#5.3 rocker arm torque free

Q I have a 1997 Jeep Grand Cherokee with a V8 engine and 160,000 miles. I'd suggest making sure that all 12 rocker bolts are properly tightened to the updated specs. This could progressively remove the clearance between valve/rocker/pushrod/valve lifter, causing a mechanical binding action that might work the rocker bolt loose.ДЄt this point, the problem has been repaired for the rocker arms that came loose. The two possible causes for this would be a significant carbon buildup on the face of the valve or top of the piston, causing physical contact between the two, or wear, erosion and/or excess heat causing the valve seat to sink into the cylinder head. The only other possible explanation I can think of is some type of mechanical interference. The most likely cause for the loose rocker arm bolts in your engine is either inadequate tightening originally, or an effort to adjust the rocker arms at some point in the engine's life. The valve lifters are hydraulic, so no adjustment beyond this tightening specification is necessary. The bolts should be tightened with a torque wrench to 124 inch-pounds, then tightened an additional 30 degrees of clockwise rotation. My Alldata automotive database pulled up GM service bulletin 02-06-01-034 updating the tightening specifications for the rocker-arm bolts.

#5.3 rocker arm torque free

From your description, it sounds as if the bolts worked loose over time until several of them backed all the way out, causing the rocker arms to pop free of the pushrod and valve stem. Why would this happen? This is the second time that this has happened to this vehicle, but not to the same rocker arm as the first time.ДЄ The rocker arms that actuate the valves in this engine pivot on a special bolt that is threaded into the cylinder head. The mechanic was able to get them back in, and the car is running fine now. I took the vehicle to a shop, which told me I had two rocker arms blown right out of the head, and two more were working their way loose. This weekend I got a flashing check-engine light with a severe misfire. *Horsepower and torque ranges account for the difference between gasoline and E85 fuel.Q I own a '99 Chevy Lumina with a 3.1-liter V6. ( Summit RacingвЂ™sВ Brian Nutter and Paul Spurlock contributed to this article.) Chevy L83 & L8B Engine Specs L83/L8B Performance Specifications Engine Ratings The information listed here is for a stock engine. Other than the alternator, both engines use the same major components. The BAS3 recharges the battery AND is used to restart the gas engine after it shuts down. The engine uses a BAS3 (Belt Alternator Starter) in place of an alternator. The L8B also uses stop/start technology that will shut down the engine at traffic lights and during slow, stop-and-go traffic. The notable difference between the L83 and L8B engines is that the L8B includes GMвЂ™s eAssist powertrain, which combines the traditional gas-powered engine with an electric motor. The engines also use direct fuel injection technology, which shoots fuel directly into the combustion chamber instead of the intake runner. They are all-aluminum small blocks, both of which incorporate Active Fuel Management (AFM), Variable Valve Timing (VVT), and are flex-fuel capable (E85). These LT-based engines are commonly referred to as EcoTec3 5.3L engines. This is an engine specification guide for General MotorsвЂ™ fifth-generation L83 and L8B engines that launched in 2014.