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Richard, Jaguar Technician
Category: Jaguar
Satisfied Customers: 15545
Experience:  12 years at a Ford/Lincoln Mercury and Jaguar dealer as technician and shop foreman.
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I have a 2002 jaguar xtype 2.5 went in for misfirecylinder#5,

Customer Question

I have a 2002 jaguar xtype 2.5 went in for misfirecylinder#5, they tried spark plug and coil, they then said i needed a engine wiring harness and that wasn't it. then they said i needed a NEW ENGINE and now called back and said maybe not a engine but timing chain. my car has 110k miles i get it serviced and take care of it at jag. the engine malfunction light was on and it idle low so thats whi i took it in. does it sound like i need a engine, timing chain? after all the other misdiagnosis will they ever figure out problem.
Submitted: 7 years ago.
Category: Jaguar
Expert:  Richard replied 7 years ago.

Hello and welcome to


FIrst have them do a compression test on the engine. Cylinder 5 is in the back so the intake will need to be removed. If the compression test is good then have them swap out an injector with another cylinder. If the code follows to that other cylinder it's an injector. If the compression is low only on cylinder 5 then you most likely have a burnt valve. If it is low on all cylinders then the timing may have jumped.

Richard and 4 other Jaguar Specialists are ready to help you
Customer: replied 7 years ago.



I went in for echeck in engine light. This is what jaguar performed and my engine idled low. Here is what has been done so by tech. this is what is on my jaguar invoice. cylinder 5 misfires under intake manifold, replaced 3 sparks plugs and ignition coils under intake. vehicle still misfiring after replacing spark plugs and coils. Performed compression test. cylinder leak down test-no leaks. swapped fuel injections from bank to bank,performed exhaust back pressure test. checked ECM inputs/outputs. performed vacuum leak test. checked for blown head gasket. Found engine wiring harness corroded and was replaced. performed cylinder leak test and compression test AGAIN. cylinder leak was 5% and under for all cylinders. compression between 160-165 on all cylinders. performed fuse test numerous times,performed smoke test on engine to verify no vacuum leaks. swapped front 02 sensors from bank 1 to bank 2 to verify.02 sensor operation. swapped mass air sensor. ECM to verify operation. FOUND bank 1running rich and bank 2 running lean indicating that timing is off. What does the problem sound like it could be

Expert:  Richard replied 7 years ago.
Sounds like the timing did in fact jump but which is the cause for the low idle. The dealer should be able to help you out on the repair as it sounds like the enigne harness was replaced when it was not needed.
Richard and 4 other Jaguar Specialists are ready to help you
Customer: replied 7 years ago.
So what are you recommending needs to be fixed at this point.
Customer: replied 7 years ago.
so what are you recommending would be the repair to fix the problem?
Expert:  Richard replied 7 years ago.
I would say that the problem is a timing chain tensioner and the cam tiing jumped. The problem with this is the engine front cover needs to be removed and to do this correctly the engine needs to be lowered out of the vehicle.