JustBadly

TPS Jaguar fits onto the manifold body. Easiest thing ever to change and yes it is a potentiometer.

Liar liar, your exhaust is on fire

The serpent belt is a challenge and firstly take a few pictures of the routing to reference when fitting. Use a 12" adjustable spanner to relax the tensioner, it fits nicely on the tensioner and gives good leverage. Lever the tensioner and slip the belt off the pulley, then ease the belt off and out from the motor.
Use this opportunity to give the front of the engine a degrease.
Fitting the new belt can be made far easier by using a bungee cord to pre-tension the belt prior to placing around the tensioner pulley. Loop the belt over the crank pulley first followed by the rest of the pulleys excluding the tensioner. Position the belt loosely around them and lastly (the important bit) hook the bungee cord onto the belt near the tension pulley and attach the other end remotely to apply tension. 
Now examine each pulley to check the belt is seated correctly, the slight pre-tension will prevent the belt from slipping off other pulleys should you need to reposition the belt.
Once seated then use the adjustable to lever the tensioner pulley and slip the belt on... et voila!

I have looked at 2nd hand actuators but will be buying new since the price difference is not that great. Also an actuator from an xf is still 10 years old so the chances of it being worn are high. Part number for new(!) Parkbrake is C2C40572, which is suitable for:-

S-Type VIN range: From M45255 to END OF RANGE
XF VIN range: From START OF RANGE to R47153
X150 (Except Portfolio models) VIN range: From B00379 to B33388
X350 VIN range: From VIN G48774 to H30499 (2002-10)

Naturally, you will think how wonderful there are all these Jaguars that have a compatible part. But chasing them on the well known auction site brings us back to the same former conclusion. It's a weighty job that would be super disappointing to find that the replacement is no better than what you removed. Additionally I will replace the external bolts with stainless and paint the Aluminium, with an extra coat for the steel motor casing when I receive the new actuator. 

Had opportunity this week to install the new radiator and not before time. Judging by the date stamp, I have removed the original radiator. As you can see the old one is seriously damaged although not leaking.
The new radiator temperatures are Water in 88°c, Water out 55°c, Transmission fluid line (upper) 40°c. Air temperature 18°c. The radiator fan switches on more frequently at low speed but this probably means it is working properly.

Anyone know if the dip/main beam switching can be changed? Currently when the lights are on dip is always on, when main beam is on, dip is still on. Looks like a rally car. I was wondering if factory options can be changed via the OBD2 port.

Clock spring requires to be 'set' so many turns out from stop. If the sensor hasn't been fitted correct then it won't give a proper reading.

For DSC error check rear wheel abs sensors for starters.

Change the spark plugs.

Yes put the pictures up anyway. I'd guess you will have used offset ring spanners to loosen the 18mm bolts on the rear of the diff. One question, are the actuator 10mm a/f hex nuts 'attached' to the inside of the sub frame? I would expect them to be.

A sticky on another Jaguar forum recommends dropping the differential and accessing the parkbrake motor from there. Looking to do mine this year since the inspektor said it's operation is erratic. Though looking at the design, if I had my way the parkbrake motor would be in the boot, underneath the side trims, there is enough room there!

The reinforcement has been completed, I am going to fit it when the weather's warmer. As for 'designed splits' I think it is only part built - now all the extra metal is on I can sit on the radiator now.

Yes, when the engine is cold and gets up to 5th, force 4th or lower and it should go away. Last time I asked a garage for ATF change they wanted £630. If you can do it yourself I think you should.

So you mean that when the engine is cold and you reach about 30mph there is a rhythmic rumble or growling from the centre/rear of the car and when warmed up it goes away? The transmission fluid is low (it's the gears resonating since the rpm should be higher).

Have a look at the workshop manual for a quick guide, the schematics will show you any major differences. Having said that, with one engine having VVT I doubt very much if you will find them comparable. The VVT uses a grooved cylinder that is actuated by Oil pressure, which in turn is controlled by a solenoid. This thrusts toward the cam, altering it's timing. Each cam has to be aligned perfectly along with each cylinder bank if it is stripped.

