Sayeed

My ML 430 was sitting around for year and a half collecting dust. I decided to start using again. decided to power wash the engine - what a mistake that was!!!
Now I have few codes mainly misfires. so i decided to give it a good tune up and clean any moisture. I was getting 3 different Cylinder misfires. I pulled off all the ignition coils, clean them up, installed new spark plugs. put everything back together. Now, the truck still runs rough and getting same codes.

P0305 - Cylinder 5 misfires
P0720 - Output Speed Sensor
P0700 - Transmission Control System

I have a feeling that the coil for #5 is shot and the other codes are results. Any help will be appreciated.

Thank you

tali1

That's happened to me as well except in my C5 vette. The thing that I would do is let the motor run for a few minutes idling to dry out any water from the motor's heat and 9/10 the misfire would go away. Was the motor on while you were pressure washing it?

Sayeed

its been 2 weeks drying but #5 would not go away. all others dried and working fine. I replaced the one coil this morning and the problem is over for now. I bet I shot one of the coil. they are old.
thanks.

IgorE350

When you planning to power wash your engine. Take the battery out, power wash it, then take a leaf blower, dry it real good. After that let the car sit on a nice sun for a day or 2 with open hood. then you can put the battery back and start it up. You cant power wash ur car and expect to work just fine after u blasted it with water.

khomer2

I method that works for me.