I bought a great 89 xjs 5.3 this summer. The engine is frozen
due to a dropped valve seat. I found a good replacement and have the
old engine out. I am replacing all seals and gaskets, hoses, belts,
and tune up parts. I may get a rebuilt starter too.
My question to the group. If you had your engine out and could get
to every thing. What things would be important to address now.
I’m worried I’ll regret some small but vital task, and pay later.
This job the most challenging car ordeal I’ve ever encountered. I
consider myself a motorhead, and was humbled by this project. (Read…
Trans mount and exhaust cats removal…yike
Gee, how much work do you wanna do?
You might want to check to see if the engine you have was assembled
with gortex gaskets or paper gaskets. If paper, there are a couple
I’d suggest replacing a few of them now while the engine is out. The
sandwich plate gasket tops the list, because it tends to be leaky and
it’s nearly impossible to do with the engine in the car. While
there, you can replace the oil pan gasket as well, and clean and seal
the threads on all the sandwich plate bolts that have heads inside
the crankcase per a TSB to prevent oil leaks along the threads. And,
as long as the sandwich plate is off, you should replace the O-rings
at every fitting in the oil system piping with Viton O-rings.
Also while the sandwich plate is off, remove the rear main bearing
cap, apply Loctite 518 sealant to the mating surface, and bolt it
back up. After reinstalling, you’ll need to inject sealant (not
518, this needs to be something that fills a space, I used a copper-
based substance) into grooves along both sides of that bearing cap.
You might opt to replace the rope seal itself while there using the
Ford 460 graphite-impregnated seal and a Sneaky Pete, although
frankly I doubt if this is really necessary.
You might want to pull off the timing chain cover for the same
reason, replacing all paper gaskets with gortex. Easiest done with
engine out and sandwich plate off. Of course, while you’re in there
you might want to replace the tensioner, either with a new one or
with the redesigned version available here. You may want to replace
the timing chain tensioner access hole plug with an aluminum plug.
And you may want to replace the front oil seal.
You probably also should pull off the filter head assembly, make sure
it’s flat (have it milled if necessary, or just carefully file it
with a flat file) and reinstall with a gortex gasket. There’s a
blank-off plug on the back side of that head assembly that should be
unscrewed, the washer replaced, and reinstalled. The little hoses on
the question-mark-shaped tube from the filter head to the crankcase
should be replaced while they’re so easy to get to.
I dunno what all is presently bolted to the engine, but I’d suggest
removing the exhaust manifolds and reinstalling them with the latest
design gaskets (which have a little metal ring around the exhaust
passage), making sure to use anti-seize compound on the nuts when
reinstalling. You might want to remove the honeycomb flow
straighteners in the downpipes.
There are other things you could do, including pulling the intake
manifolds and cam covers and resealing a bunch of stuff there as
well, but IMHO the top end stuff isn’t significantly easier with the
engine out than with the engine in, so there’s no serious need to do
I’m sure others will chime in with things I’ve forgotten.
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