How to Freshen up a used V12?
 

Looking for some advice.

I just pulled a used V12 out of an '85 XJS. The car had been sitting for many years. I heard the motor run before it was taken out and did not hear any bad sounds.

If the compression on each cylinder checks out OK I plan to do the following;

REPLACE

Oil Pan Gasket
Valve Cover Gaskets
Intake Manifold Gaskets
Fuel Injection Hoses (and any other rubber hoses)
Thermostats and gaskets
Sensors (as needed)
Cap, Rotor and Spark Plugs
Spark Plug Wires


SHOULD I REPLACE?

Oil Pump
Water Pump




What other parts should I inspect/replace before I put this engine into my '89?

Thanks!

Mark

The oil pump will be fine. The water pump probably will be. It is easy to change engine in car, so see if it leaks, if not, no worries. All the other things you mention are very sensible to fix.

Is your 1989 car a Marelli ignition car? if so, the loom and ECU and other bits will be different from that used in the Lucas ignition 1985 engine.

Greg

Both engines are Lucas so no problem there. I will replace/recondition all wiring looms before installing the engine.

While the engine is out of the '89 I also plan to repaint the engine bay and clean/replace all of the parts that are mounted to the firewall and fenders.

Should be beautiful when I finish!

Mark

This is probably on your mental list but in case it isn't.....

Make sure that the vacuum and mechanical systems in the distributor are working, and working properly.

Check motor mounts...although it seems like we almost never hear of problems/failures.

Cheers
DD

While you're at it, be sure to replace the half moon seals at the back of the cam towers, preferably with something more permanent than the original rubber plugs. I filled them with JB Weld on one of my motors, and with Ron Kelnofer's aluminum half moon seals on the other motor. Also, replace the Oil Gauge Transmitter PN C46272, and the Oil Pressure Switch PN C42200. Both are known to leak in their old age, and are much easier to replace while the intakes are off, than with them on.

On the bottom of the motor, it is pointless to replace the oil pan gasket unless you also replace the sandwich plate gasket, as it is more prone to leaks than is the oil pan gasket. There is also a gasket and some O-rings for the side mounted oil filter housing and plumbing, which leak terribly. Again, it's much easier to replace while the motor is out, and exhaust removed.

On all your gaskets, be sure to get the later (Ford designed) Gortex gaskets, rather than the thin paper gaskets that came on the motor in 1985.

Don't forget the tensioner plug on the front time cover. That'll probably crumble when you touch it, so be careful prying it out, lest you cause it to drop into the pan.


Kelnhoffer makes a nice aluminum replacement for this, too.


Everyone else has covered most of the other things.


Make sure you do the fuel hoses and cooling hoses (many in all kinds of places).


If it were me, I'd ditch the air pump. It's a good time to do that, when the engine is out, because you can get at the piping that runs along the side of the block to the rear of the engine. And you can get rid of the air rails (easy to plug; see the Book on how to do it). Way cleaner top of engine when you are done and you will shed pounds in the process.


If your heater valve is acting up, change that, too, while the engine is out (it's on the firewall). These are a bitch to do with the engine in place.


If you have any intention of fitting poly bushes to the steering rack, this is WAY easier to do with the engine out. A really good time to do that. These are cheap (around $20) and make a world of difference in the steering feel and behavior.


And, finally, since you are going to have to pull the radiator to get the engines swapped, clean out all the crap you will find at the bottom of the radiator between it and the evaporator for the A/C. You'll see what I mean when you remove that bad boy.


Given that age of engine, you may want to put a new viscous fan clutch on, too. Not that expensive, and will cross off one possibility if you find you are running hot once the engine is in and running.


I better finish this up before I remember anything else...


-M

Take pics and notes! I have the same dilema on my 89, and am in the process of pulling a 6.0 on a 94 XJ12 to go back in....getting the engine out of this XJ12 has been a challenge, and its still not out.