Good day guys

My name is Gerard I have a 2007 Toyota Runx TRD please go google it...Really a smart looking car. It has a 2zz-ge engine in with a 6 speed manual gearbox. The car standard Toyota rating made 141kw which is about 190hp I don't know which celica has that spec 2zz in it. The TRD version was done by TOYOTA SA only made 200 of them only cosmetic changes over the normal runx rsi. This forum is really cool and really helpful. Just had a question about the car and im sure you guys might know in the morning when I use the car if I change into 3rd gear it sometimes grinds into 3rd gear. When the engine warms up though it doesn't grind at all. What could be the cause of that?

Thank for your help
Gerard