today I put a AFM cold air intake on my car and the temperature went up to at about 90 degrees Celsius and when I let off of the gas it makes a noise is this a bad thing will it harm my engine?

Thank you

 

Fist check that you put it into the right place and that your intake doesn't just suck in the steaming hot air from the engine bay, check the manufacturers instructions for proper installation. Also for our B5 cars cold air intake does nothing at all. The stock air box is amazing. With the cold air intake you gain about 2-5 hp tops. Most other models such as acuras and hondas get a nice boost of 15+ to quite high, with yours and mine models they get next to nothing and is not worth doing. Read around no one recommends getting one, just get a new performance filter and your good to go. Try returning the one you bought.

The car is supposed to make lound intake sound when the gas is pressed when you let go, it shouldnt make any sound really.

 

put a proper heat shield if you cant get one use your stock airbox just cut it up. seen a diy for a b5 somehwere on here.