W12 Thermostat Swap

[david@a8parts]

A month or so ago I decided to change the thermostat on my W12.
During the summer I thought it was quite slow to warm up compared to my previous W12, but I put that down to the SWB having an extra radiator and therefore larger capacity cooling system, more water etc. I thought at the time I was being optimistic (the extra radiator *shouldn’t* make any difference as it should technically be at the other side of the thermostat), but carried on crossing my fingers and hoping it wasn’t the thermostat because I had heard what a pain of a job it was.
As the temperature dropped it was obvious something wasn’t right, on my 12 mile journey home I was lucky to see the temperature needle move a quarter of its travel, and it certainly never got anywhere near 90 degrees. Add to this a measly 240 miles on a tank, and worse still the heater struggling to keep me warm, something had to be done!

Ordered the thermostat from TPS which arrived after a worryingly "its on back order" week and a bit!

Started the job on a Saturday morning around 10Am and to be perfectly honest it wasn’t difficult at all. I followed the instructions which in a nutshell are drain coolant, remove upper inlet manifold and then remove lower inlet manifold. At this point I was a little nervous about the fact that I could see the valve stems through the inlet ports on the engine so rapidly stuffed tissue into any hole that looked like I could drop something into!

Once this is done the 'thermostat' is visible and can be quite easily removed and replaced. It is a fairly complex affair compared to the simple circular mechanical devices you find on older cars but even so it was a fairly simple swap of a few pipes and one electrical connector.

Refitting is reversal of removal as the saying goes and carefully putting the whole lot back together was more a job of patience than anything else, double checking each hose and pipe was reconnected as it should be (yes I removed the tissue !)

Refilling the coolant system was easy too, the additional electric coolant pump making it easy to get rid of any air. All done by 2pm.

And what a difference! The engine is up to 90 within the first 2 miles and the heater works so much better - sadly the fuel economy has not altered in the slightest, but at least the heat generated from all that fuel can keep me warm now

I know a few of you have intimated that I would be breaking the car as soon as I came up against a problem that needed either time or money to fix, but I really don’t think so with this one, it’s a keeper, and has its place booked in the '8 museum collection next to the Pearl S8 (eventually!)

[david@a8parts]

Sorry, not very good with photos, but you will see in one of the pics that the wires to the injectors are labelled with yellow tags. These are put on at the factory so that when you disconnect them you can get them back in the right place. Excellent theory, however, the guy who labelled up my engine loom got a bit carried away with the number 5 stickers and accidentally labelled both number 5 and number 6 injector wires as number 5! Consequently I had a small panic when it came it reconnecting them, luckily it was obvious from the length of wire and the shape of them which one went where.

Sometimes it is nice to see human error on something that you would expect to be so automated.....

[Architex_mA8tey]

good job David! at least youll not freeze into winter now. . .
By the way you didnt keep ALL of it as a keeper - a small part of that W12 will live on my car in the form of its Calipers sometime soon hehe. Got the Bentley cover plates now and getting the Calipers painted black next. Will try and phone this week to sort out the hubs with you or carl

[daviesbike]

I totally think that its myth that the W12 is hard to work on...every job i do on the w12 is straigh forward its easy to maintain and service ...ive just changed 1 injector on the fuel rail and also took them all off and give them a good clean up while i was there to make sure it was tikkity boo



Injector rail on

And off



Just followed this ....




Why are people affrade of the w12 ?....
Next job gut the cats ...re map and lpg

[A8 Doc]

Good on you. LPG for sure but remap first so they can match and if needed oversize the injectors to suit :thumb: