Diesel Misfires

A loss of compresion in one or more cylinders? Is the head gasket still serviceable? Is there unwanted oil in the cooling water circuit?

I've just had a look and there seems to be no oil in the cooling or anything untoward with the oil.

A partially-blocked injector? Is the fuel filter in good order?

I don't know about the fuel filter. It does seem to be getting slightly worse over the last few days.

at full load engine is working fine and while idling its missfire.................................................... straight way look at fuel system (injector as well fuel pump)

If it runs fine under load, but seems to miss while cruising one would tend to believe that everything mechanical is working fine, but then one or more of the electronic functions or controls is the issue. I am the Jaguar Car Clubs of Arizona technical expert. We don't get the diesel here so I cannot claim too much experience, but I am an automotive engineer so here goes nothing! Are you getting an check engine lights on the dash, and what specification (country) is your car built for? In today's world of electronic controls trying to keep everything clean running and economical I have to believe that your on board diagnostic system should be going crazy with a missing cylinder going on! A quick scam of the OBD system would be something worth having before you start charging around like a bull in a china shop! Here is my personal Email if you would like to communicate further. johnd7618@cox.net

It can be a partially plugged fuel injector, sticking or burned valve, faulty injector pump , faulty injection check valve. excessive carbon deposits in the pre-chamber.

I just took a quick tip toe through the Jaguar forum at www.jaguarforums.com based inthe UK and it seems that 2.0 l Jag diesels had some electrical issues from injectors to pumps and a few others. As "guest" mentioned the big recommendation is to put a scan tool on it and see if it is tossing a few error codes.

My suggestion would be to ask the British mechanics that are monitoring the forum for more precise information on what the cause may be and then act on the information. They are a bit more up-to-date those specific issues than those of us in North America.

Is there a water trap in the filter (or seperate), does it need the water removing? If yes, do it!

This is similar to an experience I had some years ago.....

One of the reasons for this type of problem is running with the tank almost always empty and only partially filling it, never full.

On older type of steel tanks, doing this also promotes rust, not a problem today as most tanks are plastic.

Diesels don't misfire they cough.

Coughing indicates a code error is being prompted.

Most likely the wiring harness has experienced wear during the 115,000 trip and stray energy is precipitating the coughing that wouldn't be noticed when under load.

A code reader will indicate the area a problem may be occurring only, I'd put money on a wiring harness issue being the root of it.