With the DPF light illuminated on the dash, the owner of the Mazda 3 2.2 diesel booked the car in for diagnostics. The owner of the car had previously taken the car to another garage for diagnostics. They diagnosed a stretch timing chain. Not feeling confident in the diagnostics and concerned that the garage was trying to pull a “fast one” they came for a second opinion. After a full system scan we eliminated a blocked dpf filter and confirmed a stretched timing chain.

With the timing chain kit ordered the Mazda was booked in. The primary purpose of timing chains in a vehicle is to make sure the engine’s valves all open and close at the correct times. A timing chain is essentially the same as a timing belt but generally speaking has a much longer service life. It is important to follow the car’s service plan and replace the timing chain per the manual’s recommendation. Replacing timing chains before they break is cheaper than replacing an engine afterwards.

The job of stripping the down the engine began. Quite a lot of the engine bay area are needs to be removed to get to the actual chain. Once we had cleared the area we could see the chain and tensioners.

With the chain removed we compared it to the new replacement and we could see that the old chain had stretched.

With new timing chain kit fitted, the car built back up and the ecu re-calibrated the dpf engine light disappeared.

How do you know if the timing chain is worn?

In the case of the case of the Mazda, the dpf light was flashing. But other signs that the timing chain is worn the engine may feel sluggish, low on power or have troubles starting. This is because as the chain wears out, it stretches and the ignition and valve timing becomes more retarded.

For more information or to book your car in for a timing belt or chain get in touch