW !! No it's got 200K miles !! Was told by many folks 10W30 wont make much of a difference??? But winter is coming and moving to Chicago area soon so I'm changing oil filter again and use Shell rotella gas/truck I have in my oil stash

Manual Fuel pressure not option at moment

Dave

 

[bayareadude84]

As Fless noted, check and post up your fuel trims. Maf can start failing without throwing code. Same with map sensor. Consensus is that mafs tend to start failing at 140k. Mine was causing a rough idle at about 210k, no codes…ymmv.

I hooked up my scanner Bank 1 and 2 Long fuel trims did not match were off a bit. But short trims were the same ???

I'll order new MAF/MAP sensor on Amazon today


Dave