My 2003 X has almost 76,000 miles on it and the cel and "cruise not available" come on then shut off. They stay on for a couple of days, then goes away and the car runs fine. It seems as though every time I talk about bringing it to the shop it shuts off... Any thoughts?

 

macmar, first, do a good check of all the vacuum hoses for any signs of leaks. After that, odds are, you are suffering from a throttlebody that is starting to go. Stand by. A new throttle body (can't get repair parts, atleast that I can find so far) is going to set you back a little bit ($1600 if bought through Jag, can be had for as little as $800 new at other shops, $400 if you send your current one off and they rebuild it).

I wish the news was better, but a lot of people have been suffering from this very thing.

 

+1 on checking for vacuum leaks first.

 

Thermo.. seeing that makes me want to cry.

 

macmar, this is one of those things that it may be prudent to stop by a mechanic and have him do a quick diagnosis on the car before you go replacing a part like that. I know it may cost you a bit more in the long run, but can also save the aggravation of spending that kind of money just to find out it wasn't the bad part.

 

Was just getting ready to post this same thing. I've seen a lot of posts here and other places where the CEL and "cruise not available" is on. I've also seen the responses of checking the IMT valve O rings, brake booster tube, and PCV valve tube.

My problem is that all those are fine. I can't seem to find a leak on those. Seeing this gives me something else to troubleshoot (although that price wants to send me running).

Something else I wanted to know that maybe you could answer Thermo. There looks to be a diaphragm/check valve on the brake booster tube. Would that give the same results (hesitation, limp home mode, dash lights, etc.) if it went bad? Also, could it be the brake booster itself? One of my symptoms, that I don't see others having is the fact that my brakes are hard as a rock (no assist) when the car is cold.

That being said, if it is the throttle body itself, is there any troubleshooting at home I can do to dtermine if that is the case?

 

Goneguy, the "diaphram" (as you called it) is really a check valve. It is very possible you have a bad check valve and that is not allowing your vacuum assist to work. Contact your local dealership and get a new "Brake booster line". it will cost you like $15 and replace that first to see if that helps anything. That should get your brakes back to 100%.

Now, for diagnosing the throttlebody, don't have any good checks for that. I am looking to get a bad throttle body from some one so I can play with it and see what sort of things I can learn from it and hopefully come up with a cheap fix to restore the throttlebody to 100%. But, so far, no one has stepped forward with a bad throttlebody.

 

Thermo, if that check valve was bad, would that still give me issues mentioned above?

 

Goneguy, the brake issues, definitely. The throttle problems, possibly, but highly unlikely. I would say replace it and then see what happens.

 

Thanks. I'll give it a shot and let you know how it goes.

 

Goneguy, if the check valve on the brake boost hose is white, you will probably feel it deteriorated as it would be the original part. It can cause a vacuum leak and the limp mode symptoms. The replacement has the check valve enclosed in a shrink wrap.

 

Mohrd, yeah it is white. I'm hoping that replacing this part will fix my problem. I still think it is a vacuum leak even if this doesn't solve it. A friend and I tried troubleshooting the leak one night and just could not find it. It was driving me nuts. We seem to hear it under the PCV hose. The hose is air tight. Not sure if it could be coming from that intake boot between the filter and manifold. Wondering if it wouldn't have something to do with the TB as this is where that is located too. Taking it one step at a time.

 

Several have thought that PCV hose was fine only to find a three inch split on the underside. Have you actually taken it off and inspected it? Likely culprit. The new one is sturdier. If it's that big accordion boot, I've heard it isn't sold on it's own only as part of the assembly. But, that was a few years ago. Have a good look at the PCV hose first. You will probably end up doing the PCV, brake boost hose and IMT o-rings anyways.

 

mohrd, I've taken the hose off a few times and looked at it. I've even plugged one end and blew into it (I know, gross, but I'm desperate to find this problem). Based on what I've read, it does seem to be the new hose. It is ribbed and crosshatched. Seems very sturdy. The O-rings I'm going to order when I get the brake booster tube. If those 3 things don't solve my problem, I'm at a loss.

BTW, I wish to thank you guys so far for the help you've given me.

 

Did you check the IMT o-rings? If they're leaking you'll leak a lot more noise...it will be more on the left side of the intake. Leaky o-rings will cause all the symptoms noted. There are lots of posts describing the fix (cheap and easy).

 

Ok, sorry it took so long. I finally got the brake booster tube and IMT O rings replaced. I cleared the codes and started it up. It, at one time, was idleing at about 250-500 RPM and never stalled. It now seems to idle properly at 750 RPM, but if it idles too long, the CEL comes on along with the "Cruise not available." The limp home seems to clear after a couple minutes of driving. So, I guess what I'm saying is, I don't think the problem is solved.

One possibility is that I broke the booster tube where it goes into the intake manifold. I pulled the broken pieces out, but it doesn't seem that the new tube fits in there properly. I see the O ring inside the manifold is still there but the tube seems to wobble around in the opening. Not sure if there was a collar that went there.

 

Yup, there was a collar in there. Push down on the collar and pull up on the hose to disconnect...should have been the first instruction. A wobbly hose won't equal an airtight vacuum connection. Check with Ken @ britishpartsplace to see if he has the collar. I read somewhere, sometime that someone replaced the collar with a brass one from an auto parts store that worked out fine but cannot remember where or when that was.

 

Thanks, mohrd. I'll look into that. Just kinda pissed me off as that $20 part went to $75 as Jaguar decided to change the part number. Same part, same dimensions just different part number and more than 3 times the price. Then, I do something stupid to make it all ineffective. Anyhow, enough ranting. Thanks again for the information.

 

Well, everything has been changed out. Replaced the collar on the new brake booster tube. No change. Still getting the same DTC codes and the CEL is on with Cruise Not Available. The car still hesitates and lurches at stop lights and the brakes are hard as a rock for the first few miles. This is driving me nuts! And, to top things off, the front end is starting to "shimmy". Really beginning to think Jaguar didn't think things through on this car. My Mazda of the same age is doing so much better.