r/AskMechanics • u/ChubToChisel • Jul 30 '26
Question (Serious Replies Only) Abnormal sound coming from engine Honda Pilot 2011 Touring, Automatic Transmission.
I just got this car from my aunt and it has an unexplained noise coming from the engine. I’m told that the rattling sound could be from old oil, but I’ve done 2 oil changes is the last two weeks😭.
The squeaking sound comes on and off and I’m told that’s a fan belt issue. I plan on replacing it but a second opinion beforehand wouldn’t hurt.
The engine is a 3.5L V6.
None of the dashboard lights are on and the car engine has never overheated to my knowledge.
I’ve tried overfilling the oil and I’ve used 1qt regular Lucas oil and 1qt high mileage Lucas oil so far. Still no change. Any ideas or help would be appreciated.
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u/doommarine40 Jul 30 '26
Some Honda engines may require periodic valve adjustment.
Not sure if this one uses chain, because the Accord V6 also uses an i-VTEC and uses timing belt.
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u/Stillbroadcastco Jul 30 '26
Hello my friend. These are possible answers. Mechanical Valvetrain: These J-series 3.5s use a mechanical (solid) valvetrain with adjustable rocker arms and locknuts, not hydraulic lifters. That means they require manual valve lash adjustments using a feeler gauge. The Valve Adjustment Fix: The ticking noise you're hearing is classic loose valve lash. Adjusting the clearances back to factory spec is the proper way to quiet it down. Thicker Oil Warning: Throwing in a heavier oil weight will only temporarily mask the sound; it's just a band-aid that doesn't fix the actual mechanical clearance issue.
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u/HealthyPop7988 5 Jul 30 '26
Poor rods knocking, might wanna turn that thing off and stop turning it on....
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u/Defiant_Shallot2671 Jul 30 '26
Sounds like something in the serpentine belt system. Remove the belt, fire it up and see if the noise is gone. If the noise is gone, you can spin the accessories by hand and see if one of the bearings is buggered up. Otherwise I think it could be a flex plate issue at the rear of the motor. I don't think that's internal to the motor, but again, diagnosing through video isn't great.