Check engine light/knock sensors
 

Still sorting through my recently purchased 97XJR. I flew out to get it, and drove it home over 800 miles. On my way home, the check engine light came on. Nothing changed about the way the car was running, and being a car guy, I just came on home. Well, today, I went by my local auto parts store, and they plugged one of the cheap scan tools in. It shows both knock sensors as being bad. Looking for advice, other than the Jag dealer, lol.

Hmmmm. We don't hear of X300 knock sensor problems very often, and certainly not both at once.

I'd begin by making sure they're both pluged in and have non-damaged connectors. They're hard to see and/or reach....you'll need to get the car up in the air.

Has the intake manifold/intercooler been removed at some point? The engine wiring is very awkward to contend with when doing work on that side of the engine and the knock sensors connectors a bit fragile. Ask me how I know.

What were the exact codes?

Cheers
DD

I have never heard of any complaints about the knock sensors in relation to the xjr6. The man to ask would be Andy, after all he actually had a hand in the creation of this system.

My best advice when starting with these vehicles is to buy an inexpensive scan tool, so you can check and clear codes on your own. You don't need a multi-thousand dollar Snap-On item. Less than $100 will get you a very useful tool.

As Doug indicates, it's very unlikely that the knock sensors are bad and VERY likely that someone didn't understand the proper way to remove the wiring pigtail and instead just "gorrilla" pulled em off by force and ruined the connector. The fact that they both returned an error code at the same time, yet there was no change in engine operation, supports the theory that they are both just hanging there unplugged due to the connectors being broken and engine vibration worked em loose. Here is a diagram of where they are located (about equal distance forward and aft of the oil filter). Id' bet good money you find a couple of dangling wires.

https://www.jaguarforums.com/forum/a...ine=1403501306

https://www.jaguarforums.com/forum/d...mAZsTCziYD/9k=

I can't get that link to open, but the previous owner did have the hose replaced that is so crazy, under the supercharger. He said that the supercharger and intake had to come off to change it. Has receipts for it. I am to go out of town in the morning for a week, so at best it will be next weekend before I can get under the car to check it out. I would like to purchase any tool that will help me maintain this car. Suggestions appreciated.

Check this thread for OBDII scanners that are known to read all the potential fault codes on the X300 (Diagnostic Trouble Codes or DTCs). A decent scanner might be your best initial "tool" investment:

https://www.jaguarforums.com/forum/g...oved-**-33347/

Cheers,

Don

Got under the car today...both knock sensors are plugged in. Look undesturbed. However, what I did find, was two vacuum lines unplugged. Both appear to have something to do with the supercharger. They both have a pink(ish) stripe on them. One is far shorter than the other. One is long enough that it was looped around the tie down hook. It has something stuffed in it, I presume to stop vacuum from escaping?? I know just enough about these superchargers to think these aren't vacuum lines at all, as much as they are lines that have to go to a map sensor or something? Could control timing under boost? Ideas appreciated. Its Sunday afternoon about 3:50EST, have the car up on stands if anybody happens to be out there that might know.....Thanks a bunch!!

Your supercharger has three vacuum lines, and they all all connected to the sc adapter plate between the sc and the throttle body.

I really appreciate that. Is there a vacuum diagram anywhere?

Sice I am not familiar with the SC engines, I dont know if this helps-
(Edited to change the pdf to the SC one!)