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Discussion Starter · #1 ·
I’ve noticed a clicking, maybe even a slight grinding noise coming from my ‘15 Juke. At first I thought maybe it was a serpentine belt, or maybe the timing chain, but as I chased the noise is seems like it’s coming from the back of the engine-intake turbo side. It’s pretty noticeable even with the hood down and latched. While driving the turbo spool sounds fine, and boost (at least through my OBD2 reader looks fine). Could bearings be going out? Impeller loose? Something stuck inside? Is this the start of something serious? Any help would be appreciated
 

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could also just be the high pressure fuel pump. It sits on top of the engine on the intake side. They are noisy.
 

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FYI your OBD reader will not show boost. If it does, it's fake. The ECM does NOT send any info about 'boost pressure' only a voltage that would have to be translated to 'pressure'. Trust me on that. Agree that it is most likely the HPFP cuz ya, they are loud...
 

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Just because it's voltage doesn't mean it's wrong. If you calibrate torque correctly for your vehicle and actual atmospheric pressure, they should have no problem matching each other. The only real difference would be where a real boost gauge is tapped into the system vs the map sensor location.

Voltage and map is good enough for the ecu to make decisions, so I don't see why it wouldn't be a trustworthy signal as voltage.
 

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That OBD 'gauge' is calibrated for what? A Juke, a Ford, an SRT? It doesn't know what the signal coming from a boost pressure sensor is... Agree, it could be correct but it has to know the signal voltage being sent to the ECM and it's low/high limit to be correct. Hell, my boost gauge tapped right in to almost my throttle body never goes past 12psi but sensor says I'm +14 and I know I am so can't trust anything anymore ;)
 

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Hence calibration is needed. My current understanding is that the voltage provides a reading of absolute pressure, meaning regular atmospheric pressure + boost. Sea level is something like 14.7 psi. If you max boost its another 14. So the max voltage reading the juke provides to the obd2 should be translated in torque as 28.7 psi. But if you are at say 3500 ft altitude, then your atmospheric pressure is really 1.7 less than at sea level. So your ecu is telling the obd2 that you have the voltage for 28.7 - 1.7 = 27 psi. But since your torque isnt calibrated for your current 3500ft altitude, it takes the 27 an subtracts 14.7 (or whatever the uncalbrated, default correction in torque is) and gives you a reading of 12.3 instead of 14. Torque needs to be calibrated for your actual atmospheric pressure vs sea level.

A boost gauge doesn't care about atmospheric pressure since it's reading the actual closed system pressure.

At least I think that's how it works. My sea level and altitude numbers are probably not correct, but the concept is there.

Edit: link to torque wiki topic
 

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Discussion Starter · #7 ·
Just wanted to give an update...it was the timing chain. Waiting for more info from the dealer but it should be covered under the powertrain warranty.
 

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Just wanted to give an update...it was the timing chain. Waiting for more info from the dealer but it should be covered under the powertrain warranty.
Oh geez that is too bad.

Best of luck with the dealer

Let us know how it goes.
 

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They cannot for that. They would have to prove that the timing chain failed because of them. Its impossible to do. The timing chain is a rotating internally lubricated engine part. In no way can a Cat Back cause that to fail. The IC is just a larger version of what the Juke already has. There is no way they can prove that a BETTER,larger, IC that is part of an induction system can cause the chain to fail. Its impossible.

 

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...Its impossible.
Unless the dealership takes the cheap and cowardly way out and claim the cat-back and intercooler are evidence of strip/street/auto-x racing and causing the engine to work harder/outside the normal operating parameters thus putting added/extraneous/unusual stress on the timing chain components otherwise not seen during "normal" driving. And they'll demand and scrutinize every single oil change and service record whether you had a shop do it or you did it yourself. Entirely plausible depending how shady the dealership wants to be. Saw it happen to my friend and his '16 Civic 1.5L Turbo. chain stretched and was making a racket under the hood and Honda claimed he was drag racing with an intercooler and cat-back... he dumped that car and bought a 1980s Toyota 4Runner.
 

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Claimed. That's the whole thing that is wrong. They have to prove.

Now they can prove that you did not change the oil etc so that stuff is on you.
 
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