My 99 XJ8 will occasionally go into "restricted performance" for a couple of seconds then the light will go out. It happens most at a steady speed usually between 25-45 MPH.

No strange noises and the timing chains/tensioners were done 5000 miles ago.

I pulled the code and got a P0333 which is Bank 2 Knock Sensor High. My question is it common for these things actually go bad?

 

The answer to whether knock sensors can fail intermittently is yes.

After "Restricted Performance" blinked at me a few times and I got a CEL a couple of times, I decided to just spend the $111.00 on a new sensor. So far the problem is solved.

 

As was stated, yes they can read out of line then return to normal. First things I would do is run some injector cleaner through the system, think about when the plugs were done last and if over 30k or so pull one on that side to see what it looks like then clean the electrical connector for the crank sender followed by a spirited drive to let the injector cleaner start to work and clean out any build up you can. If that fails spend the $110

 

I'm not quite sure how any of that has to do with a P0333 code that's telling the tech a knock sensor is reading high.

Please help me to understand the logic of how fuel injector cleaner, cleaning the crank angle sensor, and replacing spark plugs 70,000 miles before they are due can even remotely affect the knock sensors and trigger a P0333 or P0332 code.

Maybe..... it's the Maaco paint on my car that was causing the problem. The new sensor must get along with it much better than the old one did.

 

Sinister,

Sometimes the answers you get to your questions do not make sense, are flat wrong or unclear. In all cases, one must assume, they come from guys trying to help.
The point is, don't get peeved if responses are not up to your expectations. Sarcasm certainly has it's place here but not if it's driving respondents off the air.

 

It is related because carbon buildup/clogged injectors are contributing factors for spark knock (detonation) which knock sensors detect. The injector cleaner could "repair" a lean condition from clogged injectors.

Yes the knock sensors can fail intermittently. My jag was doing that when I bought it. If you search you can find my thread where I post the part number for the knock sensor on rockauto.com for $35. Its "for" a 99 XK, but it has a little extra wire, IIRC. It bolts right in place of the stock one.

Here is the link to my thread:
https://www.jaguarforums.com/forum/s...ad.php?t=33382

The last 2 posts have the part number and description of the part!

PN for the lazy: 5s5619

 

Man I wish I would have found your post (to save $75.00) back when I did my searches for "knock sensor" here. Either it did not come up or I overlooked it. The link and the pn you put up should help future searchers. Hopefully I can remember this if/when the other one has problems.

Thanks,

Ken

 

Tarhealcracker,

I have no deliberate intention to drive respondents off the air. However I do believe that when information is way out there, it needs to be called out otherwise a novice might take the info as fact.

In the case of this thread, I posted the problem and followed up with an answer to my own question so that someone searching in the future could have the answer. The subsequent post by benebob was an add on that could confuse other readers and I wanted to clear it up.

The comment on Maaco paint is a result of him busting my ***** (without any real facts) on a previous thread of mine. Normally I don't have a problem with sarcasm but I couldn't resist this time.

Ken

 

My 1998 XJ8 4.0 has the same problem as Sinister1 described.
(Occasionally "restricted performance" (+ amber light) for a few seconds, mostly at a lower steady speeds and when driven very calm.)

No strange noises, no loss of power, no vibrations, no anything.

I had it in the shop (Jaguar specialist) last week.
They drove it around for 5 days and about 120 Miles to "test" it and finally came up with nothing.
They even told me that there is no fault code in the computer.

I bought a simple and cheap OBDII reader (CReader V) and hooked it up yesterday.
Two fault codes appeared immediately !!!
-1- P1111 - Which I read is quite normal to show up (my MAF-Sensor is new!)
-2- P0328 - Which indicates a faulty knock sensor on bank 1

Strange that with my cheap OBD-reader I got fault codes and the so called specialist didn't get one.

