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Oil Pressure 2005 Z-71


weo38
12-28-2009, 06:35 AM
What oil pressure is normal for my 05 Z-71? I have 84,000 miles on the truck and use synthetic oil. At an idle at operating temp I see about 25 -30 psi. At high way speed about 40 psi. When I give some gas to pass or speed up on an on ramp I get about 45 psi. I know it doesn't sound low but just want to see what others are getting so I can stop these evil oil pump thoughts going through my head:screwy:.

j cAT
12-28-2009, 08:52 AM
What oil pressure is normal for my 05 Z-71? I have 84,000 miles on the truck and use synthetic oil. At an idle at operating temp I see about 25 -30 psi. At high way speed about 40 psi. When I give some gas to pass or speed up on an on ramp I get about 45 psi. I know it doesn't sound low but just want to see what others are getting so I can stop these evil oil pump thoughts going through my head:screwy:.

those pressures are lower than my engine..43psi-65 psi are what I get..this is from cold start to idle when hot..with synthetic I noticed much lower pressures when cold..used to go up to 75-80 psi with dino oil..as long as it is above 20psi you should be good...

It may mean that the oil pump is going or the main bearings are worn..or the oil pressure sender is off/check with a pressure guage.
also I run 5-30wt mobil 1..no fram filters allowed !

weo38
12-28-2009, 10:34 AM
I run Amsoil 5w-30. I checked my oil recently and noticed I was down over a quart and refilled it to just below the full line:shakehead. Not sure where the oil went but it was low. I am scared I hurt the pump with it being that low.

j cAT
12-28-2009, 02:15 PM
I run Amsoil 5w-30. I checked my oil recently and noticed I was down over a quart and refilled it to just below the full line:shakehead. Not sure where the oil went but it was low. I am scared I hurt the pump with it being that low.

being 2quarts down wont hurt the pump..the reason you want the oil at the correct level is for cooling..with low oil the oil supply being small cannot cool off..hot oil is what gets the engine into trouble...

lets say the rings are worn then you get hot combustion chamber gases blowing by the cylinders into the crankcase this heats up the oil then the PCV system injects it into the intake manifold to be burned off..

the crank bearings if worn also heat up the oil..how long have you used the amsoil ? I know of owners that find it a very good product..

even with a synthetic oil the filter is also the big part of engine wear..prevention..

weo38
12-29-2009, 06:43 PM
I've been using amsoil in this truck since I bought it two years ago. Used it for years in other vehicles with no problems. Could the gauge be giving faulty readings?

iroc343
12-30-2009, 07:28 AM
Unless you ran it low on oil, or the pressure reading has changed recently, I think the oil pressure you are seeing is fine and definately within service limits.

j cAT
12-30-2009, 08:45 AM
I've been using amsoil in this truck since I bought it two years ago. Used it for years in other vehicles with no problems. Could the gauge be giving faulty readings?

like I said before check pressure with a guage to be sure..



next just because your using a high rated oil don't mean anything if your using a crappy fram like filter......

another reason though not common with these vehicles is dirt/dust entering the intake....

cramer_77
12-30-2009, 05:20 PM
I got a friend that works at a GM dealership, and i have talked to him a couple of times at his work and saw a pile of valve covers laying there, so i asked him what that was about. He said that they were bad and causing the engine to burn off oil, not enough to produce smoke, but enough to make the oil level drop.

ColoradoSilverado
12-30-2009, 08:45 PM
jCat, just curious....how many miles you got on your Silverado ?

Bert

j cAT
12-30-2009, 10:05 PM
jCat, just curious....how many miles you got on your Silverado ?

Bert

I have 125,ooomi..just changed the engine oil mobil1 5-30wt , 7500mi used 1/4 qt...pressures are the same as new..

ColoradoSilverado
12-31-2009, 06:14 AM
Only reason I'm asking is because you're always saying not to use Fram oil filters, I bought my truck 5 years ago with a 104K on it, now I'm closing in at 200K. Always use Valvoline 10W35 High mileage oil and the Fram Though Guard Oil filters. Those filters work just fine for me, also use them in our Nissan Maxima which just past the 150K mark. Just my 2 cents about Fram.

Bert

j cAT
12-31-2009, 09:13 AM
Only reason I'm asking is because you're always saying not to use Fram oil filters, I bought my truck 5 years ago with a 104K on it, now I'm closing in at 200K. Always use Valvoline 10W35 High mileage oil and the Fram Though Guard Oil filters. Those filters work just fine for me, also use them in our Nissan Maxima which just past the 150K mark. Just my 2 cents about Fram.

Bert

the fram extra guard/tough guard may be better than the standard fram oil filter....If you go to the amsoil web site you will NOT see any fram oil filters listed....

reports show when these frams are cut open they lack proper fabrication..also the filter media is smaller and also not of an ability to remove small particles..

synthetic oil puts more stress on the filter material...so thats why I will go with the wix or the purolator plus filters...cutting these open they are almost exactly the same...

when I had the 1983 for 380,ooomi I used dino oil with the ac delco oil filters when they were made by ac...I changed the 10-30wt dino castrol oil every 3,ooomi...the engine used 1/2qt when I sold it 17 yrs old..

filters and changing the oil at the proper time is what will determine your engines performance ..go too long on the oil change or use cheap filters you will loose...it don't take long to do serious engine damage..

with trucks that work hard I know of contractors that have the oil tested to ensure they are changing at the correct interval.

weo38
01-04-2010, 06:21 AM
If I did hurt the engine what are my options? Could I rebuild the bottom end or is it easier to go with a reman short/long block? I would have to do the work over a weekend since the truck is my daily driver.

j cAT
01-04-2010, 08:52 AM
If I did hurt the engine what are my options? Could I rebuild the bottom end or is it easier to go with a reman short/long block? I would have to do the work over a weekend since the truck is my daily driver.

this oil pressure reading is not at a level that would require any work . the pressure needs to be checked with a guage..even the dash unit can be defective in indicating the correct pressures..

using a quart of oil in a 1,ooomi is not that bad...I would not be too concerned until you get a better handle on whats actually happening here..

weo38
01-04-2010, 12:17 PM
Is there a good way to check oil pressure? I am starting to be suspect of the gauge on the dash. I was just wondering if there is a tool or setup I can use to check it.

j cAT
01-04-2010, 03:55 PM
Is there a good way to check oil pressure? I am starting to be suspect of the gauge on the dash. I was just wondering if there is a tool or setup I can use to check it.

locate the sender unit on the engine then remove, get thread size ..get fitting to match this thread with a 3ft lenght of tubing to the pressure guage..it don't need be expensive ...any pressure guage that can go up to 100psi will do ...air compressor type...sears//homedepot etc..

then just screw it in and see if it is higher than the dash reading..

if it is indicating a higher reading then install the new sender..this may be the problem..or possibly the connector or the dash unit..

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