VW engine - timing chain problem
step 1 - 2.0 beginning of the diagnostic procedure part 1
Beginning of the diagnostic procedure we put on the diagnostic computer and compare the actual reading of the intake cam adjuster to specification. We watch to see how far the ecu adjust the timing retard and advance. We scan the ecu for dtc's and if we find a cam position code and a correlation problem between the cam and crank, we know the timing has jumped, broken guides, collapsed tensioners, possible stretched timing chain,sludge buildup, defective oil pump. If their are no dtc's relating to timing but the engine runs rough it is possible the balance shaft timing components have a problem either incorrect timing, defective tensioner, broken balance shaft, or stretched chain which can cause the engine to run rough and cause engine damage. Another common problem the 2.0 has is fuel injectors and carbon buildup which is causing engine failure and major engine problems.
step 2 - 2.0 daignostic procedure of part 2
The next step in the diagnostic procedure is to remove the cylinder head valve cover, the cylinder head timing chain cover, and lower timing chain cover. we install the timing tools and place the cams and crank at the correct timing position and if the tools don't lineup or fit then we do a visual inspection on the main chain components between the intake cam, exhaust cam, and crankshaft. We then check the balance shaft timing and components for something that doesnt meet factory specifications while looking for sludge buildup. its also recommended to remove the intake manifold and check for carbon buildup behind the valves and inside the manifold due to this common problem on the 2.0. Its recommended to do a decarbonization every 15k miles starting from new because the small carbon buildup can be easily removed at this point. But if it has not been done and carbon buildup is over excessively built, there is another solution called walnut shell decarbonization and we have the machine for this service. when a problem is found visually in the timing it is always recommended to do the full timing chain service.
step 3 - 2.0 diagnostic procedure of part 3
It is then required to remove all timing chain components and do a visual inspection on all the timing chain components and look for broken guides, defective tensioners, stretched timing chain, broken balance shafts, excessive wear on camshafts, excessive wear on camshaft bearing bracket, damaged adjuster, broken rocker arms, and sludge buildup. When the oil changes are not done at 5000 miles, the engine starts to buildup sludge and this can cause the tensioners to collapse and fail, cam adjuster to fail and not allow it to advance and retard the timing when the ecu demands a action, and guides get worn out excessively to the point that they become weak and bridle and break into multiple pieces which can cause a oil restriction anywhere in the oil lubrication system leading to more damage in the engine. Due to improper or lack of lubrication can cause the roller pins in the rocker arms to become worn out and disassemble from the rocker arm causing tapping, metallic, and clinking noises etc and lost in performance. Excessive carbon buildup causes injectors to fail and the engine to run lean and major engine damage can be caused such as burned or broken valves, valves to not seat properly causing misfiring, piston rings to get damaged and detonation in the cylinder. Because of a correlation problem between the cam to crank or carbon buildup we also do a cylinder leak down test to check for bent valves, broken valves, valves not seating properly, damaged pistons, and damaged piston rings etc..
step 4 - 2.0 repair procedure
It is highly recommended to do the full timing chain service which includes replacing the timing chains, timing chain tensioners, timing guides, cam adjuster control valve, fuel injectors, decarbonization, and sludge removal. For this engine their is many updates for these parts recommend installing the updated parts.