Hello i have a question today we were driving home on the highway pushing abuot 120-130km/h when sudenly the engile lost some of its power it still drove but he was on full trothle but was loosing speed slowly abuot 1km/h every minute or half lowest it went was 113 at the same time we lost power the ac started blowing only cold air after abuot 10 min the engine regained its full power and we were back at going 120~ but went strait to the neerest gas station after ariving we stopped and turned of the car and it statted smoking white out of the engine and had somewhat of a burnt ruber smell or atleast it smelled like that for me we wayted for abuot 15 minutes and just in case filled up on antifreeze there was no leaking from the engine or anywhere else and after waiting we drove again and it drowe like nothing happed just for clarificatiom the car is a 2004 toyota avensis diesel and while driving the temp gaude didnt show that it was overheating and no lights on the dash turned on. What is the cause?