Cylinder head reconditioning?

[zedder]

My 1998 Puma was running on 3 cylinders. I got a phonecall from garage today after they had removed the cylinder head and reason for this problem was as expected: one damaged exhaust valve. Quite large chunk was missing and there was also a small mark on top of the piston.

Now I have a question:

How comprehensive recondition is reasonable? Should I get all valves replaced or just the damaged one? How probable is that another old valve will break soon? What else should be done when cylinder head is removed? Cam belt and it´s tensioner will be replaced of course.

On Monday I´m gonna go to see the cylinder head myself and then I have to tell them what to do.

 

[LOONEY]

change the head on it

 

[zedder]

change the head on it

Can´t do that in this country and with this deadline...

 

[LOONEY]

why what country are you in

 

[zedder]

why what country are you in

In Finland.

It would be very hard to find a good used Puma cylinder head . It is possible to order one From Germany and UK, but I have no time for that right now. I need my Puma back on the road as soon as possible and that´s why old head has to be used. Only one valve is broken, so it won´t be necessary to replace whole cylinder head, right?

 

[DOH]

you need to check that the valve seat in the head is ok, the valve seat may need to be recut or even replaced by an engine machine shop. you should also get the head refaced with a minimal skim.

The important thing with any engine failure is to find the cause. If you don't it may fail agin. If the valve has splintered, then that may be due to it overheating, due to too lean a mixture. I would recommend you also check that the valve clearances weren't to tight. I recall it failed after a motorway run. Perhaps the fuel filter on the petrol tank is clogged or the injectors need cleaning. Also plug in a diagnostic to see if there are any fault codes. Otherwise the repair might not last long

 

[zedder]

I think I have to trust that the garage takes care that broken valve is replaced correctly.

I have heard 2 different opinions regarding if replacing all valves is necessary/wise thing to do. Is it? Or is it overkill?

Yes, there must be some kind of reason why valve was damaged, too lean mixture might be it. And I think garage must check valve clearances when they install camshafts.

They plugged diagnostic tool (Bosch) in the socket and there were codes that told about misfire (?) in cylinders 1 and 3 if I remember correctly.