Moving on to the 2nd day of slow progress...
A new thermostat seal was ordered from Scuderia for a princely sum of £6 and we decided to change the oil, oil filter and the pollen filter thinking it would be easy enough...
A quick test of the thermostat did indeed reveal that it wasn't working properly
IMG_3754 by
Chris, on Flickr
Which confirmed the fault code - slow to warm up.
I've driven about 200miles init following all the work we did over the last few weeks and the hot start problem and associated drop into limp mode has not reoccured, so I think this was the problem and the engine management logic being;
Engine is slow to warm up.
It should be x temp after y amount of time given ambient temp of z.
Therefore there is either a problem with the temp sender under reading
or
The thermostat has failed.
Worse case is the temp sender is under reading and the engine is running hot. Therefore turn the engine fans on, limit power and over fuel the engine in order to protect it.
This is why we felt that the engine oil should be changed as it was likely causing some bore wash.
With the engine being dry sumped, it has two drain plugs. On in the oil tank which is located on the offside of the car at the front;
IMG_3739 by
Chris, on Flickr
IMG_3773 by
Chris, on Flickr
And the other in the conventional location;
IMG_3775 by
Chris, on Flickr
IMG_3777 by
Chris, on Flickr
The was about 4 litres in both the sump and the tank which were left to drain for a couple of hours. As well as lower one side and then the other, we also lput the wheel back on and lowered the car to the floor to ensure as much of it was realeased.
IMG_3771 by
Chris, on Flickr
The manual suggests that 7.3l of oil is required to refill it so dropping the oil whilst it was cold (no thermostat so we couldn't start it) didn't cause a problem.
There's nothing special about either of the sump plugs and the copper washers are a standard size which meant my Dad was able to provide some new ones out of his selection.
IMG_3779 by
Chris, on Flickr
Obviously the next step was the oil filter. Again, it is on the offside of the engine, mounted longitudinally along side the block - photo was taken from behind the front axle line, looking towards the front of the car;
IMG_3806 by
Chris, on Flickr
Access is relatively good for a hand, but it is all but impossible to get an oil filter wrench on it. Which is fine if it is hand tight.
As I am labouring the point, it obviously wasn't. It was silly tight and took 4 hours of swearing, removing brackets and 4 different types of removal tool to finally get the f:censored:g thing undone;
IMG_3817 by
Chris, on Flickr
The amount of damage to it is testament to the amount of torque it took to undo it;
IMG_3808 by
Chris, on Flickr
After making sure that the old filter was the correct part and the new filter was too, refitting the new one was a simple task - fortunately.
IMG_3813 by
Chris, on Flickr
The difference between two filters available for the 4.2 v8 is explained in the short video below;
The difficulty with refilling the engine with oil is, with it being dry sumped, the level is to be checked when the oil is warm (it expands). I expect that the specified 7.3l is enough though.
Just so that oil nerds know, I refilled it with the manufacturer recommended brand, which isn't cheap - 9 litres...
IMG_3823 by
Chris, on Flickr
( As a point of interest, the spider type (or planetary) oil filter tool in the above pic is the only one that could be used on the filter...)
After starting it and and rechecking it as it warmed up, it took about 8.2l to refill it which is about what came what out of it. And I've not had to top it up during the time I've had it, which is reassuring.