I recently had trouble starting my Volkswagen Golf 1.6 mk4 on a very hot (35C) day.

It made a loud grinding noise. I called road side assistance and by the time they got out the problem had stopped.

This happened a few more times on very hot days until the car stopped turning over all together.

I took the car to the mechanic to get the starter motor replaced - it was totally stuffed. The mechanic said he had seen this happen before so he put a relay in as well as a new starter motor.

There was a small amount of damage done to the ring gear resulting in a small noise upon starting.

He assured me that this will not result in any extra issues.

However on another hot day the car made the grinding noise again. The noise subsided once the car had time to cool down from the suns heat.

The car works fine in normal temperatures. It is only on hot days that the noise seems to appear.