We bought Kim, my wife a 53 plate V8. On closer examination it has had a new bumper and nearside headlight assembly. The bumper was not quite aligned correctly, now it is pretty close and the headlights were way off, now they are not too bad. The metal is all straight and no bent bits of framework. However there is an issue with the heating. Nearside blows hot all the time and offside works as it should. My guess is the dccv heat control valve and maybe rccm will need replacing. Then I had another thought is there a connection to the dccv near the bumper. Could it have been reconnected with a bad contact on one solenoid when the bumper was being replaced?
It would be nice if it were this. Incidentally the V8 is very smooth and uses less fuel than my 3.0l manual at a decent speed. It rolls a bit more and feels a bit more inclined to understeer but for a long journey it will be the pick.

 

It could be a bad DCCV (common, not Bosch's finest product) or bad wiring. You can to some extent meter it - if you can get at the connector.

There's a chance the bumper was off to fix a bad harness and/or caused a harness fault.

The NA V8 is a lovely engine so whatever's wrong is IMO well worth figuring out.

A bad DCCV sadly tends to draw too much current, and then takes out one or more parts of the RCCM (easy access behind glovebox). Usually "just" PCB trace(s) which can be fixed by anyone with a clue and a soldering iron.

 

Agreed it is just soppy bits that need a bit of attention. The gearbox engine and body are all in good condition so once these silly little things are sorted even at the cost of a few hundred pounds Kim will have a magic car.