I have a Volkswagen Polo 6N Petrol 1.4 8v 60cv from 1997 with 168 000KM.
It's my only car and I can't afford to get a new one. It's been looked after and has been in the family since new. I have been having some problems with it and I would like some help, if possible.
One problem is with the engine. Something odd starts to happen when driving on hot days. For some reason, when the car starts to reach the normal temperature it starts to lose power. This is more noticeable when accelerating. I can associate this loss of power with the engine reaching normal temperature for this reason: the car has no thermostat. In winter, when temperatures are near 0º C, the car runs constantly cold and drives smoothly and with all the power. The same thing happens during summer right after a cold start, it starts well but loses power when it gets to normal temperature.
Another problem I have is with the gearbox (I think?). Sometimes when I accelerate I can hear a buzz like a whistle. This happens more frequently in 1st and 5th gear. Once, on a long drive with four people, the buzz started to become louder. There were two times on that trip that when the fifth gear jumped to neutral. A mechanic changed the gearbox oil and said it had no metal pieces on the old oil.
Also, I obtained the following error code from the car:
00524 - Knock Sensor 1 (G61)
31-00 - Open or Short to Ground
I’m looking for any advice you can give related to these two problems I’m facing.
Thank you in advance.