I got a knocking in my engine, now it's miss firing, on 2006 Volkswagen Golf TDI

My car was in tip top condition, then I got a little knocking but went off after a few mins, then few days later it did it again, now it's on all the time , also now it's miss firing,also the knocking noise got louder, I took it in for a check up, I been told timing belt. Then injector , then tappets, then valves, I'm con fused dnt want to start changing things that dnt need changing, a good garage can't see it till next week, I need my car for work , it's dne 160.000 is any thing that is comments that cud be gone,

by in Tacoma, WA on March 22, 2013
1 answer
ANSWER by on March 22, 2013
use oil stabilizer in engine to recondition seals pull fuel filter, check for water. use ethanol treatment to clean fuel system. upgrade air filter to high flow filter type(K&N). knocking sound some times air/fuel mixture. pull coils and plugs. you are looking for damage to coil boots and wear to the spark plug tips. if prob with coil boots you should be able to replace them as opposed to replacing entire coil. upgrade spark plug to premium type. if not confident in shop that looked at it, get second hands on opinion(especially the timing belt). most of these are things you can do your self to cut cost.