Mercedes V6 M112 Shocking Repair — Chain and Guides Replacement Revealed. • In this video we perform a full chain replacement and related components on the Mercedes M112 engine — installing new tensioners, guides, timing chain, and also the oil pump drive chain. To replace the guides in this V6 engine, both cylinder heads (left and right) must be removed. While the timing chain itself can sometimes be rolled in place without full engine disassembly, the guides are inaccessible unless the heads a