Hey all, I always washed all my engines off at the car wash and I did it again today with my 99 GT 4.6 for the first time and the check engine light came on for a second and went off , the car now is running terrible. Will this go away after the engine drys off? Do I need to set the ECM by disconnecting the battery? Or is it a shorted out sensor that is going to have to be replaced? I would appreciate any assistance as I am a new member. I have had two other Stangs with no problem when engine was washed.

 

Water could have gotten in between the COP's and spark plugs. Did you cover or avoid any areas like the fuses, alternator, battery, air filter, etc?

 

+1 check that out and if u didnt avoid those areas or cover them shame on u haha

 

Sounds like you soaked a COP. Pull the codes and see which cylinder is missing, replace that COP.

 

How is it running crappy?
i washed my engine off and it felt like i missing a cylindar. turns out i had got water down in the plugs and needed to change them out.

 

if you didnt get a lot in there just let it sit for a couple hours and you should be fine. let all the water dry up and you should be good.

 

Yeah I tried to avoid the trouble areas but at the same time I needed to get 10 years worth of grease and spilled/leaked oil off of it. I just purchased it 5 days ago and it ran liked a crazed cat until I sprayed it off and the light flashed on then stayed off. It should have a stored code from the flash but I thought I might be able to reset whatever may have gotten wet and shorted by disconnecting the power for 30 secs. I guess I will pull the plugs torrow and see if it cracked the porcalin and go have it scanned. Thanks for the help, I will take any suggestions at this point I am clueless, I miss the 5.0 never had that problem when washing it off.

 

how long ago did you wash it?

 

you got water down in one of the spark plug holes. The plug will be corroded when you pull it out. Need to go buy a new one and next time dont douse the engine with water

 

ur not spose to put water under the hood..lol...but check ur maf too. my MAFia got messed up from just being under the hood while washing the outside. cost me 300 bucks to replace it.