Peugeot 106 (1991 - 2002) - Cylinder Head - Cracks between valves (diesel)

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Sat 15 Dec 2007 16:31
Cylinder Head - Cracks between valves (diesel) - firejuggler
Hi, thankyou for the useful advice re cam belt tensioning but have hit a major problem possibly design fault with the engine. On close inspection of head i noticed cracks between each valve in each combustion chamber. After much phoning around breakers all I could get was a complete engine. I took head off to swap them and this one is cracked in the same place!!! Is this a common problem? I'm at a complete loss as to what to do cos any further engines may also be knackered and car although in good condition (apart from head!) is only worth 500 quid! Any advice is truly gratefully appreciated.

slt

Edited by Pugugly {P} on 15/12/2007 at 16:59

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Sat 15 Dec 2007 18:32
Cylinder Head - Cracks between valves (diesel) - 659FBE
Head cracking is not unknown on high mileage diesels but generally occurs when the engine is run with a low level of coolant. A further joker in the pack which applies to many PSA installations is poor venting of the cooling system. This can result in there being no coolant at the hottest part of the engine, with obvious resulting damage.

A well designed cooling system will have a "degas" line from the highest point in the system to the top of the header tank where air and vapour can be automaically vented out. For this to occur, the water pump and the make-up feed from the header tank have to be positioned such that the pressure drops give a small circulation via the degas line.

Many manufacturers have got this wrong; the presence of a vent screw other than on the heater line is a sign of bad design. I hope you find a good cylinder head - check that the pre-chambers are free of cracks and secure in the head also.

659.
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Sat 15 Dec 2007 20:52
Cylinder Head - Cracks between valves (diesel) - madf
The 106 diesel is notorious for a poor design of hoses... with bleed screws in them. The cooling system is fragile and requires weekly inspection. The radiators corrode as well with age and salt.

I assume it's a 1.5 diesel.. see tinyurl.com/3akuxe


madf
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