abentkov

I'm at about 280K on my 98 GS400 and its about time to do some preventative maintenance I was wandering what parts are required to do timing belt and water pump replacement. Belt, Water Pump, seals? tensioner?

Whether on D or N my car shakes like a monster. I took it to mechanic and his computer returned cylinder 1 3 5 7 misfire (whole left side). He checked for cracks on coils but non were discovered. We replaced spark plugs but problem came back once the car warmed up. He is telling me its the coils but i'm thinking - whole left side? Is this the way engine was designed or is there another type of relay or something that control the flow of whatever is required to create a spark. Any ideas? Has anyone came accross a problem like this? Its 98 GS400 with 280km on it.