norb:
Reference the cylinder head situation …i would imagine most of the engines would have been done by now …But a quick check is too look at where the head joins the block ,you should be able to tell if it has the latest multi layered head gasket ,if not sure ask .Can’t guarantee you will get an honest answer…Obviously as you have heard there is a lot of stories about heads on the XE/XF engine…Xe /XF is the model of engine,you will see it stamped on the engine id plate ,the fuel system is UPEC…So to dispel some myths …1…Ref the cracks on the heads at the rear beside the exhaust port.i can’t remember the figure but if it was belowsay 20mm it was deemed acceptable…Daf did a tweek to the casting that thickened the head where it cracked .Problem resolved .Their is a number on the casting that dictates it’s the tweeked head ,again i’m sorry i can’t remember it
2…Water/ oil leakage at the head gasket was resolved by fitting a metal multi layered head gasket,New head bolts must be fitted …May even come with head gasket kit…The only issue ever encountered with head bolts was when DAF had dealers recoat them …They never got an even coat and,with customers screaming for their vehicle and phoning DAF complaining about the service ,the coating would never get the 12 hours required for the sealant to cure before fitting them
3… Head bolt torque settings where changed for a greater clamping force
As an engine it is a pretty good unit as long as it is looked after properly …The only thing that is disappointing is the UPEC…Not the easiest system to diagnois ,and that is even for the dealers …But it is reliable ,it’s just when it plays up it can be at times a nightmare
The zf 16 speed gearbox is a good box only issue with them is 3rd /4th gear synchros,there a bit chocolate /soft…I have lost the count of the amount of synchros on 3rd /4th i have done on fleet vehicles…But i have only done a handful on owner driver vehicles ,so that tells a story in itself
Last but not least wiring …now i have said it i can hear others typing …looms are a problem …main problems are where they flex where the cab tilts ,look for botched repairs and layers of black tape…
The XF is a good truck ,all manufacturers have issues ,other manufacturers use the ZF gearbox …But to be honest if the wiring is good you won’t go wrong…If it has multiple repairs and exta wiring bypassing the original stay clear …Tacho wiring excluded .i personally reire it from the bulkhead to the tacho sender with rubberised 4 core ,it flexible ,and better quality than OE and never fails ,so far fingers crossed
Hope that is of some assistance to yourself
i was told 1" by DAF
very true
only synchros i had trouble with have been 1st and 3rd, the forward part of the box, never the backwards part
the only ones i have had wiring issues with have been 2005 models