I had a compression test done on my dying engine (98 XJR) - the results were shocking in the sense that car actually still starts and runs. Cylinders 1 + 4 were zero - 2+ 3 were about 30, and 5-8 were between 30 and 50.

Could this all be from just worn Nikasil cylinder walls? I suppose it's possible, but it seems strange to me that the car was running just fine a few months ago, using only premium 93 octane fuel since. There's hardly any smoke coming from the tailpipes - only a little when started after sitting for a while.

Could this be a timing issue? Blown head gasket(s)? The only codes that come up are random misfire - and the car runs very lean (long term fuel trims between +5 - +20. I'm assuming that some of the techs have seen plenty of Nikasil victims - I just wanted to get someone's opinion before (and if) i dig any deeper. thanks in advance....

 

you can put a little oil in the cyc if comp jumps its the cyc and rings

 

Correct me if I'm wrong, but I think if you called your engine "Le pain chaud de Francais", that wouldroughly translate to "French Toast". Otherwise, it's just toast.

 

Sounds to me like it has jumped time and possibly has a few bent valves.

When was the last time you had the valve covers off and had a look at the tensioners? Have you ever had the tensioners inspected or replaced?

I am thinking more like English toast. Making me hungry for some bangers and hash or whaever they call their breakfast of rashers of bacon, beans, eggsand tomatoe.

That's about the only decent meal the Brits can pull off.

 

I' going to presume your comments were not intended as a shot at me.

Im also going to presume you haven't read the history of this guy and his engine, which has been an ongoing saga.

 

Are you a Brit? If so sorry to offend your cuisine but I am sure many people worldwide would most likely agree with me.

Other than that I know maybe this was the fella I was trying to unload my 01 XJR shortblock onto a few months ago.

 

In the great land of France, I believe they refer to french toast as "pain perdu" , translating to 'lost bread'. either way, the analogy still holds my engine is "lost", or "toast", or maybe just "****"

Oil in the cylinders did not significantly increase compression. I don't know about the tensioners - I haven't had this car very long, and I'm not experienced enough to tell from visual inspection. Based on most of the feedback I've received from this forum in the past few months about this car, looks like it might be time to just hang up my hat. Nearest jag dealer is over 70 miles away - probably not worth the $trouble$. I'm still shocked that it even runs with those compression readings.

In my opinion, England has good sandwiches - fried Mars bars aren't too bad either.

 

Sorry for your luck, you got everything out of it that you could. Well done for that.

 

I had a mechanic peek under the valve covers on the side with zero compression - - it was the tensioners - the timing jumped. Probably bent valves as well. Good call Chasman. At least my 86 sovereign still runs as it should. You can always count on the series III - not so much the early AJ-V8s.

 

Well that sucks.

It sounds as if you were overly preoccupied with the Nikasil slow death syndrome.

Next time maybe check the tensioners.