Got an oil burning issue, at 250k miles, so I think it would be good to replace the valve stem seals. I've checked inside the cylinders with a borescope and can see oil dripping down from above. When I added a bottle of rubber seal reconditioner, the problem goes away for a while but then comes back.

What concerns me most is when putting the camshafts back in after having turned the engine multiple times to compress the rope in each cylinder.

How do you get the timing correct such that pistons & valves don't give each other the kiss of death?!

Chris

 

You will have to get the camshaft alignment tool kit, like this one: https://www.ebay.com/itm/Engine-Cams...EAAOSwKtxc1jML

 

I actually already have this tool in advance of any tensioner replacement.
If the crank is aligned and locked with the tool, how should the camshafts sit?

 

With the crankshaft locked, install the camshafts with their flats (located near the front cam bearings) facing up, more or less, in relation to the head plane. Then clamp the alignment bars over the flats which will bring them to the correct position. Then, tighten the bolts securing the sprockets to the camshafts. You should download the Jag Service Manual which explains the procedure in detail.

 

Many thanks for this. I'm sure I knew how to do this on paper last year but somehow forget the whole lot a few months later!

I've got the manual on pdf but somehow got confused with multiple other similar procedures that seemed to skim over the most important bit. I'll get my thinking cap straightened up and find it in there too.

 

Just a thought..... when I did a valve job on my 98’ XJR when it had 234K miles, I gained considerable HP. I think it would be very beneficial and would give you piece of mind and you wouldn’t have to do that much more labor if you pulled the heads off the engine. Getting the heads surfaced, valves and seats ground down, new valve stem seals and most importantly getting the valve clearance adjusted.

 

Hi Chris, did you ever do this job, I'm considering it for my XK8.