I am sure we have all seen this!

Customer starts car to turn it round, back it out of the garage, whatever. Stops it, comes back 5 mins later and it wont go!

(Symptoms are total loss of compression on all cylinders)

Most of the time, one can get them to go again with a bit of delft foot work, (Sometimes one has to short out the CTS to un-flood the engine)but most owners these days have no real experience of starting reluctant engines (unlike people like me who lived back in the dark ages!) and they just dont have a clue how to do it.

This problem can arise on cars that have been meticulously maintained (I have had it with regular customers and even one of my own cars once!) so it is not necessarily a maintenance problem.

It isn't even always a problem with engines with hydraulic tappets (I have had non-hydralic tappet cars have this problem)

Is there a definitive explanation for this? I am guessing that it is a valve problem. But it NEVER EVER happened to the cars of the 60/70/80's which I grew up on!

And is there any definitive way of ensuring that it wont happen again??

(I am not holding my breath! Personally I think this problem represents a fundimenatl weakness in modern motor engineering and is essentially unsolveable! It is just one of those things that will happen from time to time!)

My own advise to custmers is DO NOT switch off the engine unless it has run for at least 5 mins from cold! (Especially if it is a Volvo or a Jag (And from today, a Toyota Celica!!!!))

Paul.