BMW Repair: 94 BMW 740iL Rough idle/no power, bmw 740il, smog test


Question
Just had oil change, reset idiot lites, smog test (passed)and drove home fine.
Rinsed out/lightly washed engine compartment. No hi pressure hose! Did not try to drive till the next morning.
Now rough idle and no power in gear. What happened? Plugs?
I checked for obvious wires disconnected in engine compartment and anything that may have gotten wet. Found nada. Did not check under car for something that may have been disturbed by Jiffy Lube guys.
Did not get "check engine" light at first but on now after several attempts to drive around the neighborhood.
This car does have the "check ball" problem w/tranny but I've been successfully babying it over a year without major issues. Car has always run great till now. HELP!


Answer
Washing the engine can create all kinds of this sort of thing (yet I still wash mine too).

Doubt it is the plugs.  

Likely a connector got water in it.  Try disconnecting and looking at the primary connectors under the hood.  If you find one wet, throughly dry it out.  Some spray contact cleaner wouldn't hurt either.  If you find one corroded, clean it off.

If the first doesn't work, or at the same time, look for a vacuum hose that may have gotten disconnected during the cleaning.

Doubt anything is seriously wrong.  Worst case, leave it with the hood open on a bright sunny day.