Jaguar doing Jaguary stuff

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?

I'd start by making sure Cylinder 1 is at TDC when you're lining everything up.

Well, if you have basically no compression in #1 it sounds like at least one of the valves is not closing. Are the cams rotating properly? Are the chains fully engaged and tensioned properly?

That's about all I can contribute, though it might be helpful to check compression on some other cylinders to see if you've got an issue there.

Worst case is that you got the timing wrong somehow and you've bent some valves in the process.

Dang man, that sucks. After reassembling a motor like that it's best to rotate the engine by hand (well, using a socket on the crank bolt and ratchet with a small cheater pipe) prior to trying the starter. That way you can feel the interference before applying the kind of power and speed that the starter will apply and if there is interference you won't bend valves.

Apparently you didn't do that since forgetting the crank holding tool is kind of hard when you're trying to turn the engine over by hand. Where to go from here is as Basil and Swank suggest. Hopefully you didn't bend valves. Good luck!

compression test or leakdown test? If you are getting any compression, there is a good chance that the valves are ok, just that time is off.

And yes. always hand crank an engine after the time gear has been altered at all, it's the only way to tell that everything is missing everything else.

The million dollar question is: Why did you change the chains at 85 thousand miles? That is Timing belt interval.. chains should go longer

I remember some Jags having problems with chains and guides. Probably that's why.

The chain tensioners are plastic (not just the guides, the actual tensioner housing!) from the factory, and they fall apart. Im a car dealer, & i wanted to sell this car with the updated metal parts.

ah, ok. That makes more sense. Any luck with getting it started?

I hate to say this, but I kinda think cranking it with the tool locking the crank gear in place actually sheared the key for the crank pulley. I would NOT try to start it any more until you verify the timing is correct and the key is in place.

I'm with Curmudgeon, check your crank key.

I had one of my secondary timing chains snap on my 01 Lincoln LS (same engine as the Jag).

The engine made a terrible noise and cylinder # 8 had zero compression. I figured the worst and didn't follow through with any further diagnostics.

I eventually got around to doing an autopsy on the engine... after cutting the car up.

Sure enough, the exhaust valves on #8 were bent ever so slightly and only needed two valves. The piston only had a slight nick. The engine was repairable...DOH!.

Hopefully you will have better luck.

This is the disastrous outcome of my Pimp'n Lincoln. https://www.youtube.com/watch?v=C7YoaqeMoic

Where does the crank locking tool engage? Sounds like it installs where the crank sensor goes (I'm guessing flywheel) and if so I don't see how the crank would see any forces, as both the starter and crank locking tool would be on the flywheel/flexplate.

I am very sorry to hear that. There is nothing worse than attempting to do some maintenance work to prevent future trouble and in the process doing some damage and creating a problem. We have all been there and done that at some time or another. Hopefully, yours is something simple and easily fixed. I feel your pain.

There is nothing worse than attempting to do some maintenance work to prevent future trouble and in the process doing some damage and creating a problem

Years ago when they were worth fixing and less of them had been scrapped out, you used to see a lot of dohc 3000gt/stealths on CL with bent valves due to an attempted preventative timing belt replacement.

fujioko wrote: I'm with Curmudgeon, check your crank key. I had one of my secondary timing chains snap on my 01 Lincoln LS (same engine as the Jag). The engine made a terrible noise and cylinder # 8 had zero compression. I figured the worst and didn't follow through with any further diagnostics. I eventually got around to doing an autopsy on the engine... after cutting the car up. Sure enough, the exhaust valves on #8 were bent ever so slightly and only needed two valves. The piston only had a slight nick. The engine was repairable...DOH!. Hopefully you will have better luck. This is the disastrous outcome of my Pimp'n Lincoln. https://www.youtube.com/watch?v=C7YoaqeMoic

That is really something. Out of curiosity, did you get more for it in parts than you would have for a running car?

In reply to Basil Exposition:

So far the Lincoln massacre has grossed $944.00 and I still have a ton of parts in my basement. The parts are slow selling and tend to sell for less than expected.

I made a spreadsheet to help estimate what to expect and I figured around $4K in parts

The car was worth $2500-3800 with a good engine and around $700-$1200 with a bad engine.

I think when this is over I'll will have realistically grossed around $1500-1800.

My only though would be to make 100% sure that the timing is exactly where it is supposed to be, it could have been one tooth off and looked fine but ended up far enough off after cranking it a few times to bend the valves. Its very important to turn the engine over 2 or 3 times by hand after work like that.