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2003 Mercedes Benz C 240 4MATIC Sedan (203.081) V6-2.6L (112.916)
Replace Timing Chain
1 Disconnect ground cable of battery CAUTION: - Do not connect quiescent current retention device otherwise this may cause damage to the control module. 2 Remove spark plugs NOTE: To ensure that the engine can be easily cranked when drawing in the timing chain, and to avoid the timing chain jumping across. Remove only once spark plug of each cylinder. 3 Remove cylinder head covers - Air cleaner mounted on vehicle - Air cleaner positioned at engine side 4.1 Remove fan shroud NOTE: Not Model 211.061/065/070, 230.475 4.2 Remove electric fan 5 Position engine to 40 degrees after TDC of first cylinder. NOTE: - Engine must not be cranked backwards. - The notches of the camshafts must point toward the inner V. - It must be possible to easily insert the two locking plates. If this is not possible, Set the basic position of camshafts. - The copper plates of the timing chain must be aligned with the scribe marks on the camshaft sprockets. - Owing to the unevenly long paths of the timing chain it may be necessary to crank the engine as many as 14 times till the copper plates get aligned with the scribe marks on the camshaft
sprockets. - On vehicles equipped with an air pump, the combination valve must be unbolted before the right locking plate is inserted. - Installation: Replace Gasket of combination valve. 6 Remove chain tensioner 7 Remove camshaft position sensor 8 Crank engine in direction of rotation until the link for separating the timing chain is easily accessible NOTE: Timing chain is separated one chain link next to the copper plate (on right). See new timing chain. 9 Remove camshaft bearing bridge on right 10 Install holding bush (3) onto camshaft on right NOTE: Screw in bolts (4) only until they touch. 11 Attach retaining devices (1, 2) for timing chain to right and left cylinder head 12 Separate timing chain CAUTION: Cover over timing case recess with a clean cloth. Parts which have dropped into the timing case recess, must be removed. NOTE: To pull out the old timing chain, connect the old chain to the new timing chain. Install 13 Draw in new timing chain NOTE: To draw in the new timing chain, crank engine in direction of rotation at the crankshaft. 14 Remove retaining devices (1, 2) for timing chain at right and left cylinder head 15 Rivet new timing chain
16 Crank engine in direction of rotation 17 Check timing of engine 18 Take off holding bush (3) on right camshaft 19 Install camshaft bearing bridge on right 20 Install camshaft position sensor 21 Installing chain tensioner 22.1Install fan shroud NOTE: Not Model 211.061/065/070, 230.475. 22.2Install electric fan 23 Install cylinder head covers - Air cleaner mounted on vehicle. - Air cleaner positioned at engine side. 24 Install spark plugs 25 Connect ground cable DANGER: - Risk of accident from vehicle starting off by itself when engine running. Risk of injury as working around the engine during startup or while running may result in contusions and burns - Secure vehicle to prevent it from moving. - Wear closed and tight-fitting work clothes. - Do not grasp hot or rotating parts. 26 Run engine and inspect for leaks.
General notes on timing, markings
The four copper plates of the timing chain facilitate the assembly when putting on timing chain. Each copper plate (1) must be matched with one of the markings (camshafts 4/ 5, balance shaft 3 (M 112) or guide wheel 3 (M 113) and crankshaft 2). Due to unequal length of timing chain paths, the engine must be cranked up to 14 times, until the copper plates are matched again with the markings.
Screw diagram for timing case cover
Remove/Install Chain Tensioner
1.1 Remove fan shroud (2) together with electric fan 1.2 Remove electric fan 2 Remove generator (G2) NOTE: On generator (G2) only unscrew upper bolt, slacken lower bolt. Only move generator away. 3 Take chain tensioner (6) off timing case cover(5) NOTE: Installation: Replace seal (7). 4 Install in the reverse order.
You will need special tools to perform this job
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Chad FarhatASE Certified Technician
I will open up the question for you for another expert maybe they have better directions & diagrams , I m sorry that is all I have on it for timing chain.
Hi thaanks for using justanswer.com. Like the Tech before me said this job does take special tools. Not to insult so dont take it the wrong way. Its not a job for novice. Here are the instructions that Mercedes has released.
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If you have any questions on these steps. Let me know. I will be on and off for another hour.
Just checking in to see if you needed anything else? If I was of some assistance please accept and rate as this is how we are credited. If you need any further assistance let me know. Thank you.