A small part that plays a critical role in protecting your 4M41 engine.
The upper timing chain guide and tensioner work together to keep the timing chain correctly supported, controlled and under the correct amount of tension. Over time, the plastic guide surface can wear or become damaged, while the tensioner can lose its ability to maintain proper chain tension. This can allow excessive movement, slack or chain rattle.
Why does that matter? The 4M41 is an interference engine. If the timing chain jumps out of position or fails, the pistons and valves can make contact, potentially resulting in serious internal engine damage and thousands of dollars in repairs.
The upper chain guide helps control the movement of the chain, while the timing chain tensioner applies the necessary tension to keep the chain running correctly and maintain accurate valve timing. Replacing worn components together can help reduce the risk of timing-chain-related problems.
For such inexpensive parts, replacing a worn guide and tired tensioner can be cheap insurance against a much bigger problem. Inspection and preventative replacement around 90,000–100,000 km may be worth considering, depending on your vehicle's condition, service history and how the engine is being used.
This is a genuine OEM Mitsubishi part from Japan – Part No. 1140A026 (Upper Timing Chain Guide).
We also recommend considering replacement of the timing chain tensioner at the same time – Mitsubishi Part No. 1141A045 + ME193622
