406oc.co.uk

I strogly suspect that my cam belt has failed while at 70mph. Sudden loss of power followed by rapid [machine gun fire] mechanical, tappet like noise [valves hitting pistons]? RAC man checked injector pump no output? Could it be fuel lift pump? I will have the belt cover off later this am.

I have mechanical experience so I hope to be able to repair it but seek advice and have a few questions.
1 I once had a citroen that blew it's head gasket. After replacing it I was advised that these and some other modern engines did not take head removel well and were prone to further problems. This occoured despite preasure testing and skimming the head. Why was this and is my 406 likly to be the same?
2 Should I have the head skimmedas a matter of course if I take it off .
3 Will the valve guides be likly to be dammaged?
4 Would you recomend I give the head to specialists for recon work?
5 Is damage to the bottom end likly?
6 If it is the cam belt should just look for another engine.
7 Will I need Tx sockets or special tools? Haynes manual?
8 What have I done to deserv this? [ If you are god you can anser this.] I only just bought it [Private sale] and they told me it had been done [Living and learning is a lifelong thing ].

Thanks for reading. Ian Parker

Sounds serious Mate!
I will share my limited experience of working on modern cars.

Head recon,

Get a breaker spare or professional recon. To try and o/haul the head and replace the valves your self can be done but the effort required and the end result of not knowing exactly how good the seats are (unless you NDT them) make it a no brainer in my book. (I mention the valve seats as I did a head on a Renault scenic 1.6, only to re-install it and have the engine fail after 30 minutes. I had no way of NDT'ing the seats and had missed a hairline crack whch caused the seat to drop out get mashed and punch through the piston

It is unlikely that the bottom end will be damaged, however you may find a gaping hole punched through one of the pistons if the valves have failed big time.

A new engine may be the way to go, however you will have the ball ache of intalling said item.

My course of action would be:

1. Take off the oil filler cap and have some one spin the engine over, it the cams move you are not looking at atiming belt.
2. If the cam shaft does not move, whip the head off (You will need male and female star bits for this).
3. Look at the valves if they are bent (which they almost certainly will be!) have the head re-con'd if you can afford it, if not get a head from a breakers.
4. New head gasket, belts and tensioners need to be fitted!
5. Install new head and retire to the kitchen for tea and medals!

Good luck

PS It's freezing out side, I would be tempted to close the garage door and buy a new car!!

Nice post! I've got nowt to add other than go buy a Haynes for the torque settings etc. and only skim the head if necessary (if you'e fixing the old one take it along to a reconditioner to have it measured, it might have been done before).

its also not unusual for the swirl chamber(s) to drop out of the head on to the pistons, and destroy the engine