I have a 2002 X-type 2.5 , Last week I started my car in the garage and unexpectedly had no power assist for the brakes and almost went through my fence while backing out. At first the car ran very rough and if I revved the engine the power assist came back but didn't stay until 15 minutes or so passed. Once the car warms it seems to stay all day , I pulled the vacuum pipe off the manifold that goes to the booster and when the car is first started in the morning the vacuum pull starts off very weak. Like I said if I rev the engine the vacuum gets stronger and once it's warm it's fine. Does anyone have a clue what might be causing this? Also several times it says Cruise not available while this is going on. I'd like to try to resolve this myself without having to take it into Jaguar. Any assistance would be greatly appreciated.

 

Welcome aboard. I've moved your post to the X type section where you will get better help.
Please try to find time to visit the New Member's section for an intro.

 

Rccrazybill, My guess is that you have a leak in your vacuum system somewhere. I am also just going to take a shot in the dark and say that your check engine light is on and throwing the P0171 and P0174 codes. These codes make cruise not available and are because of a vacuum leak. The top three culprits of vacuum leaks are listed:

1: The valve on the brake booster hose (looks like a little grey plastic piece on the hose leading to the manifold.) I coated mine in epoxy and everything was fine.
2: IMT o-ring's. These tend to fail prematurely and cause a vacuum leak as well. These are located where the two black circle caps contact the intake manifold.
3: The PCV valve hose. This is no longer a problem with the newer xtypes (04 and above) but for 02-03, Jaguar used a PCV valve hose that would crack and collapse in on itself.

You can buy everything on that list for either free (#1) or $20 off of ebay (#2-#3.) If your check engine light is on, you should the codes read because CEL's tell you ALOT about what is going wrong with the vehicle.

 

I found the vacuum leak but the check engine light is still on , can I reset the computer myself or do I need Jaguar to do it?

 

It might 'put itself' right - otherwise buy a cheap OBD reader (you need one with a Jag) and reset it yourself.

 

Thanks for the info , it saved me a lot of money and everything fine now

 

Glad the forums could help you out!