My 2014 lc200, 62,000km, developed a load whistle yesterday, starts only under load around 1800rpm getting REALLY load at 3000rpm. Measured dab today, 135 dba inside the car! Other cars on the M1 were pulling over as I approached thinking it’s an emergency siren, it’s that loud. I was towing my boat, going up gradients, whistle is loudest ( engine under most load). At idle and in neutral, no whistle, but rev to 2000rpm it starts and whistle is loud, but not as bad as driving under acceleration. Whistle stops immediately when throttle is backed off. Today, Starting the car, when cold, no whistle, drove 1km, whistle is back as loud as ever. Air box and filter are clean, always serviced on schedule at Toyota dealer where purchased. Any ideas where to start looking please?