Anyway- I don't want to spend big $$ (or Euro actually) for a new sensor to find out in the end that the old one was working.
So I decided just to interchange the 2 knock sensors (they are identical) and keep an eye on the OBD fault codes.
If the knock sensor was the troublemaker the next fault code I should get would be one of those:

P0330 Knock Sensor 2 Circuit Malfunction (Bank 2)
P0331 Knock Sensor 2 Circuit Range/Performance (Bank 2)
P0332 Knock Sensor 2 Circuit Low Input (Bank 2)
P0333 Knock Sensor 2 Circuit High Input (Bank 2)
P0334 Knock Sensor 2 Circuit Intermittent (Bank 2)


To change the knock sensors is not very challenging (I have the screw-on types) and took about 30 minutes of fiddling on top of the engine.

So far (after a short test-drive) everything is fine and I got no codes (except the P1111 which even shows of immediately after clearing the codes and without firing the engine up).

Maybe I was lucky and the fault was just caused by a bad connection (I sprayed WD40 on/in all the connectors I found).


Regards,


David

 

Good Idea swapping the position! That will certainly let you know who the culprit is.

The key here is that you first have listened for signs of detonation and knew that your issue is at light throttle where the engine is not "pulling the load" so detonation is not likely in the first place. Therefore it seems the sensor was most likely to be the guilty party.

Looks like you may have gotten lucky with the WD cleaning the contacts and solving the problem. I was not as lucky. Cleaning the contacts was the first thing I did and it didn't help my situation.

Ken

 

Ok kids......easy now.

The knock sensors can most definitely be intermittent. They are piezo electric [crystal] devices that are very susceptible to several things. They are easily fractured if dropped, over-torqued or struck. They are also easily destroyed by spray cleaning a hot engine. Cold water on a hot sensor will do them in every time; I've replaced dozens over the years following an engine cleaning. Always let the engine cool first.

Sometimes if they get flaky, removing them and cleaning the surfaces and properly re-tightening them will stop the faults from flagging. Switching them side to side doesn't hurt, either.

Treat 'em with respect!
OOPS! Almost forgot....
Torque = 20Nm or 14 lb/ft

 

That was exactly what I did.
After a longer test-ride this afternoon I'm pretty sure that my problem is solved.
No more "Restricted Performance" message, no more amber warning-light in the cluster.

Thanks for all the input here!
Great forum BTW...


David

 

Okay, I guess I "hoorayed" a little bit too early.

Today the RP + amber light came up again.
Plugged the OBD-reader in and guess what - P0333 (Knock Sensor Bank 2 High Input).

Based on that I assume that I finally identified a bad Sensor.

Now I just have to find a spare part for a reasonable price...
(Wish I could order that 35$ Rockauto part, but I guess that it will be more close to 150$ over here.)

David


*update*

I exchanged the knock sensor on Bank2 with a used one I got off eBay UK for cheap and everything is fine now.
(No amber light, no messages since a week now.)

 

I normally post on the S type area but I ran across this post while doing a search on knock sensors. I have to agree with Ken on the issue of questioning/challenging incorrect information. In this case the response about carbon build up was indeed way off the mark, and the follow up explanation equally bad. If a knock sensor is simply doing it's 'job' ie detecting knock, it will not throw a code.

 

This is true! I must have had my head up my *** when I posted that, but carbon buildup is a contributing factor to spark knock. A code would only be set when something electronically went wrong with the sensor. Forgive me for putting out any misinformation

 

I am having knock sensor problems. How difficult to install and where are they?

 

What makes you think you have a knock sensor problem?

 

Gus, symtoms are: after restarting a warm car and drive about a mile I hear a slight thud, the car stalls and the dash reading is transmission failure, track not available, failure inquire mode. Car will not restart immediatly but wait a few minutes and it starts but its in a limp home gear. Once you stop it and start it its back to normal. This has happened three times. Put a reading on it and code P1111 (dummy code) and P0332 (knock sensor two circuit low out put bank 2)
Sort of like one posting where the knock sensors were cleaned and switched to determine if its the sensor or something else. Would you reccomend that action?
I have only had this car a short time. Paul

 

Paul,

What is the THUD you are hearing? You knock sensor is seeing it!

 

Do the swap and see what happens.
You could do no harm at all!

David