Hello, i hope everyone is well. Here's my problem. I have a 2004 jaguar x type 2.5 litre with a manual transmission. I've owned this car for a couple months now. When I first got it the engine sounded strong but check engine light was on. When I had it checked it checked it showed multiple cylinder misfire, and misfire on cylinder 1, 3, 5, and 6. The engine would run well but occasionally go into limp. Sometimes it would do it at start up and sometimes it would do it after the engine ran for a while. First I ram a can of seafoam through the gas tank and for about a month I didn't have a problem but the check engine light stayed on even though I cleared it multiple times still stating multiple cylinders mis fire. Recently my car appeared to loose all power but would idle fine. When I try to race the motor it sounds like it is under stress. Iv'e clead the mass air flow sensor and checked all vacum lines. I changed the imt seals and the upper and lower intake manifold gaskets. I changed all spark plugs and coils. They appeared to be firing fine but the plugs were gaped to almost .080. I put everything back together and still the exact same problem. I'm wondering if there could be a problem with catalytic converter or the o2 sensor. Please shed some light on my problem. I am at a lost.

 

Stealth, what you are describing sounds more like a vacuum leak than a misfire. Granted, having the plugs gapped to 0.080" is too much and that might be part of your issue. It should be down around 0.054"

I would first start with checking the PCV hose. This is known for splitting on the backside. If you look to the left of the throttlebody, you will see the PCV hose. In the middle of it, there will be a bracket that supports the hose. Right in that area on the backside it will split. This is normally a problem with the smooth hose that was put in at the factory with the earlier cars. Later Jaguar revised this hose and went with a ribbed hose. if you don't have the ribbed hose, it would be wise to get one as it is cheap and will prevent future issues.

The next thing I would do is to have a can of starter fluid and start the engine (leave at idle). Now, find the check valve in the line running between the brake booster and the top of the intake. Spray it and see if the engine RPMs pick up. If they do, you have a bad check valve and that is causing your issue. Next, spray a little bit at the connection on the top of the intake. Again, if the RPMs pick up, you have a leak there.

Lets start here and see what you find. We can then take things from there.

 

Thermo, thanks for the response. I actually checked those locations as in the method that you mentioned. My pcv hos is still the round type but I removed it from the vehicle to inspect it and I don't see a problem there either. I am normally pretty good at trouble shooting but this jag has me stumped.

 

Mode $06 report generated by Torque for Android
================================================

Vehicle VIN:
Vehicle Manufacturer: Jaguar
Vehicle Calibration ID: DE20030797736731

Unit and scaling information are not supplied with the data from the ECU for this type of vehicle. Consulting the manufacturers service book for this information is recommended.

Test report:
------------------
TID:$02 CID:$11
- Lean to Rich sensor threshold voltage(constant)
Min: 0
Test result value: 65,535
PASS
----
TID:$04 CID:$11
- High sensor Voltage for switch time calculation
Min: 0
Test result value: 65,535
PASS
----
TID:$07 CID:$11
- Minimum sensor Voltage for test cycle(calculated)
Min: 328
Test result value: 65,535
PASS
----
TID:$09 CID:$11
- Time between sensor transitions(calculated)
Min: 32,809
Test result value: 65,535
PASS
----
TID:$0a CID:$11
- Sensor period(calculated)
Max: 33,423
Test result value: 65,535
FAIL
----
TID:$0b CID:$11
- EWMA Misfire counts (average) for last 10 drive cycles
Min: 6,554
Test result value: 65,535
PASS
----
TID:$0c CID:$11
- Misfire counts for last/current driving cycles(calculated)
Min: 6,554
Test result value: 65,535
PASS
----
TID:$0d CID:$11
-
Min: 1,638
Test result value: 65,535
PASS
----
TID:$0e CID:$11
-
Min: 1,638
Test result value: 65,535
PASS
----
TID:$0f CID:$11
-
Min: 77
Test result value: 65,535
PASS
----
TID:$10 CID:$11
-
Min: 92
Test result value: 65,535
PASS
----
TID:$11 CID:$11
-
Min: 28
Test result value: 65,535
PASS
----
TID:$12 CID:$11
-
Min: 440
Test result value: 65,535
PASS
----
TID:$1c CID:$11
-
Max: 36,606
Test result value: 16,643
PASS
----
TID:$1d CID:$11
-
Max: 36,606
Test result value: 16,643
PASS
----
TID:$1e CID:$11
-
Min: 28,930
Test result value: 65,535
PASS
----
TID:$1f CID:$11
-
Min: 28,930
Test result value: 65,535
PASS
----
TID:$21 CID:$11
-
Min: 1,180
Test result value: 65,535
PASS
----
TID:$22 CID:$11
-
Max: 2,359
Test result value: 65,535
FAIL
----
TID:$02 CID:$11
- Lean to Rich sensor threshold voltage(constant)
Min: 0
Test result value: 65,535
PASS
----
TID:$04 CID:$11
- High sensor Voltage for switch time calculation
Min: 0
Test result value: 65,535
PASS
----
TID:$07 CID:$11
- Minimum sensor Voltage for test cycle(calculated)
Min: 328
Test result value: 65,535
PASS
----
TID:$09 CID:$11
- Time between sensor transitions(calculated)
Min: 32,809
Test result value: 65,535
PASS
----
TID:$0a CID:$11
- Sensor period(calculated)
Max: 33,423
Test result value: 65,535
FAIL
----


End of report.

 

I had this happen to me. I could not find anything wrong. So I changed all the coils and the car ran great. As soon as I stressed the engine up hill it went into limp mode. so I got a new cat. Problem solved. The cat was ruined from the last guy driving it that the guts of the cat were all in pieces. I got my coils at advanced auto for 45. bucks each. lifetime warranty. Remember to tell them 03 Lincoln ls 3.0. if you order online you can get 20 bucks off every 100. pick up in store. I have used converters for sale if you need them. Let me know

 

Dr. Dome, thanks for the response. In your situation which one of your cats was bad.

 

Same thing happened to my wagon. coil #6 went out. changed them all and the plugs and wires, haven't had the problem since.

 

It was the back one above the transfer case. I was able to pull it from the pass side wheel. Hope for in your case its not that bad.

 

Dr. Dome, I was thinking about taking my car to the shop to have this done even though I normally do all of my own mechanic work. I've heard that you have to drop the sub frame or the transfer case to get the cat out. Did you pull your cat yourself and if so what steps did you use? How did you verify that you cat was bad before you pulled it out.

 

Yes I did it myself. You will need to pull the intake off. Take off the Flex pipe exhaust pipe, and your y pipe. Then loosen your sub frame bolts so it gives you extra clearance. I say it took me about 4 hours. Most of that was trial and error. Its a pricey job if someone has to do it. but it can be done. How I guessed it was the cat was everything else I fixed. I kept getting the p 0431 code, it would always go into limp mode.. But as I stated. Change all the coils first. You may be surprised that you have a few bad ones, Or even oil in the wells causing them to short out. If you want to talk when you are doing the repair I would be happy to walk you through it. Pm me and I will give you my cell.


Good Luck,
The Dr!

 

Dr. Dome, thanks for the information. I think I will try and work on it this weekend. If I have any issues, I will let you know. Thanks for all the help.