Jaguar XJ8



November, 29, 2007 AT 4:05 PM


Car: 2000 Jag XJ8 Vanden Plas

Vehicle Codes:
P0300, P0301, P0303, P0304 (Engine Miss Fire)

Other Code:
P1313 (Catlyst Efficiency)

Compression Test: (LOW Cyl 3)
CYL 4 - 165lb, CYL 1- 165lb, *(CYL 3 -115lb)* Low.

Other Issues:
* Wrong Coolant was placed in the car for about 7 months. Then I had it flushed and filled it up with the correct Orange Colored coolant. But it must not have been flushed correctly b/c it is not Orange right now, it is more of an orange/green color. I am having it reflushed along with the wiring harness repair. The " Engine Cololant Low" light comes on and goes off. Hope the flush fixes it.

* Upper fan wiring harness wires cut by the drive belt. I am having the wires rewired right now. So that issue should be fixed.

* Restricted performance warning light is now on and the car sputters and sounds rough.

If someone could please list some of the Top 5 things that might be wrong that would be great. I really do not want to take it to a dealership and just leave it. I would like to know more from some of the great minds here on this site. I know my descripitions might be more or less vague, but as my name on here suggest.I am a noob : (

Please help me try to understand some of the issues and what might have caused them to happen. I never had any warning for the car about overheating. But then again don't rule it out. I guess it is possible that the car did not warn me of the issue. Not sure.

Thanks for your help. : ) : ) : )


6 Answers



November, 29, 2007 AT 4:14 PM

Low compression on just 1 cylinder? Could be burnt valve or head gasket, get a block test done, tool is about 50.00 snifs gas in antifreeze, to detect gasket problem.



November, 29, 2007 AT 4:57 PM

Thanks for the suggestion. I am getting it tested in the morning when they rewire the harness to the fan & flush the coolant.

Again, I really would like to THANK everyone on this site for their help.

I hope you all have GREAT HOLLIDAYS!



November, 29, 2007 AT 5:58 PM

Thank you you too!



December, 5, 2007 AT 10:55 AM

Hello, the compressions for 1, 4 are ok. But the compression on 3 is a little low. Is this motor a higher milage motor. The codes u have and miss fire codes. Replace the spark plugs and coils for the cylinders. Make sure you get the right side on the engine the miss fires are coming from. The copression should increase when the engine starts running correct. The miss fires also will trigger the p1313 for catalyst efficency. Replace the coils and plugs first changed the oil and then drive car let me know if it helps thanks pat



March, 7, 2008 AT 6:33 PM

I had cylinder #3 coil replaced & changed all of the spark plugs. But the problems seem to still be there.

The knocking sound did not stop.

The check engine light is still on.

The restricted performance light is still on.

If the car gets about 50-55 mph. It sputters and shakes some. I do not drive the car over 35-40 mph. I have only moved it about 3 times in a couple of months. I only drive it for about a mile and park it.

Standing in front of the car looking towards the back of the car. The #3 cylinder is on the left (passenger side) 3rd cylinder back. Right? I had them also try it on the 2nd cylinder back on the same side. But still the issues are there?

Any suggestions or thoughts on.

What the issues could be?
How much money might I be looking at just to find the issues and fix them?

Thanks again for your help. : )



March, 9, 2008 AT 8:25 AM

Did you do the block test yet? What were the results? If you flushed the radiator before this test, you may not get accurate reading!

Please login or register to post a reply.

Engine Cylinder Compression Test - All Cars
Replacing Head Gasket
Serpentine Belt Tensioner Replacement
Code Read Retrieval/Clear Mercedes-Benz C230
Oil Change/Filter Replacement Hyundai Sonata
Oil Change & Filter Replacement Toyota Tacoma