4.7 vvti engine tick (1 Viewer)

[Duiser00]

Figured I’d post and see if anyone has heard much of what I just ran into w my 06 470.
257k extremely clean well maintained. Was running fine after plug and coil pack replacement for several hundred miles and suddenly stumbled at a stop light and threw cel. Ran it a few miles home and noticed a loud ticking from drivers side rear almost like a broken rocker arm or collapsed lifter. Noise is consistent w rpm. Checked all plugs again and for anything noticeably loose etc. code was for misfire. Decided to have it towed and mechanic said timing belts etc all intact except one valve shim had come out. Odd? He looked in each cylinder for any damage w a scope said they seem fine and he put the shim back in apparently and started it and it came back out w noise resuming. Haven’t been able to find too much on this on the web but did see some people discussing the vvti as a possible culprit. Appeciate any feedback or thoughts on this as it’s been suggested an engine or new head may be in order.

 

[awesomeissquid]

So to confirm they pulled the timing belt to reinstall the valve shim? Because the buckets are under the camshafts which require the timing belt be pulled.

 

[Duiser00]

So to confirm they pulled the timing belt to reinstall the valve shim? Because the buckets are under the camshafts which require the timing belt be pulled.

Yes also wanted to note he’s telling me no more codes just the noise and the threw the shim again.

 

[2001LC]

First I've head of in a 100 series..

I'd consider valve seat, bad spring, bent valve stem and or cam damaged. As very likely cause(s) if shim falling out.

I'd also check if engine VIN # matches vehicle.

 

[Duiser00]

First I've head of in a 100 series..

I'd consider valve seat, bad spring, bent valve stem and or cam damaged. As very likely cause(s) if shim falling out.

I'd also check if engine VIN # matches vehicle.

I’m second owner was a lease turn in so no issues on vin. It seems odd that it stumbled and developed the noise I’m not sure how dare would occur or what could have failed.

 

[awesomeissquid]

So for the shim to get loose, there would need to be some sort of gap between the cam and the valve top. @2001LC listed the items that could have caused this.

 

[Duiser00]

So for the shim to get loose, there would need to be some sort of gap between the cam and the valve top. @2001LC listed the items that could have caused this.

Posting an update: apparently it was the vvti mechanism on drivers side. Definitely quieter now but def louder than before and I’m not sure why. Sounds more like a 5.7 now any ideas? Timing belt was also performed when the vvti mechanism was changed along w vvti solenoid.