UK Car Repair: car starts but only runs for afew seconds, vectra supertouring, cambelt

Question
hi
i was drivin my 1997 (r) vectra supertouring 2.5 v6 when it started backfirin through the air filter and lost all its power and eventually stopped and cut out with a horrible tapping noise coming from the engine.Ive checked the cambelt and it hasnt snapped or slipped.Ive tried starting the car it runs rough and only runs for about 10 secs,still tappin.Any information you can give me i would be very grateful.

THANK YOU!!!!!!!!!!!!!

Answer
This thing is sounding like it is going to be difficult and expensive. The backfiring is a timing issue and the knocking sounds are more likely than not a dropped valve guide or a collapsed piston caused by a valve impact. Take it to a garage and let them sort it out. It's the way to go in this instance. Whenever I hear the words knock, rap, tap, and ping, bonk, or screech described as coming from INSIDE the engine, I tell anyone who asks to take it to a shop and have a qualified technician look at it. This could mean a new engine. Have it examined immediately and don't try and start it anymore.

Sorry I couldn't offer more to help you in this situation but it would not be responsible of me to start going into things on repair knowing that it may be un-repairable and require replacement. Rendering all efforts to examine it or find the problem useless. Take it to the garage and tell them what happened and what it did. Don’t tell them about any checks you might have done, just put it in their laps and see what they say.

Good luck with it.

John