Lower end Knock V8

[72bird]

I took my 2004 4.6 4Runner with 80k miles to my local dealer last week (Friday) to have them listen to what sounded like a rod definite knock after an oil change by their dealership. This knock rhythm begins after 5 seconds of idle. It did have oil. The Service Rep said his Master Mech also said it sounded like a rod knock. Well after he verified the Certified warranty was still good we both expected that Toyota was going to repair the problem. I got a loaner vehicle for the weekend and Holiday free gratis (woo hoo)
Anyway, I got call from him yesterday and he said they has solved the problem by flushing the fuel system....... The vehicle is ready for pickup ????? What the &^%$????
This engine has never stumbled, never dieseled once and has never had any performance issues here. Is this guy feeding me a line of *&^%??? Also, this is not a warranty item and they did this without any notification to me($150). Anyone know what this can be??? He said possible carbon build up.
Guys and Gals, I have been around automobile engines on and off the track for many years. I know the sound.
Stumped... I pickup the car this afternoon

[jetwhine]

72bird,

How did it run after you picked it up? Any noises? If you don't hear any noises I would have someone else drain the oil and add new to see if Toyota has put something thicker in, to cover up the noise. If it sounds like a bearing noise then it probably is.

[72bird]

After the de-carbonization treatment, I can still hear a low intermittent tick but not at the same intensity or rhythm as originally. It's not the same noise. I'll check the oil viscosity to see if it changed from typical. I still have about 20K and a year of drivetrain warranty left on it. If it's a bearing, it will not heal itself with Motor Honey or a bottle of instant overhaul. I will take it to a different dealer if it recurs.
My wife is taking a 600 mile trip this weekend so she'll put it through the ringer. The service Rep made the mistake and gave us his cell phone number. When she's PO'd about something, she is extremely vocal and leaves nothing to the imagination. For his sake, I hope her trip is a pleasant one.