Q: What are the steps and precautions involved in replacing the Timing Chain and Variable Timing Sprocket in V8 engine on Cadillac Escalade?
A: The use of timing system is quite delicate and if an error is made on the same, there will be severe damages to the engine, thus, it is advisable that, only professionals try this process and in case there is any doubt, one should consult an expert. Start with the removal of the first end terminal of the battery then empty the cooling system and the engine oil. For 5.3L and 6.2L models, the oil pan, vacuum pump and coolant manifold need to be removed while on the other hand the AC compressor needs to be held in place while the lines do not need to be disconnected. On 6.0L models, some of the crops include; If equipped, disconnect the wiring from the camshaft position sensor and actuator magnet, remove the water pump, and take off the crankshaft balancer. The timing chain cover mounting bolts must be removed, care being taken not to mar the cover, and the oil pump must be detached. Force the timing chain tensioner towards the chain until a special tool or a 3 mm drill bit can be inserted, then turn the crankshaft until you have the timing marks lined up at twelve and six but do not or turn the camshaft or crankshaft until the chain is back into its position. After that, eliminate the solenoid valve that was attached to the upper sprocket assembly, and dispose of it Later, unbolt, the actuator from the camshaft and exhaust the actuator assembly with the chain as well. Check the wear condition and conditions of timing chain tensioner, camshaft and crankshaft sprockets and in case where the crankshaft sprocket has to be removed from the crank shaft do it gently. Timing chains should be replaced at one time with the camshaft and crankshaft sprockets; gasket material should be cleaned off the cover and engine block. Check the position of the crankshaft sprocket in regard to the Woodruff key and place it on the crankshaft but do not hammer it. New chain place the new chain over the camshaft sprocket and make sure that the chain marks are lined correctly and no part of the chain is out of the engine block. Check the new camshaft position actuator valve snugly and compress the timing chain tensioner then install it and rotate the crank shaft manually to as much as possible for resistance. Bolt on the oil pump, perform cleaning of sealing surfaces, apply RTV on sealing surfaces, tighten this loosely with gasket and use a cover aligner tool to rightly align the timing chain cover. Last, fit a new crankshaft oil seal, and follow the reverse procedure to that of the removal part for the rest of the fitting process; refill the cooling and engine oil, replace the engine oil filter, and look for leaks after the vehicle has been run for some time.