5.3 litre with oil pressure problems

[vettedreamer]

Folks have another mechanical type question. My 07 sierra 5.3l new body stye 1500 has no oil pressure on start up, once the rpms are raised oil pressure come up to normal and good to go though you sure can here the valves chattering till it settles out in about 15 seconds. Took her to the local mech to change my oil pump (total assumption on my part) they got the wrong one in so the mechanic did some investigating and thought it was the sending unit but alas just called and said no go. "Your only option is a new engine" X*&(X)%$ that I said put her together I'll come pick her up and run her till she drops.

Any thoughts or suggestions

[Dr. Phil A]

Are you doing your own oil changes? Make sure you are getting the right filter with the backflow valve in it. really all it is is a flap of rubber but it keeps the oil pressure on after shut down.

I have a 5.3 that has been regularly maintained and when I do an oil change I add a litre of Lucas Heavy Oil Stabilizer. This improved my oil pressure 20 psi. Do this with every oil change. The Lucas sticks in a very thin coating in between surfaces and reduces friction on start up.

[pikergolf]

Are we talking about gas or diesel? reason I ask I have a caravan on it's last legs and the lifters rattle till the thing warms up. Just wondering about the oil treatment.

[tonka]

well i have a 5.7 chevy with 340k on it and she get rotella 15-40, makes about 0 oil pressure all the time, and has gone 20k on the rotella and counting. Filler her up and go

[RumRugby]

Are we talking about gas or diesel? reason I ask I have a caravan on it's last legs and the lifters rattle till the thing warms up. Just wondering about the oil treatment.

Chevy 5.3L is a gas, the 6.6L is the diesel.

Did they try more then one oil pressure sensor (sending unit)? I've seen some aftermarket ones be total junk right out of the box, Standard Motor Products oil pressure sensor/sending unit/switch.

That Lucas oil stabilizer is fantastic! I used the Lucas trans fix in my truck that had long/hard shifting, 10km it was back to normal. My brother in law put the oil stabilizer in his 1991 Eagle Talon every oil change, after 300k km when they took the engine apart the cross hatch pattern from factory was still visible in the cylinders.

How many km are on it? Seems strange that an 07 truck would have a blown engine. . .unless the regular maintenance wasn't done.

[great white whaler]

Go to a mechanical oil pressure gauge.

[bearbuster]

Are you low on oil??

[berjerkin]

Lucas

[super7mag]

Go to a mechanical oil pressure gauge.

x2, electric is just a guessing game. I'm not a huge fan of the 5.3's, but had abuddy litterly run the livin pi$$ out of a 5.7, you couldn't kill it. If you have no payments runner till it drops, just keep an eye out for a replacment in the mean time.

[Dr. Phil A]

my 99 5.3 has 445,000 km on it and going strong. Love the truck. It does help that in a former life I was a GM tech. Still like tinkering.

Did the shop you were at put a master gauge on it? That would give you a better idea what you are really getting for pressure.

After doing some reading on the Chev/GMC the information said not to change oil until the Oil Change lite came on. With Lucas added to the oil I was close to 15000 km on an oil change. The oil was still lighter than normal.

[deanmc]

Taken from another forum.
http://gmcowners.com/gmc-forum/showthread.php?t=16468

Here is a TSB concerning low oil pressure from 2007 to 2010 GM Vortec family engines.

PIP4158C: Low Oil Pressure Due To Seized Oil Pressure Relief Valve - (Dec 29, 2009)


Subject: Low Oil Pump Pressure due to Seized Oil Pressure Relief Valve

Models: 2008-2009 Buick Lacrosse, Allure (Canada Only)
2007-2010 Cadillac CTS-V, Escalade
2007-2010 Chevrolet Avalanche, Corvette, Silverado, Suburban, Tahoe
2007-2008 Chevrolet Monte Carlo SS
2007-2009 Chevrolet Impala SS, Trail Blazer
2009-2010 Chevrolet Colorado
2010 Chevrolet Camaro2007-2010 GMC Envoy, Sierra, Yukon
2009-2010 GMC Canyon
2008-2010 Hummer H2
2008-2010 H3 Alpha
2008 Pontiac Grand Prix GXP
2008-2010 Pontiac G8 GT
2007-2009 Saab 97x
with the Following Aluminum V8 Engine RPOs:
L76, L77, L92, L94, L99, L9H, LC9, LH6, LH8, LH9, LS2, LS3, LS4, LS7, LS9, LSA, LZ1

