I have water dripped to lambda O2 connector, the car then running super lean 20++ not good for engine health. I had to pull o2 and run entirely on open map a day then it self  recovers.

Washing engine bay maybe OK for new car but for old car, used car heck nope. 

 

 

Edited November 11, 20196 yr by Coremouse

engine compartment should always be clesaned by high pressure steam !   Not a good idea to use high pressure wash on electrical items !  I agree with putting a plastic bag on the alternator , protect the ECU /chip and disconnect a terminal on the battery !    

And are you happy with the quik car wash at Pattaya Sukhumvit ? My car has never been really clean after going there !