If you are planning on porting heads I would not carry on with a 4.2 head hoping it will somehow mate with the 4 litre block. Try your luck with the 4.0 head, it will be plenty fast.

I bet the Adamesh silencers run at a higher temperature and cut out the exhaust fog in freezing conditions. I am quite tempted to buy a set of these pipes in 2020 but one question, I hope they will not trigger noise testers on a trackday or the new roadside decibel meters when they go live?

Recently I solved a water leak from the pipe union between the expansion tank and water hose. This was dropping coolant and in turn causing the alternator to become soaked. If the windings are wet then sparking will occur and the charge output will drop. Now the engine bay is dry again I noticed the battery charge has improved and I can put off buying a new battery for the time being. 

I really think s-type owners should check around the top of the radiator and the fan housing for any sign of water and if found deal with it, this is particularly relevant to charging issues.

I have recently purchased a new radiator since although the current one has not failed, it has curved at the bottom and I figure it won't be too long before a leak occurs. What I am going to do is reinforce the new radiator by placing aluminium bar top and bottom of the radiator core and a strut length ways to try and prevent this happening again. I will use zinc-alloy brazing to attach the various aluminium bar and plate, since the zinc-alloy melts at 400°c and should provide a suitable and strong filler. Not going to TIG since I am a beginner at that. Wish me luck, I will work on the radiator around Xmas time and install it when the weather is warmer and will post pictures.

I have found Avon tyres to be offering some of the worst quality tires out there, wear rate is uneven, low mileage, perishing and even bulges from tire wall damage. Only slightly better than the Chinese brands and 4x the price. I have Toyo tires fitted on my Jag and they are a good all-rounder and half the price of the big 3.

I have just fixed a water leak on the Jag and it's sounds very much like the one you have. Took months to find it since the leak was only when engine running and from ..... the pipe union between the water expansion tank and hosing. Someone had used radweld so the leak was 100ml per week or so. I spotted water on the frame under the radiator and since the radiator appeared sound I suspected the expansion tank. After wiggling pipes the leak was much worse so I stripped the tank and hoses. I decided to make an 'O' ring for the pipe union and placed it on the 45° ramp with some white pipe tape for good measure. Much grunting later and the leak is fixed! 

Front pad replacement is simple but heavy work. While you are at it buy new bleed nipples for the brake calipers. You will need a piston rewind tool, they are stiff !Removed!'s. When you have the job set up and are ready to rewind the pistons, loosen the bleed nipple until hand tight. Then as you rewind the piston loosen the bleed nipple so the brake fluid drains out (all over the floor). Once fully recessed, tighten the bleed nipple. This dumps the brake fluid nearest the pad - which will be seriously out of grade. When the pads are in and wheel on, pump the brake pedal till firm and top up the brake reservoir with new fluid. This is a quick and reliable way to 'bleed' the brakes.

This tearful account of transmission woes has me telling you my tale of recent Jag ownership. When I bought the car (private) within a few miles I noticed a rumble when going over 30mph coming from the floorpan/transmission area. Using it for the commute, the gearbox was terrible until warm, then just about bearable - almost comically bad. Now I am a biker, and have been for many years and one thing we bikers are used to is; a multi-plate wet clutch. And one thing these clutches are sensitive to is; fluid level. I was fairly sure I would have me a good transmission once I got around to replenishing the fluid.
So I got the kit together and force-filled the zf with 7 litres of lifeguard and the transmission has been wonderful ever since (as I expected). The trouble is that the refill instructions (fill until Oil seeps out of the refill port - start engine, do again) only manage to put 2.5 litres or so into the 'box and that will never cure the problems manifest.
Now I wanted to add an extra litre to the transmission but didn't want to drain/refill the transmission in order to do this. So after a while I thought about adding fluid to the zf via the Oil cooler in the unified water radiator. Going 'in' by the upper hose did not flow but the lower hose allowed fluid to be introduced albeit at a very slow rate, about 1 litre in 30 minutes!
My point is - if the rumble is apparent but the gearbox functions well when warm, add fluid the way I have described until it goes away and forget garage advice - they do not have the correct service instruction.