2004 PT Cruiser Turbo rough idle

Just picked up a new car and I need some help diagnosing a rough idle.
Here are the symptoms: cold start is smooth, but as soon as it comes off high idle, it starts to run rough. Anything off idle is smooth, drives fine otherwise.
What I've checked so far: cleaned PCV valve, checked for vacuum leaks on the intake manifold, cleaned throttle body and IAC.
No codes. Unsure of when the car's last tune up was.
I was going to pull the plugs and check them next. Any other things I should be checking?

Car has 174K miles with a newer engine with approximately 50K on it.

Thanks.

-Dave

Is it really a rough idle or could it be grounded out motor mounts?

I like where your head is at with this. Usually when the motor mounts shart the bed, its very apparent. O
P.- want to test this theory? Just firmly grab the valve cover and give the engine a few good rocks. Worn mounts will allow the engine to move a few inches fore and aft with no problems. If you find it worn, spend the time and money and replace all of the mounts(3), its worth it. The turbo cars go through them easily. Advance auto used to sell an upper mount that was filled with polyurethane to all but eliminate breakage and not transfer vibration into the cab of the vehicle.

Pull plugs, check condition and the gap- if its a factory replacement engine, make sure your plugs are gapped properly.
While the vehicle is idling, spray a mist of water over the plug wires. Look for sparking. The oem coils on these are good units, the plug wire are known to degrade due to excessive heat from the turbski.
Make sure the throttle body is spotless and free of oil.

Let us know please

Not much time to work when it's dark outside.
I was able to check a couple things: Motor mounts are good. Not much movement.
Sprayed the wires down in the dark and couldn't see any arcing.
Planning on pulling the plugs out this weekend and checking the gap. (didn't want to do it when the engine is warm)

Check the turbo hoses to see if they are snug and not torn.

I have an 04 Turbo PT.
1) Replace the plugs and wires together. We do ours about every 50K miles.
2) Then, if you don't know the car's history, run some injector cleaner through the gas. We do that about once a year.
3) Inspecting the hoses is also a good idea. It gets hot under those hoods and the heat doesn't help old hoses, and that 04 PT is 18 years old.
4) Very little engine shake doesn't mean the engine mounts are still good. We had one set where the rubber crapped out and the bolts sat on the steel plate, very little engine movement, but it sure had a rough idle. You need to inspect each mount. The current engine mounts on our PT is the 3rd set at around 140K miles. As stated, replace them as a set. Gene

Do a compression test

Had rough idle on my 07 pt and it had a couple burnt valves. $1500 later it was fine.

To conclude this thread-
It needed new plugs and wires. Car is running smooth now.
Thanks for everyone's help.

glad it was a relatively simple and inexpensive fix !