and you have air coming out around the spark plugs as in compression? If so how many of the spark plugs all of them or just one? Take the spark plug out and check the little washer on the plug to see if its damaged or missing. My thought is you didnt tighten them properly and torque them to specs. Just get a new set of plugs and put them in and the problem should be gone.
Well I sure as hell hope it's missing,,, being all the Focus engine options use a tapered seat sparkplug.
... if you have no clue just say so.
Now as I'm reading Warriors issue;
- loud air sound
- sounds like from spark plug area
- oil present on spark plug threads / electrode
- runs rough
Air escaping from a spark plug could be a damaged plug, broken porcelain, or it can be damaged threads in the cylinder head, as noted.
Oil on the electrode can be either cracked rings (or just very worn), damaged cylinder bore, leaking valve stem seals (though this often times will show as smoke upon startup and/or deceleration).
Running rough, based on what you've done thus far, I would say is either dirty plugs or you missed a plug while reinstalling a plug wire,,, though it's also possible you damaged a plug wire while removing it, they aren't the best design and break rather easily.
Things you should also double (triple) check are that you've bought the correct spark plugs for the car; in all cases/engines stick with the factory recommended Motorcraft brand plugs. Yes running the wrong plugs can cause problems and can be severe as engine failure due to wrong plugs.
Re-check you plug wires. Ohm them if need be to ensure they are still decent. Make sure you get the boot on the plug all the way.
Compression test is a good idea. Most parts stores should have one you can rent. Just remember to remove spark and fuel during testing (ie disable the fuel pump and ignition by removing fuses).
