The rattling stopped because the metal piece or screw either flattened out or left the combustion chamber throughout the exhaust. You will have to remove the head to do a valve job if a valve(s) got messed up. Continuing to drive could cause more damage to the piston(s) if more than one tract lost a screw(s). When you get the surge chamber (That’s the butterfly cage) off do the fix by removing the rest of the blades and plugging the shaft holes at the ends. As long as the piston(s) are not damaged you should not halve to get into the bottom end. While you have the top end apart replace the plugs, wires, pcv, and y-pipe on the backside for the heater. Best trick I found for keeping the electrical connections and hoses straight is tag or mark each end with numbered wire tags. 1/1 2/2 3/3 etc. It's a bit time consuming but effective. Good luck in your repairs.

 

Cylinder numbers

Thanks for the reply that will help alot! Can I just fix the valves that got damaged? And could you give me a number for each cylinder?

How would be the best way to find the damaged ones?

 

To do it right you will need to pull both heads. 1,3,5 are on one side and 2,4,6 are on the other. Don't just fix the bad ones. Unless you have a way to check them then getting the heads to a shop is the best way.

 

Sounds like another bit fell off the butterfly system and did not pass through the engine .... its bent a valve which is now partially stuck open and the hydraulic tappet is at full extension but not long enough to stop the tappet rattle ....Before you take both heads off do a compression check and see if it got both cylinders .once removed with the valves closed you can fill the areas behind avalve with light oil and see if it leaks past th valve or feed comressed air into the plug hole before you remove the head ( make an adaptor ) and see if it hisses out the closed inlet/exhaust valve. If you take it off you should see marks on the pistons where they have kissed the pistons.....the kiss of death that is ......take the butterfly system out and put a threaded rod through from end to end perfect fit not required between the header runs but the ends must be sealed.
If you are lucky one of your misfires may be that the plug gap has been knocked closed ...but the other seems like a bent valve....

And for the rest of you unplug the butterflys ..you have been told

 

Butterfly knocks

I was hearing a knocking sound for about 3months, I thought it was internal at first like a rod bearing. After reading all about the butterfly problem I started to investigate more and more. After about 2 1/2 months I unplugged the butterflys and my noise or knocking stopped. So I thought it was fixed my problems over, right. I was still listening to engine while driving and I noticed you could still hear the noise every now and then.

So this started making me think maybe it is a rod knocking or bearing in the bottom of the engine. But it did not make this noise near as often as before, maybe about 1 out of every 20.

But all the time the knocking I was hearing was the butterfly's making the noise. They was all ready loose and rattling or knocking to me. So this means once you start hearing them it is to late to unplug them, they need removed at this point. Because mine fell apart about 2 weeks after I unplugged them and damaged my valves and I am lucky that is all , it could have been the pistons and maybe more.

I should have took it apart and removed them when I started hearing the knocking sound. But I was unsure of it all and was still diagnosing the problem. But now I know a lot more about it.

 

I know this post is a little old but I could use some help! From my understanding the Sorento and the Amanti have the same engine (mine is a 04) 3.5l V6. On Friday the 2nd I was driving 35-45mph, the car hesitated slightly and started making a clicking or tapping sound. Once the car was shut off CEL came on, misfire #6 and limp-home mode (1196 i believe). Car has 94k and I do not have a warranty as I am at least the second owner. Took it to one shop wouldn't diagnois it because they said it was a "knock in the botton end." Second shop said it was a tap in the upper end, probally a valve or rocker arm, took it apart everything looked and acted right to the mechanic ( this was today and there computer was down so no help after a visual inspection). I guess my question is can and does this problem translate to my car. The tap or click is consisant with the RPMs the car is running at, lower RPMs or idling it is very faint but there, higher RPMs loder and faster. Any help would be great there isn't much help in the Amanti section.

 

not sure if your engine is in bits or together ..if its together feed compressed air into the plug hole and see if it leaks past the valve ( tdc compressoion) .you will hear it in the inlet /ezhaust tract... if its dismantled then you need to fill each combustion chamber with parafin and see if it leaks past he valve...you should also see marks on the piston crown and with valves removed possible damage to the valve seats......

 

If you have it apart you can also look at the butterflies themselves. Look for missing screws or bushings. If they are damaged in anyway remove them and put a rod in and eliminate the possibility of future damage.