So some folks may recall that I just purchased yet another X300 car, a 1995 XJ6 VdP that the previous owner claimed had a broken lower timing chain. In fact the guy I had I bought the car from had the engine partially disassembled. The previous owner had taken out the radiator, AC condenser, and most stuff off of the front of the motor in preparation for removing the lower timing cover. He had told me this was because the lower timing chain was broken. He said he confirmed this by spinning the engine over with the cam cover removed and said the cams did not move with the crank. So once I got the car back to my shop, I set about finishing the job of removing the lower timing cover. All that was left to do was the AC compressor bracket and the water pump. Once I got those off I discovered one of the lower timing cover bolts had broken off in the cover due to corrosion and I had to drill down through the shank of the bolt to get it freed up.
Once I got the timing cover off, I expected to find an obvious problem with the lower chain. So I was very surprised to find NOTHING unusual with the lower chain. This was yesterday afternoon and at that point I had to leave the shop. I did not get back there until today. I immediately put the crank damper back onto the front snout of the crank and proceeded to turn the crank bolt with a large breaker bar. I immediately discovered that it was necessary to replace the upper timing chain tensioner so the upper chain would properly mess with the intermediate gear, Once I did that everything spun over fine with the breaker bar.
I really do NOT understand why the previous owner would go to all of the work of disassembling the whole front of the motor after having convinced himself that the lower chain was somehow broke and then when I finally finish disassembling the engine, I do not find a single thing wrong. This all makes no sense to me at all.