Anybody have Issues with their 5.3's?
- Thread starter AlwaysVTEC
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Bad00SS
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there is some bulliten like that for ls1/ls6 motors also. 1qt every 1k miles is a bit excessive, but they gotta cover there ass. 1qt every 3k miles is more like what most of the ls1's with problems will use. shitty quality control makes some worse than others. on my personal car with an ls1 it was the pcv system that wasnt working properly. now i have an oil catch can so it doesnt go back into my intake manifold.
The 5.3 truck motor is apart of the vortec line of motors. The blocks are pretty close to the LSX motors by design but are are not the same. The SS/GXP motors are a LS motor. Basically a destroked and debored out LS1.
Smokinhot
3-man rules!!!!
not really... the LS4 in the W bodies and the LM7 or L59 in the trucks are nearly identical... the only differences are that the LS4 has no provision for a block mounted starter, and the displacement on demand system... other than the intake manifold and the accesories and engine mount locations, you would be hard pressed to tell the blocks apart
Generation IV 5.3L LS4 V8 Overview
The 5.3L LS4 shares the basic architecture of the 6.0L LS2. This includes an all aluminum block, six-bolt main bearing caps, deep-skirt cylinders, and a structural oil pan. It has the 243 casting LS6 heads with LS1 valve springs, which are good for 6200-6300 rpms.
Engineers had to mount this engine sideways so some changes were made. The crankshaft is shorten by 13 mm overall, 3 mm at the flywheel and 10 mm at the accessory drive. This was done to accommodate a more compact accessory drive. Instead of a 2 belt system there is only 1 long serpentine belt, even with this to save space there is only about 2 inches between the crankshaft pulley and the passenger side wheel well. The water pump is mounted off center with elongated passages to connect to the block (see picture). Also a rear facing intake manifold was designed. To ensure proper oiling during high-g cornering the oil pan has special baffles built in. Since Displacement on Demand uses oil for activation an oil pump with 31% more flow than previous LS2 type oil pumps is used.
Displacement: 325ci (5328cc)
Compression Ratio: 10:1 (premium fuel is recommended)
Bore x Stroke: 3.78" x 3.622" (96mm x 92mm)
Firing Order: 1-8-7-2-6-5-4-3
Horsepower: 303 hp @ 5600 rpm
Torque: 323 lb-ft @ 4400 rpm
Fuel Cut-off: 6100 rpm
5.3L LS4 V8
GM Dyno
Displacement on Demand (DoD) General Information
The original name was Displacement on Demand (DoD). For the start of the 2006 model year GM renamed it Active Fuel Management (AFM).
During light load conditions while in 3rd or 4th gear the ECM will shut down cylinders 1, 4, 6, and 7 to put the engine in V4 mode. The engine will not enter V4 mode while cranking, idleing, or heavy acceleration. To shut down the cylinders the intake and exhaust valves stay closed and the fuel injectors stop feeding gas. The ECM times the shutdown so that each deactivated cylinder keeps the exhaust charge from the previous combustion cycle. This pressure on the pistons keeps them from rocking around in the cylinder causing vibration and oil consumption. Complete cylinder deactivation is accomplished in about 250 milliseconds.
The engine components involved in cylinder deactivation are the valve lifter oil manifold (VLOM) and special valve lifters. The VLOM consists of 4 solenoids that control oil flow to 8 valve lifters. Each solenoid goes with a certain cylinder and its 2 valve lifters.
When DoD is commanded on by the ECM the 4 solenoids energize and allow oil to flow to the valve lifters. The special valve lifters are made of an inner lifter and outer lifter with a spring loaded locking pin holding them together. When the oil gets to the lifters the pin is pushed out of place and the inner and outer part of the lifter are allowed to move seperately. The camshaft is still pushing on the outer part of the lifter, but the inner part of the lifter is no longer pushing up on the pushrod. This keeps the intake and exhaust valve shut permanently until the ECM commands DoD off. At this point the solenoids stop oil flow to the lifters and the spring loaded lifter pins lock back into place, causing the lifters to return to normal operation.
The valve lifter oil manifold assembly (1) is bolted to the top of the engine block beneath the intake manifold assembly. The oil manifold consists of four electrically operated and normally-closed solenoids (2). Each solenoid directs the flow of pressurized engine oil to the DoD intake and exhaust valve lifters (5). The oil pressure relief valve (6), located in the left rear area of the oil pan, regulates engine oil pressure to the lubrication system and the oil manifold.
