Timing chain stretched – a common reason for Range Rover 2016 2L engine failure
The 2L engine is fitted in several Range Rover models, such as Evoke, Discovery, and Range Rover Sport. This car came with a permanent engine rattling noise. The reason is a “stretched” timing chain.
The timing chain is a critical part of the engine that synchronises the rotation of the camshaft and crankshaft. The timing chain controls the engine’s intake and exhaust valves. These valves must be opened and closed in perfect coordination with the movement of the pistons, which is essential for proper and efficient engine operation.
Timing chain stretch is not the ‘stretching’ of the chain; it’s an elongation of the timing chain caused by wear in the chain’s components.
The most common causes of this phenomenon are:
– the natural wear of the chain and other components. The timing chains are extremely durable but do not last forever (see the Owner’s Manual for details about the timing chain replacement interval!) or
– poor chain lubrication due to a lack of maintenance. When maintenance intervals get longer, the oil becomes contaminated with dirt, fuel, and metallic particles changing viscosity and no longer lubricating as it should, causing accelerated wear to the chain(elongation) and the timing system components.
What happens if your timing chain is stretched?
On a new chain, the tensioner should only be slightly out. The hydraulic tensioner quickly compensates for chain tension variations due to engine temperature. When the engine heats up, the chain will stretch. The hydraulic tensioner automatically adjusts the applied tension to prevent the chain from slipping and avoid engine damage.
When the timing chain is stretched because it is worn, there is no pressure in the tensioner at start-up or idle. This can cause engine starting problems, lead to engine misfire while driving and/or the chain making a rattling noise for a few seconds at start-up. When the tensioner applies pressure on the chain, the noise disappears.
What will happen if the vehicle continues to be driven this way?
The chain will wear more and more and become less tight. The tensioner will no longer be able to tension it; the rattling noise will be permanent(like in our case). This can be seen in the photo below, where the tensioner can no longer exert pressure on the timing chain.
Driving with a stretched timing chain is very dangerous because it can cause the vehicle to stop at any time without warning or cause catastrophic engine failure such as bending valves, damaging the camshaft, pistons and so on, ending in an extensive and expensive repair.
If you hear strange rattling noises, have troubles with the start-up and experiment engine misfires, it is always best to take the car to a mechanic immediately to avoid severe engine damage.
This car has two timing chains. The upper one drives the camshaft from an intermediate shaft and the lower chain from the intermediate shaft to the crankshaft. Even with several chains, the operating principle and problems are the same!
As seen from the photo below, a tooth of the intermediate shaft sprocket is broken.
In this case, our customer was very lucky! Changing the stretched chain and timing system components(if needed) is expensive but definitely, less expensive than rebuilding or replacing the engine or buying another car if the engine is severely damaged. Pay close attention to strange engine noises! If small faults are repaired quickly, avoid major damage and high expenses. Our team of experts can help you with timing chain problems.
More details in the video below: