I let someone test drive my RX330, the engine was cold and he raced it over redline. He was gone only 5 minutes, and returned with a massive clattering sound coming from the engine – it was audible over 2 blocks away. It sounded (to my inexperienced ear) like a valve had broken and fell in to the chamber. I took the cylinder heads and valves off but found nothing. No broken valves, no broken springs, and the chambers & piston heads looked fine. I’m not a mechanic and really at a loss for what could possibly be going on. Can anyone offer a suggestion? Thanks

 

If you didn't see anything on the top, then it might be something on the bottom (bent rod, spun bearing, ???). Is it there when it's just idling in the driveway?
You might consider claiming it on your insurance since this yahoo obviously joyrided (joyrid? joyridi?) in it and tore your baby up.

 

I'm not sure if the 330 has a timing belt, but if it does, it could have jumped a tooth on the pulley and now it is seriously out of time.

 

I am a little confused [not hard for me ] . you said inexperienced ear , not a mechanic , And you just took the heads off your engine . Wow that was a gutsy thing to do . Sounds like spun main or rod bearing . With the heads off all you can do now is pull the engine and take it all the way down . Big big job . Let us know what you find . I would be so ------off . did the guy say anything when he brought it back like that ?

 

And you let him just walk off?

 

Unless you do it yourself, in which case you're out a couple hundred bucks.

 

Thanks everyone for all the input - really appreciate the advice. Guess I need to pull of the oil pan and start from the bottom.

Yes, it's there at idle. When he parked it back on my driveway the noise was still there. He got out and opened the hood, then I turned off the engine. Yeah I let him walk off, I couldn't think of anything to do that would not cause me jail time. I doubt there's any legal recourse, just a very expensive lesson.

Yes, its got a belt which coulda skipped. I snapped some pics before removing it. Unfortunately I didn't do a compression test or measure the intake manifold pressure to avoid more damage to the engine. Guess that was a mistake too~

Anyway, thanks again- I'll let y'all know what turns up...
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I say he'll lie anyway. Better off to take one on the chin this time as "stupid tax" and remember from now on that if someone's test driving your car, your butt is in the passenger seat. Every time.

You might just put it back together and take it to the toy dealer for a diagnostic. They can tell you what's wrong with it and you can bring it back home and fix it.