When enabling conditions are met for DoD operation, the PCM will ground each solenoid control circuit in firing order sequence, allowing current to flow through the solenoid windings. With the windings energized, the solenoid valves open and direct pressurized engine oil through the manifold into eight vertical passages in the engine block lifter valley. The eight vertical passages, two per cylinder, direct pressurized oil to the valve lifter bores of the cylinders to be deactivated. When vehicle operating conditions require a return to V8 mode, the PCM will turn OFF the ground circuit for the solenoids, allowing the solenoid valves to close. When the solenoid valves are closed, remaining oil pressure is exhausted through the bleed passages of the manifold into the engine block lifter valley. The housing of the oil manifold incorporates several oil bleed passages that continually purge trapped air from the manifold and engine block.
To help control contamination within the DoD hydraulic system, a small replaceable oil filter (4) is located in the manifold oil inlet passage. The oil pressure sensor (3) monitors engine oil pressure and provides information to the PCM.
When operating in V8 mode, the DoD valve lifters function similar to the non-DoD valve lifters. The DoD oil manifold solenoids are in the closed position with no pressurized oil directed to the valve lifters. The pushrod (1) travels upward and downward to actuate the rocker arm and valve. The spring loaded locking pins (5) of the lifter are extended outward and mechanically lock the pin housing (4) to the outer body of the valve lifter (3).
When the DoD system is commanded ON, the PCM will direct the solenoids of the oil manifold to open and direct pressurized oil to the valve lifters. Oil travels through the manifold and engine block oil galleries and enters the inlet port (6) of the valve lifter.
When operating in V4 mode, pressurized oil forces the locking pins (11) inward. The pushrod (7) remains in a constant position and does not travel upward and downward. The outer body of the lifter (9) moves upward and downward independently from the pin housing (10). The valve lifter spring (8) retains tension on the valve train components to eliminate valve train noise.
When the DoD system is commanded OFF, the PCM directs the solenoids of the oil manifold to close, stopping the flow of pressurized oil to the valve lifters. The oil pressure within the lifter will decrease and the locking pins will move outward to mechanically lock the pin housing and outer body.
The 5.3L LS4 shares the basic architecture of the 6.0L LS2. This includes an all aluminum block, six-bolt main bearing caps, deep-skirt cylinders, and a structural oil pan. It has the 243 casting LS6 heads with LS1 valve springs, which are good for 6200-6300 rpms.
Engineers had to mount this engine sideways so some changes were made. The crankshaft is shorten by 13 mm overall, 3 mm at the flywheel and 10 mm at the accessory drive. This was done to accommodate a more compact accessory drive. Instead of a 2 belt system there is only 1 long serpentine belt, even with this to save space there is only about 2 inches between the crankshaft pulley and the passenger side wheel well. The water pump is mounted off center with elongated passages to connect to the block (see picture). Also a rear facing intake manifold was designed. To ensure proper oiling during high-g cornering the oil pan has special baffles built in. Since Displacement on Demand uses oil for activation an oil pump with 31% more flow than previous LS2 type oil pumps is used.
Displacement: 325ci (5328cc)
Compression Ratio: 10:1 (premium fuel is recommended)
Bore x Stroke: 3.78" x 3.622" (96mm x 92mm)
Firing Order: 1-8-7-2-6-5-4-3
Horsepower: 303 hp @ 5600 rpm
Torque: 323 lb-ft @ 4400 rpm
Fuel Cut-off: 6100 rpm
5.3L LS4 V8
GM Dyno
Displacement on Demand (DoD) General Information
The original name was Displacement on Demand (DoD). For the start of the 2006 model year GM renamed it Active Fuel Management (AFM).
During light load conditions while in 3rd or 4th gear the ECM will shut down cylinders 1, 4, 6, and 7 to put the engine in V4 mode. The engine will not enter V4 mode while cranking, idleing, or heavy acceleration. To shut down the cylinders the intake and exhaust valves stay closed and the fuel injectors stop feeding gas. The ECM times the shutdown so that each deactivated cylinder keeps the exhaust charge from the previous combustion cycle. This pressure on the pistons keeps them from rocking around in the cylinder causing vibration and oil consumption. Complete cylinder deactivation is accomplished in about 250 milliseconds.
The engine components involved in cylinder deactivation are the valve lifter oil manifold (VLOM) and special valve lifters. The VLOM consists of 4 solenoids that control oil flow to 8 valve lifters. Each solenoid goes with a certain cylinder and its 2 valve lifters.
