Let me begin by apologizing that my first and only post is to ask for help. You all certainly don't owe me. If you're up to it, please give me some input....
I have a '99 XJ8 with 85k miles.
The chains were original, so I decided to ruin my life by attempting to change them. I bought the tools needed, and got the old chains off without incident. The inside of my engine was remarkably clean! I used new timing tensioners, chains, guides, seals from the (semi)local dealer. Everything seemed to go back on okay.
The first time I bumped the key to start the car, nothing happened. I had forgotten the crank locking tool under the car! I got that out and the sensor back in, and tried again. The first couple rotations of the motor felt/sounded the way any engine normally does, though it didn't start. After about two or three seconds of cranking the engine's tone changed. It began to sound the way an engine does when it has no compression at all. The car never did start.
I pulled the valve covers off, and all four cams lined up with each other. I checked at the flywheel, and the crank seemed to be where it's supposed to be. I tried doing a compression test on cylinder 1, and got about 5psi.
Any idea where I need to look next?
Submitted by asimko@netsolnj.com on Wed, 12/25/2013 - 11:00
Daniel, i a far from an expert on Jaguars (i have enough adventures with my own) but it sounds like you may have broken a woodruff key (or whatever jaguar uses).
anyone who has ever hit a pipe or a large rock with a lawmower knows what i mean.
the key keeps the timing on the gear, since the crank gear can't rotate with respect to the crank shaft.
even if the crank does not turn freely, a broken key will allow the crank or cam to shift enough to throw timing way off (hence the no compression sound)