Recently at Auto Studio, an Audi Q7 was brought in after the customer experienced the car had lack of power and a rough idle.

Symptoms:

• Lack of power
• Rough idle

 What can cause a vehicle to have rough idle and lack of power?

Spark plugs, ignition coils, internal mechanical failure, faulty injectors, and air leaks just to name a few.  This vehicle was fitted with a diesel engine that had lost compression on 2 cylinders on the right bank which was determined by completing a compression test.

 How to fix a car a with rough idle and lack of power?

Further tests revealed that the valve timing was out due to a worn timing chain.

(Figure 1) shows the removed Audi Q7 engine.

Figure 1