Please help. I am new to the forum and to the Jaguar community. I just bought my 2002 X-Type 2.5l. The car was driving just fine for a day after I bought it and now the car wont go over 3,000 rpm even if I floor the gas and go wide open throttle. This also happens in neutral too. I heard someone say Restricted Performance & failsafe 3000rpm but not sure what and how to fix that. I had a muffler shop read the codes and it mentions running too lean. I thought it was the catalytic converters but its restricted to going passed 3000 RPM so Im not convinced its that anymore. Please help.

 

Update.. I called Jaguar of Houston and the guy said it's my Mass Air Flow sensor. The codes it threw out were bank 1 and bank 2 running too lean. I am going to buy it and pray this works. I will keep yall updated but if yall had this problem please post just in case it doesnt work.

 

There is probably a vacuum leak. Withe the motor running open the hood and listen for any hissing. Common leak areas are the PVC hose ( just above the air filter next to the throttle) or the IMT seals on the back left corner of the intake manifold, the brake booster vacuum check valve.

The vacuum leaks are way more common then a mass meter on an xtype.

 

It is likely a vacuum leak, but I had the same codes a while back and I did have to replace the MAF sensor. That fixed the issue with my car. Hope that helps give you some hope with your car. Best of luck.

 

Wait! Were the codes P0171 and P0174? Check vacuum leaks first. I'm not sure how you can call the service department and have them diagnose your problem over the phone. Please check the big three "leakers" first. Could very well be the MAF but...likely a vacuum leak between the MAF sensor and the intake.

PS did you take it over 3000 rpms on the test drive?

 

Thanks for all the replies. I did take it over 3000 rpms on the test drive and the weird thing for the 1st 2 days it didnt have any of these issues. I replaced the Mass Air Flow sensor and that didnt fix the issue so I put the old one back in and returning the new one. I will be checking the leaks later today. I will keep yall posted.

 

I called all the auto parts stores and none of them know what an IMT seal is. Anyone know another word for the seal and can it be bought anywhere other then the dealership?

 

I'm pretty sure this is a Jaguar dealership purchase only. But, they are inexpensive at about $3-$5/o-ring. If you don't live near a dealer, I think snail mail is your only other option.

 

Thanks I went to dealership and I got the o rings. I am going to install them tonight or tomorrow morning. I will keep yall posted on if this fixes my issue or not. Anything that I need to know on the install? Seems really easy and parts guy told me that I just put them on and nothing else. Just wanted to make sure.

 

They are easy. The only thing that may be of concern is the lower black valve. When you take off the two bolts you'll notice that (unlike the top valve) this lower valve will not have enough clearance to come completely out. What you have to do is cut the old o-ring off (should be yellow in color) and then gently put the new (green in color) o-ring on over the valve. The o-ring will give a little to allow you to do this, just be gentle and you'll be good to go. There have been many members of this forum, myself included, who have done it this way.

Takes all of 5-7 minutes depending on your beer intake. Good luck!

 

SAME problem of mine , but i also have jerking at 3000 rpm and engine popping sound , replaced plugs and coils , cleaned injectors , reprogrammed computer , no vaccum leak ,
now sound disspears fast after ignition and only when car is cold , hesitation is solved partially by revving very slowly till i go past 3000 , then it would run like a JAG .

 

Ok so I replaced the IMT seals and I was able to get the lower one out with a lil pull. I turned car on and it started to work normal for a couple miles and then the issue starting happening again and the no cruise control came back on. I will try the PCV hose and the booster. If this doesnt work what should be my next step? But I must say that I no longer hear a leak from the back of the intake.

 

I bought the revised PCV hose and this did not fix the problem. I will try to unplug battery to reset ECU. I also checked the booster vacuum and no leaks. If this doesnt work any suggestions or should I just take to the Jaguar dealership.

 

Sounds like it's just a matter of how much you want to keep troubleshooting the problem. I would have taken her to the dealer by now, as I'm not that patient of a person. Sorry I don't have any other suggestions, perhaps someone else on here can help out.

 

How many miles is on your car? does it have a k&n air filter? What kind of gas are you putting in.? Do you have a fuel pressure gauge to see what it is.

 

128,000 miles, regular filter but will be upgrading after I fix this issue. I am putting regular 87 octane and I dont have a pressure gauge. Car is running normal yesterday and today so far but still throwing codes. I will scan it again today and see if its different codes now. After I put in the PCV hose it wasnt working and like I said all of a sudden it started to drive normal. I will keep yall posted.

 

PAJ- Someone mentioned earlier in the thread the brake booster cable. I had the same codes on a X-Type with 193k miles with similar symptoms, although I was looking at the speedometer and it chokes a bit at 35mph but if will go after gentle excelleration. I didn't touch the MAF sensor but replaced the o-rings and PVC hose and the brake booster and the codes went away. When those codes were gone I now have code 0420 which is a CAT issue. Try replacing the Brake Booster and when you go to the dealership you'll want to ask for the plastic connector that holds the break booster in place on top of the manifold intake.

 

The brake booster looks perfect and dont hear any leaks. I did take it to get the codes and it still says bank 1 and bank 2 running lean. I noticed the car states it needs Premium fuel only. On my next tank I will try Premium fuel. Also the codes are saying the o2 sensors are bad from what the lady at Advance Auto Parts told me. The issue came back I guess I jinxed it. So its looking like its either brake booster which I doubt since it looks new and or o2 sensors.

 

These fixes are fairly inexpensive compared to what you would pay at a shop. I never found a leak but codes did clear after replacing the parts. It was suggested to me to put new o2 sensors on, which I did. The top one is a little work and the bottom one is much easier. They were 130.00 for the pair for the Denso brand at RockAuto.com.

Good luck.

 

PAJ, did the code P0420 go away after you replaced both O2 sensors? I'm having a similar issue but in Bank 2 (P0430).