Hyundai elantra missing

my brother gave me his elantra with 160000 miles,he got all schedualed maintenance,the check engine light came on and the code came back #1 plug missfire,it would miss when first started but smooth out after a min.the second day i had it it missed real bad,i got 4 new plugs and when i pulled the boot out of # 1 it was coverd in coolant,i put the new plug in and it misses bad but after running it i dont see any more fluid on the boot. there is no coolant in the oil and it won’t overheat. is there anything i should check before pulling the head,the timing belt and water pump have about 25000 on them.

Pour some leak sealer(coolant compatible) in the radiator and keep an eye on the coolant level and the oil for now. Apparently there is a crack in the head at the spark plug well. Hopefully it won’t spread out to contaminate the engine oil… Are you certain that the coolant wasn’t spilled on the engine and drained into the well?

i have driven this car several times now, we have not seen any coolant on that boot, seems to miss the most at idle,or accelerating.i put 2 cans of injector cleaner in and cleened all the new plugs,they were all white,the car sat for 6 months,i bought a new set of wires ,i will put them on today,i was thinking of getting the compresion tested also.

o k changed the wires, took the batt cable off,started it up, ran great all day. started it up a few hours latter and it started missing again,check engine lite came on again. there was no coolant anywhere,smoothed out after 5 min of driving. must be a sencer because of the cold weather.

You need the codes again to find out whether it is still cylinder 1. (I am assuming that the code was P0301). A cold-only misfire on only one cylinder is not at all likely to come from a sensor problem.

The misfire codes also do not indicate plug and wire problems. Plug & wire problems are common causes of misfire & misfire codes. They are the things to check first. I would check the compression next.

went in and they said #4 miss fire,he said the champion plugs i put in were junk,replaced them with n j k,i pulled the batt cable off and reset the going to test it out today.also i checked to make sure all the wires were locked in the boot right.