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:

Some customers may complain of low oil pressure, no oil pressure, and/or engine noise, which may be the result of a sticking oil pump pressure relief valve. In some instances, this may occur intermittently if the valve frees up when the engine cools down.
Recommendation/Instructions:

If SI diagnosis isolates low mechanical oil pressure at the oil filter housing and oil pressure sensor, replace the oil pump, flush the oil cooler lines (if equipped), clean the inside of the oil pan, change the oil and filter, and re-evaluate the concern.

Notice: If an engine noise is noticed after replacing the oil pump, follow the SI diagnosis and repair the engine as necessary.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

[vettedreamer]

ya she's a gas job. The put a gauge on it if I remember correctly she was 0 psi to start normal at 2200 rmp and 20psi at idle.

[eastcoast]

put in some lucas and make sure you use synthetic, may buy you more time with it if it's is a bad pump on start up.

[vettedreamer]

since day one she's had synthetic every 5 k hard oil field miles and sitting at 399765km as we speak.

This will be the first time since 07 this girl as left me on the highway and its going to be expected bahahahahahah

Lucus here I come

[Flyfisher87]

I had a 5.3L once. Never again. It was in an 05 Sierra Z71. 90 000k on it and found out in January it had a cracked head. One GM tech told me these engines are notorious for that.

[AbProwler]

99 5.3 in a 1500 Off Road, 508.000, just started rattling on start up!

[vettedreamer]

ya these 5.3 seem notorious for allot of interesting problems. blocks oil bypasses, stretched valves but in all honesty 400,000 4 stretched valves and now this I'm pretty happy. Interesting note I can find 6.0 litres drop in replacements all over the place for $2500 this 5.3 not only seems hard to find but more expensive as well.
The truck on the other hand one set of wheel bearings a month ago we ground off the factory ball joints, transmission and transfer case strong, its a gfx model so she's loaded other than gravel destroying rear wiring every two years what a great vehicle.

[cody c]

if you hear it clacking at start up a mechanical gauge wont fix it just confirm what you already now. The 5.3 isnt a bad little motor as youve seen by now. Have them look at the pressure relief valve or start looking on kijiji for a good used one.

[vettedreamer]

From what I understand the prv is on the side of the oil pump, so if she's apart may as well change the pump but 1200 bucks for that and with some luck I should be able to find a drop in for about 2k . So in the end she's a wash.

and yep thought it was a decient engine though a little underpowered.

[deanmc]

ya these 5.3 seem notorious for allot of interesting problems. blocks oil bypasses, stretched valves but in all honesty 400,000 4 stretched valves and now this I'm pretty happy. Interesting note I can find 6.0 litres drop in replacements all over the place for $2500 this 5.3 not only seems hard to find but more expensive as well.
The truck on the other hand one set of wheel bearings a month ago we ground off the factory ball joints, transmission and transfer case strong, its a gfx model so she's loaded other than gravel destroying rear wiring every two years what a great vehicle.

Realize that you will pay more in gas than you will for a 5.3. My 6.0 gets 15 mpg if you really baby it. Terrible engine on fuel.

[lugeboy]

A 5.3 has Hyperutectic pistons which is they are not round when cold and will rattle it is completly normal. I would hook up a mechanical guage to confirm things are good and just keep running it.

[vettedreamer]

A 5.3 has Hyperutectic pistons which is they are not round when cold and will rattle it is completly normal. I would hook up a mechanical guage to confirm things are good and just keep running it.


Lugeboy....... six pack I drive ........your gauge .......were on ..........I still think its a simple fix the mechanic isn't seeing.

btw honey helped a very very little bit on start up it seems to stop rattling a little sooner. still no pressure without rpm's. Second treatment in 7 days with oil change.