Your engine is a four stroke engine. The piston comes up and down twice in one cycle. One of those times is for compression, the other is to push out the exhaust fumes. Your piston may have been coming up on the compression stroke or the exhaust stroke.

If the piston came up on the compression stroke with the wire in there, the valves would have been closed. If the piston was coming up on the exhaust stroke, the two exhaust valves would have been open and possibly damaged.

TDC is top dead center. That is when piston #1 is up all the way on the compression stroke.

The valves are spring loaded and look like an upside down T, like this l

The valve spring pulls the valve up to close the valve against the top of the cylinder head. The rocker arm pushes the top of the valve down to open it. There is a small gap between the rocker arm and the top of the valve that you can measure using feeler gauges.

First, go to the Common DIY Threads at the top and download a shop manual (for the 5th gens I like the spoonerturner one) or buy one.

TDC- Top Dead Center. Usually when doing a tb job you put #1 cyl to TDC. Then begin work. Get the manual to double check memory, cam gear has an "up" mark, well that is "up" and the crank gear/flywheel has a mark as well. Both of those at the proper position, cyl #1 is at TDC-again the manual has pic's and more description.

Valve lash- the clearance between the "rocker" and the top of the valve stem. If out of spec then a hung/stuck valve would/could be an issue....wire keeping the valve(s) open.

Last "out of the box" idea before removing the head. Copper should melt before any of the other metals in the cyl.....so, a pencil type torch might help soften the copper enough to get it out of the cyl....again, don't melt it but if it gets soft enough ????

Good luck

EDIT: I see my fried PA posted as I was typing...Thanks

Stop !
 

You know in your gut that you are screwed with that blob in there.

DO NOT PUT HEAT into the plug hole !!!!!!!!!!!!!!!!!!!!!!!!

It WILL melt & make a hell of a needless mess.

Run the engine & you WILL BURN the edges of both valves because the probably will not close due to the copper wire. # 14 or # 12 or # 10 guage.

Set the engine to a " take apart cam timing " according the shop manual.
Go to a dealer & honestly tell ONLY the service manager how you screwed your self. He will probably copy the pages from the shop manual. OFFER him $ 20 if he would copy the pages on the cam marks setup.

You can handle it from there.......Or bite the bullet & have them do the job.

Agreed, do not melt the wire...but if you get it soft enoungh...and follow the other suggestions....maybe.

The manual from spoonerturner is free...download it and see if it answers the the questions you have. If not then pay someone, I've seen sellers on e-bay where you can get the whole manual for $22.(manualsourse ?)

Neither the water pump nor the timing belt has to come off. If the engine will rotate enough to get it to #1 TDC on the compression stroke (distributor rotor pointing at #1 distributor cap terminal), take the rocker assembly off, and just flip the cam up to get it out, reversing that operation to put the cam back in. Just make sure the timing is correct and reset the belt tension.

Pulling the head pretty easy. Use new gaskets, use a known-accurate torque wrench, and make sure the head bolts and the holes they thread into are clean. Follow the FSM torque sequence exactly.

Yea there is a way around the t-belt....

OP- Personally, if I was going that way. Remove just the cam gear from the cam and slide it off....watch out for the key.

I use to know somebody that changed cam seals this way.....anybody seen/heard desert in a while? We traded PM's a few months ago, PM me if you have any news.