For months I've been trying to correct an engine warning light which comes on intermittently, with the following message “Drive system malfunction, contact service"
Also from the pictures you will notice that the tachometer is red above 4000, which means my speed is limited to 4000RPMs when the lights come on. a mechanic told me The engine is protecting itself., I can only drive up to a certain max RPM (loss of power)Engine Speed Limitation, I can only drive up to a certain max RPM (loss of power)

So far I've replaced a water pump and the water resevoir. Looking for suggestions as to what the problem might be.

My Audi only has 30000 miles and I live in the US virgin Islands with no access to qualified Audi mechanic