im still working on getting the coolant issue fixed, so i can post another video of the knock at operating temp

 

Update: I went by the Jag shop today just to see how the kitty was coming along. Darryl said it would be ready probably tomorrow but I had a long lunch so I went by.
He had called yesterday with a prolonged explanation and said I could come by and he would show me exactly what happened. Great guy.

As known, the engine had had the secondary tensioner melt down at some time in its history. Owner had decided not to pay for re-do and shop bought the car off her cheap (we are talking a different shop remember). Guy I bought it from had bought it from that shop. He had the car 2.5 years.

Darryl and I suspected they had maybe put a used engine in with the updated tensioners, guides, etc. We were wrong, but Darryl was right from the start. When he heard the engine idle he said, "At least on cylinder is not firing and there are probably bent valves."

According to Darryl, when the tensioner failed it did relatively minor damage. It is suspected that one of the valves broke off in one of the cylinders and ruined the piston and bent the valves in one or two other cylinders. The shop had elected to just repair the damaged parts in the two cylinders. This would have been OK except they did the repair wrong.

The two of the valves "were not the exactly correct type" according to Darryl and thus caused slight valve touch, especially when cold. Over time this caused the valve to bend giving almost NO compression in those two cylinders. Both on passenger side. He replaced the damaged valves and then shimmed everything to the proper tolerances with just a little extra for leeway.

There is also small vertical score in one of the cylinders but he is indicating to me that it should only lower compression 10-20%. Both he and I discussed this being lower than advised but the only other way is to correct it is with the whole bottom end removal and if THAT was to be done a whole bottom job should be done.

The bill for everything plus him fixing a few other things and bringing all service up to order will be about $ 2,400.

I bought the car for $ 4,200 so the question is if $ 6,600 for this car was a good deal. It is on the high side and would be indicative of a car that was in very fine condition. I will say the car is in much better than above average condition but I don't call things "fine" unless they really are.

Hopefully the car will be ready tomorrow and the next month of "drivership" will give me the answer to the above question of value.

Thanks to all for the advise.

 

Rob, you know it's done, any XJ or this year will be a suspect until you see it's done, even with paperwork! It's now fixed correctly and should give years of cheap service. Enjoy.

 

well finally got around to getting a video of my Engine knock at operating temp

 

That sounds a little different than mine. Ultimately mine was because of valves that had gotten bent (but not replaced) when the secondary tensioner meltdown occurred before I bought the car.

Remember I commented on how I never noted a problem when I test drove the vehicle three times, but that was ONLY because the ******* seller had the car fully warmed up when I arrived. I should have known better and requested a cold crank up.

Anyway, the engine had been selectively repaired but finally the bent valves and pistons clearances ended up causing a slight contact with the pistons when cold.

The tech easily confirmed this by doing a compression test followed by an oil in the cylinder compression test. He pinned it down to the valves and then when the head was removed the problem was obvious.

I am not saying this is your problem but just a suggestion.

I am having a problem with a very bad idle now possibly secondary to a bad VVT which you can read about elsewhere.

 

Safi, that sounds like what I had before I changed my timing chain tensioner. The timing chain was slapping on something. Just my input.