Audi A3: squealing noise coming from the engine compartment at idle speed

Autodata Company runs Autodocta guide, where solutions to common, but difficult to diagnose, automotive problems are presented. This time the problem discussed is the squealing that occurs just after cold engine ignition.

Our customer owns an Audi A3 from 2015 with a 2.0 diesel engine and complains about a squeaking sound coming from the engine compartment when the engine is idling. We heard this sound during a cold start of the engine, but already in the workshop we have a problem with determining the cause. Do you know what could cause such a noise?

Answer: Yes, we have already heard about this problem, which concerns A3 models from 2013-2018 with CRLB/CRLC engine codes. The cause of the malfunction is a defective design of the timing belt tension roller, which has a negative effect on timing belt wear and creates a squeaking noise. Check the timing belt tensioner (fig.1.1.). If it is a timing belt tensioner from a brand other than Litens, install a new timing belt tensioner. When changing the timing belt tensioner, it is recommended that the timing belt is also changed. After the repair is completed, a test drive should be performed to see if the fault has been removed.