When one gets the KS code, when there is a malfunction or a KS fails,,, did Jaguar build in a fail safe that shuts the engine down - completely prevents driving - with the idea that continued use could potentially lead to a catastrophic event?

 

as far as I know, no shutdown, but I’ve only experienced one of the two knock sensors going bad. In my case, the restricted performance light came on which restricted rpm to under 3,000.

 

I have a 32v car from the 80s with no knock sensors,,, it asks for high revs (that I rarely give it), it has no knock sensors and the compression ratings are much higher than the XK8s... Personally, I don't like that jaguar decided to restrict performance the way it has due to many of the issues,,, many of them momentary,,, in regular driving. In some cases it just seems ridiculous... That's just me.

 

Its a bit more complicated and can't be compared to an older engine, I just googled quickly for a document that helps explain it more how its being used in modern engines, and why it is better (as long as you keep it working):
https://motorsport-developments.co.u...Detection.html

 

I’m all for every system on the car to be in good working order. I take pride in knowing every car I’ve sold was in better shape when sold than when I purchased it.

However, I feel that some of the engine safely systems are redundant and unnecessarily add complexity. I have no doubt the knock sensors can help out when there is an issue with engine knock.

But my little experiment is telling me that an engine in good running condition can function perfectly fine without both knock sensors in the optimal locations.

After all, Jaguar already has a system in place that is changing the timing whenever the engine is accelerating at high rpm, completely independent of the knock sensor input.

if I can successfully fool the engine into thinking the knock sensor is in place, then I’m going to do it and not worry about it until next spring when I plan on relocating the knock sensor back to its factory location .

Z

 

You still don't understand how it works, but I wish you the best.

 

Unnecessarily condescending.

I do understand how it works. More importantly, I understand that the car is working fine without it in the stock location.

Do you understand that ?

Z

 

I understand that you don't understand, you prove it again with your comment "the car is working fine". don't take it personal though, I wish you the best.

 

Sorry zray but I agree with avos

I have just read through this complete thread and it is obvious you do not understand the true operation of the knock sensors and the relationship with the ECU.

Also your fitment is flawed as Piezo sensors are affected by strong magnetic fields, now how have you attached it again ?

Still your car/your money/your risk

I also think a mod should place a "Do not follow this advice/work around hack/bodge unless you are aware of the risk"

 

It's a Porsche, average compression ratings can be well upwards of 125lbs per... Of course it can be compared... Early detonation is directly related to high compression, lower octane fuels, high revs and lower flash points. Hot spots in cylinders, carbon spots that become red hot, and...

What can't the two be compared?

Anyways. My XJS, folks one the forum encourage and do perform many many shortcuts to to simplify the unnecessary or over engineered in the 70s 80s and 90s V12 and somehow that is done without raising a fear culture on the subforum and I am so grateful for the - if it works work it - tone.

There will be a day with these cars where cutting them down to there near rawest will most likely be needed. I don't know how that is possible with the CAN system the way it is in these things,,, but keeping up with everything that can have one limping home, as the components fail, sounds pretty miserable. That's just me...

 

This is a dangerous and very misinformed thread now and needs to be assessed by a mod and possibly deleted as it could easily do more harm than good.

GGG please read this thread and see what you think.

 

Well, actually the idea of connecting external sensors to the wiring harness without having to take the entire top off, has been helping in my hunt for a engine fault.
Just for 10 minutes. Ignition on my engine still retarded by ECU, but could be sure it was not by knocking sensor signals.

Would not risk running an engine like this. ECU uses KS to regulate (prevent running too lean and burning holes in piston, or drop seats)

 

Double post.

 

Thank you to all who posted comments. I have been inspired to go buy a full tank of gas and go for (another) trouble free ride.


Z

 

The very title of the the thread is "HACK"...

Anyone who comes here,,, from the title and first lines,,, KNOWS that it is not offered as, suggested as,,, recommend as a FIX of the permanent type... It's clearly stated... It basically suggests, do at own risk...lol

My v12 has ZERO knock sensors. 150 to 200 plus psi. 12 cylinders, zero knock sensors. We listen for knock. Then fix if needed... Engines have knocked since, forever.

The idea that it is being suggested that this be censored, deleted and removed is,,,, well - personally I think it's sad. A shame.

When folks use perfection-ism, when they can state show or suggest that someone has done something "wrong",,, should that really give them the power (in the name of caution, fear and) to suggest that they be censored and that the idea be erased from the annalllllz... Abstract notions of perfection used as some sort ah weapon??? It's boring.

More, the willingness of folks to make others feel like *#@@$#@ because we haven't met or reached some arbitrary (their) level of acceptable perfection-ism is completely unappealing... Off turning. And sadly can become the overarching culture of a forum, agency, institution and so on,,,, where the initial design is open dialogue and the open sharing of ideas. Without CHECKS these tendencies of somes version of perfection can get out of control and dominate and ruin the culture of a group. Again, sad.

Me, personally, a guy who is in his first days with rescuing an XKR, who would be somewhat dumbstruck with the idea of removing the whole top end of the engine (or paying someone some CRAZY amount of money to do it) to replace a 100$ sensor might give up on one of these beautiful cars because of FEAR and the inability to find a post where some one ingenuously and temporarily found a HACK solution. Due to censorship...

Leave the post up! We are all adults here. Let people choose for themselves. Live with their choices. I'm with freedom and liberty, the freedom and right to choose and all that good stuff, lol. Fear is often used to rob us of freedom and liberty, I say.

Jeeeeeze... This is a car forum!

 

Agreed. Nice speech! Must be the air.

 

Lol... That's what my Mama says to me!!!
All.the.time...

 

@JayJagJay
Post #25 and #35 doesn't tell anything about how the software is controlling the engines mentioned, and that is where the danger lies.

The Jaguar ECU has with the Knock Sensors the ability to adjust it maps in such a way that it runs most efficient (so best power and economy) by flirting with situations where knock can occur, and this under different load situations (so not just WOT!)

Take away the ability for the ECU to detect knocks, and you are in a higher danger zone than engines that where tuned outside the knock limits.

Hence the reason why Jaguar will put your engine into "restricted performance mode" if it detects a malfunction of the sensors.

Important note for those that have a AJ26 Supercharger ECU as that one does not have the ability to detect Knock at WOT. The ECU was not able to distinguish knocks with the extra noise from the SC, this was only available from the AJ27.

@Stumpy
Spot on with the Magnet, that for sure disables the knock detection.

@Ekskaar
I had installed extra knock sensors (Phormula) during my project phase to check if (and where) knocks actually occur. To ensure the ECU was not correcting any knocks, I also had disconnected the original knock sensors and connected the leads to ones that where not attached to the engine. This way the engine would not go into RP mode and would not correct any knocks in order for me to check directly if/and where knocks took place. Of course only briefly during test runs, as to me its not worth the risk to run without that build in safety.

 

Thx Avos, Is there any way to read ks signal with simple ELM327 or Icarsoft? Would be helpfull for me. My engine keeps retarding ignition even without KS, without WS connected...expect signal problem somewhere (stumble under WOT thread)

Groeten Rob😉

 

Dag Rob,

Unfortunately, this is not readable with the 4.0 engines or the 4.2. From the 2006 model there is more to see, especially from the 5.0 cars, a Walhalla of info with the Jaguar tools ;-)

I'll check your your thread now.