[Knocking sound NA engine Ninety]

The knocking sound is definitely by dropped hot spot. Its my third time in three years. Every summer one or two of them are dropping and damaging the pistons

[2.5 N/A Head Gasket replacement.]

hi,

Which de-coke set should be used? Any brand or online store suggestion. Because most of them does not contain valve caps.

[2.5 N/A droping hot spots :(]

Hi everyone,

I've s3 109 with 2.5N/A on it. My problem is, every summer head drops its hot spots on to pistons and causing me too much trouble. I own the vehicle since last 3 years, and with this year this is its 3rd time doing the same thing. Last year this lead to full engine rebuilt. This year only a blown head gasket and some minor dents on 3rd piston. So what is causing that drops hot spots. Since last years full engine rebuilt I've done only 3000 miles.