Oil in spark plugs

Car recently overheated. Replaced thermostat and housing, and one hose. Drove form Michigan to Florida, no problem. Got to Florida and two days later car would turn over but not start. Checked the plugs and all four had oil in the chamber when I removed the wires. I'm planning on sucking out the oil with a shop vac and replacing the plugs and wires. WHat might cause the oil to get in there in the first place? Oil level on dipstick does not seem to have changed.

try compression test and get back to me

Any time you see oil getting inside of the spark plug and wires means that the spark plug tube seals are bad and are letting oil from the heads cover into the spark plugs solution will be remove the head cover anf replace the spark plug tube seal

sounds like you could have some junk in your coolant system. I would try a complete flush maybe a couple of times with just water pumping through. you can get rust in there and even with a new thermostat as soon as a chunk of rust gets back to the thermostat ot can stick closed again.

Could be three things: Hopefully the first...
1. radiator fan not blowing. (most likely)
2. Radiator clogged (not likely)
3. Head gasket blown... (very possible)

If #1, system cannot detect fan not blowing. It may be the fuse or the relay switch, disconnecetd wire at fan, or burned-out fan motor.
If #2, Flush radiator
If #3, you will see WHITE smoke out the tailpipe and excessive water drops.
Your new oil will have a "milky" look (check the oil dipstick). That is water.
When engine is COLD, remove radiator cap and start car. You will notice high-pressure "bubbles" squirt out of the radiator, even before the engine warms up.

I hope it is #1. and that this is helpful.

There are two freeze out plugs at the rear of the block (V8) and many v6 engines. If coolant is coming from where you say, likely they have failed. Unfortunately, the only way to reach them is to remove engine or transmission, It's rare that they fail because they are "protected " by the bellhousing, but can still rot from the inside out. There is no sealer known to man that will fix this. It's a shame that you need to do all that work for a pair of $2.00 plugs, but that's what needs to happen.

change the mass air flow meter