I have filled up with sub 93 here and there. I had just completed a 700 mile road trip through Kentucky, so not sure what quality of fuel I picked up along the way. I thought I read on the forums that it will result in reduced power, but the engine compensates for reduced octane. I'm primarily filling up at Circle K. Not quite sure how they rank on the fuel the quality scale. What cleaner do you recommend, if not this one?

Do you think the video audio sounds like spark knock? I haven't been able to find many videos on the subject, especially Land Rover. The videos with knocks seem to be much different / a broke part.

Fair point on cashier, but at this stage, the Land Rover dealer has not solved the problem, and neither has the local European Indy shop 🤷

 

If you’ve been fueling up there with anything above 87 you shouldn’t be an issue. If you are getting knocking you would typically get codes with that too. I would recommend Lucas or Chevron fuel system cleaners. Often on sale or BoGo at auto parts stores. Have you ruled out the front coupler on the supercharger snout? A known issue though I’m not sure the sound matches up

 

TheMacMan
Did you have to disconnect any coolant lines to change the plugs?
My shop manual shows a couple of lines to disconnect to get them out of the way but I suspect it's not required.
See step 4, 5, and 10 of attached file please.
That's why I've been putting it off until a coolant change but I won't wait if it's not necessary.

 

I did not disconnect any coolant lines. There is a wire harness on the left side that is a little tricky to get out and there's definitely not much space back there. He details how to unclip it in the video. I try to be as gentle as I could around the small tubes that are on the left side. They are pretty flexible and I have a lot of wiggle room so nothing was damaged.
I also did not disconnect the battery ground. Hopefully that was not risky leaving it attached 🤔 I assumed there would be no electricity flowing if the car was off.

 

Thanks for your reply.

 

I don't know. Maybe the socks?

 

Any video on the supercharger snout issue?

Does spark knock happen if the vehicle is in neutral and the engine is revved? There are zero problematic sounds when I rev the engine in neutral. Most of the videos I could find compared spark knock before and after from neutral.

Would spark knock cause a CEL or be measurable with a GAP IID tool?

 

I'm not the best garage hack out there, but, I think pre-ignition knock will most likely happen when the engine is under load, not parked and revving. I didn't see anything crazy with your spark plugs that would indicate a persistent lean or rich condition, or signs of a coolant leak into the cylinders, or oil consumption. To me they look pretty good.

It'll be interesting to see what you've found to be the cause of this engine noise.

 

One other thought, is there an easy way to disable the supercharger or take it out of the equation to see if the noise is still present without it? I'm guessing the engine will run if it's completely removed, but that sounds like a much more difficult procedure.
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I drove it 150miles today and popped a new bottle of cleaner in it. It's been through one bottle of gumout, half of that on the highway, and new spark plugs. No change yet!

Alabama clay sure is thick and slippery!

 

No, this motor will absolutely not run without the supercharger on it. ECU will lose its mind.

Again, have you looked into the supercharger snout possibly being the issue? They are known to go bad and cause noise. If you’re dead set on getting this resolved I’d take it to a good shop (Bear Valley mentioned) instead of trying a parts cannon