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I am having trouble with my XJR. When driving like an old lady the car runs fine seems to go through all the gears ok. As soon as you hit the gas the transmission kicks out to neutral. I don't know if it is a transmission problem or something else. Anyone else have this problem before?
I have moved your post from the forum for the X308 to the forum for the X350, which is the Jaguar factory project code for your 2004 XJR.
When the transmission kicks out to neutral, does the gear selector lever move to the N position on the J-gate, or does it stay in the Drive position?
Have you tested the transmission behavior with the gear selector lever on the left side of the J-gate in positions 5, 4 or 3?
One possibility that comes to mind is that some owners have reported that the bolts or screws that secure the gear selector cable to the side of the transmission were loose or missing, so that would be one thing worth checking.
Any error codes? There is sensors monitoring input and output shaft speeds and if there are not as expected, there would be error codes.
torque convertor, fluid level, coils over plugs?...
I had this happen a few times a while back when trying to pass cars on the highway. Would only happen once in a blue moon but nerve racking nonetheless. This may sound funny but I suspected 1 or more ignition coils tobe on the way out.
I previously had coil failure to cause my transmission to misbehave a year ago. I replaced the fluid pan to no avail. I was worried that I would need a new transmission or a new car. I luckily discovered that this car is horrible at detecting misfires. It finally gave me a misfire code after a week of horrible behavior.
Anyways I started to experience your symptoms a few months ago and went ahead and replaced all the coils this time. No slip since. Knock on wood.
I do have a couple of error codes but I do not think they relate to the transmission problems I am having. P0101 P0442 P0456 and P1000. The first time I had trouble the transmission slipping I had gunned the engine and when the transmission went back in I got a transmission fault - reduced performance - and cruise not available verbiage in the display in front of the steering wheel. Then the car would not downshift - I ran it for a few miles and was then able to turn it off. When I turned it back on everything seemed pretty normal. I took it a couple of days later and had the fluid checked it was about 1 quart low. I did get a code when I had the transmission fault P1643 but after turning the car on and off a couple of times the code disappeared. I have talked to a couple of guys that work on Jaguars and they both think the transmission needs replaced.
I do have a couple of error codes but I do not think they relate to the transmission problems I am having. P0101 P0442 P0456 and P1000.
P0101 indicates a problem with the Mass Air Flow Sensor (MAFS) circuit or sensor performance. The Engine Control Module (ECM) relies on the MAFS signal to determine engine load and torque, which is critical to orchestrating smooth gear shifts with the Transmission Control Module (TCM), so this could be a contributor to your problems. P0101 also causes the maximum engine speed to be reduced (Restricted Performance).
P0442 and P0456 indicate a leak somewhere in the evaporative emissions system (EVAP), and results in adaptive fueling being inhibited. The most common cause is the fuel filler cap not being properly fitted.
P1643 indicates a network communications (CAN) problem between the ECM and TCM. The maximum engine speed is reduced (Restricted Performance), and the maximum throttle opening is limited to 30%.
P1000 is just a readiness monitor that means the the system check has not completed since the memory was last cleared.
You can see all the Diagnostic Trouble Code (DTC) definitions and many possible causes of each code in the DTC Summaries manual:
I would ignore the p1643 code for now. I got the same code the first time I got a misfire code that was causing my transmission to act funny. The transmission relies on engine feedback to operate properly and can get confused if it doesn't receive proper feedback and fake codes can be thrown. I belive if you sort the other codes first you'll be fine. At least I hope so.
I have good news. Car is fixed.
I took my car down to my mechanic this morning. He was going to put in new plugs and check the coils. I was really beginning to doubt if I was going to make it down there, transmission was really giving me a hard time. I was using the gear shift - starting in 2nd etc. even in 2nd it was slipping in and out.
Turns out the plugs did need replaced he said one was really bad. After he put in the new plugs he determined that I had a bad coil #7. Put in the new coil and the car so far runs great. No more slips for the transmission.
A big thank you to BlackKat for your post. Your post gave me hope. I had taken the car to another mechanic and after I described the slipping of the transmission he just said sounds like you need a new transmission. He was supposed to be an Foreign car expert. Called me back saying Jaguar wanted $14,000 for a transmission but that he had a better deal from one of his suppliers for $6,000.
Thanks for the help guys.
Jim
Is there a way to test the coils? I'm having some trouble with my car as well. I took it to a transmission shop and they said the transmission was fine. I'm thinking it might be the coils but at this point I don't have any codes to confirm it.
What JagV8 is referring to is a COP (Coil-On-Plug) tester. They come in a variety of designs from simple ones that you plug into the spark plug end of the coil and watch for spark (easy enough to do with a spark plug and a test lead or jumper cable to connect the plug threads to ground), to more expensive inductive testers with which you lay a sensor probe on top of the coil in situ and it tells you if the coil is firing. Do a google search for COP tester and you'll see what he is talking about.
First off, thank you for your very prompt responses. As a follow up, it seems like those testers will mainly tell you if the coil is bad altogether. It seems like I'm getting a misfire mainly when the engine is under a heavy load. If I take off from a standstill it's fine, once I get up to 45 MPH + and hit an incline it won't shift out of top gear and possibly the TCL isn't disengaging, sometimes the engine runs rough along with it. If I manually downshift it's fine. I'm kind of thinking there's a coil with a crack in it that's leaking spark. Maybe I could pull them and check them.
First off, thank you for your very prompt responses. As a follow up, it seems like those testers will mainly tell you if the coil is bad altogether. It seems like I'm getting a misfire mainly when the engine is under a heavy load. If I take off from a standstill it's fine, once I get up to 45 MPH + and hit an incline it won't shift out of top gear and possibly the TCL isn't disengaging, sometimes the engine runs rough along with it. If I manually downshift it's fine. I'm kind of thinking there's a coil with a crack in it that's leaking spark. Maybe I could pull them and check them.
If there is just one COP thats bad you could just buy one new COP and then replace one at a time to see if there is any difference. Somewhat of a chore but less expensive than buying all new.
Question for anyone: will an intermittently bad COP throw a DTC?
Question for anyone: will an intermittently bad COP throw a DTC?
The DTC Summaries manual doesn't expressly state so, but I think the answer is yes, if a random misfire is detected P0300 will be flagged. If the misfire is severe enough, it will also trigger one or more cylinder-specific codes (P0301-P0308) and P1316 (misfire causing excess emission) and possibly P1313 and P1314 (possible catalyst damage). Here's the language from the DTC Summaries manual:
If there is just one COP thats bad you could just buy one new COP and then replace one at a time to see if there is any difference. Somewhat of a chore but less expensive than buying all new.
An excellent suggestion, jackra_1. Especially given how inexpensive coils are. The coils Jaguar is currently supplying are the Airtex-Wells / FordMotorCompany 5C1420, which are over $100 each from a Jaguar dealer but only $31.79 each at RockAuto. I've replaced three of our coils so far and keep two spares in the trunk.
The what I was thinking of doing and now that see it's "Don Approved" I'm definitely going to try it. Actually, if I knew for a fact it was a crummy coil I'd probably just go for the whole set, we'll see.
01-30-2017 | 08:56 PM
2004 Jaguar XJR Transmission