When DoD is commanded on by the ECM the 4 solenoids energize and allow oil to flow to the valve lifters. The special valve lifters are made of an inner lifter and outer lifter with a spring loaded locking pin holding them together. When the oil gets to the lifters the pin is pushed out of place and the inner and outer part of the lifter are allowed to move seperately. The camshaft is still pushing on the outer part of the lifter, but the inner part of the lifter is no longer pushing up on the pushrod. This keeps the intake and exhaust valve shut permanently until the ECM commands DoD off. At this point the solenoids stop oil flow to the lifters and the spring loaded lifter pins lock back into place, causing the lifters to return to normal operation.
The valve lifter oil manifold assembly (1) is bolted to the top of the engine block beneath the intake manifold assembly. The oil manifold consists of four electrically operated and normally-closed solenoids (2). Each solenoid directs the flow of pressurized engine oil to the DoD intake and exhaust valve lifters (5). The oil pressure relief valve (6), located in the left rear area of the oil pan, regulates engine oil pressure to the lubrication system and the oil manifold.
When enabling conditions are met for DoD operation, the PCM will ground each solenoid control circuit in firing order sequence, allowing current to flow through the solenoid windings. With the windings energized, the solenoid valves open and direct pressurized engine oil through the manifold into eight vertical passages in the engine block lifter valley. The eight vertical passages, two per cylinder, direct pressurized oil to the valve lifter bores of the cylinders to be deactivated. When vehicle operating conditions require a return to V8 mode, the PCM will turn OFF the ground circuit for the solenoids, allowing the solenoid valves to close. When the solenoid valves are closed, remaining oil pressure is exhausted through the bleed passages of the manifold into the engine block lifter valley. The housing of the oil manifold incorporates several oil bleed passages that continually purge trapped air from the manifold and engine block.
To help control contamination within the DoD hydraulic system, a small replaceable oil filter (4) is located in the manifold oil inlet passage. The oil pressure sensor (3) monitors engine oil pressure and provides information to the PCM.
When operating in V8 mode, the DoD valve lifters function similar to the non-DoD valve lifters. The DoD oil manifold solenoids are in the closed position with no pressurized oil directed to the valve lifters. The pushrod (1) travels upward and downward to actuate the rocker arm and valve. The spring loaded locking pins (5) of the lifter are extended outward and mechanically lock the pin housing (4) to the outer body of the valve lifter (3).
When the DoD system is commanded ON, the PCM will direct the solenoids of the oil manifold to open and direct pressurized oil to the valve lifters. Oil travels through the manifold and engine block oil galleries and enters the inlet port (6) of the valve lifter.
When operating in V4 mode, pressurized oil forces the locking pins (11) inward. The pushrod (7) remains in a constant position and does not travel upward and downward. The outer body of the lifter (9) moves upward and downward independently from the pin housing (10). The valve lifter spring (8) retains tension on the valve train components to eliminate valve train noise.
When the DoD system is commanded OFF, the PCM directs the solenoids of the oil manifold to close, stopping the flow of pressurized oil to the valve lifters. The oil pressure within the lifter will decrease and the locking pins will move outward to mechanically lock the pin housing and outer body.
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we arent sure of anything yet, but when the motor collapses the lifters and seals off the combustion chambers on the DOD cylinders, the oil that normally lubricates the cylinder walls is supposedly being consumed/ not drained back properly because of lack of combustion pressure forcing it back past the rings. then in turn, when those cylinders fire back up the oil is burned off...... that is the theory going around thus far, who knows if its correct or not
ive worked on a couple of ls4's with oil usage problems. there are a couple bulletins out, one is for the valves being nicked from the factory, and chewing up the valve stem seal (which gm had me replace both complete cylinder heads), and the other is a pcv passage issue. the pcv runs through the valve covers, and they get crud in them and cause excessive oil usage.
i have seen a couple cases of rings causing the issue too, but it was a clear cut case of the plugs oil fouled, and the cc's totally gummed up. the DOD/AFM wont make any different in oil usage, all you're doing is just moving oil pressure around....
fwiw, gm says 1 qt every 2000 miles is normal. personally i would be pissed to see my 25k car uses that much oil, but it really does vary with driving habits
side note, the ls4 is 10:1 cr, and the T motor is like 9.2:1 iicr.....
the blocks are similar, and the intake is similar, but other than that, they are NOT alike.
i have seen a couple cases of rings causing the issue too, but it was a clear cut case of the plugs oil fouled, and the cc's totally gummed up. the DOD/AFM wont make any different in oil usage, all you're doing is just moving oil pressure around....
fwiw, gm says 1 qt every 2000 miles is normal. personally i would be pissed to see my 25k car uses that much oil, but it really does vary with driving habits
side note, the ls4 is 10:1 cr, and the T motor is like 9.2:1 iicr.....
the blocks are similar, and the intake is similar, but other than that, they are NOT alike.
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