Maybe, because it may trigger the "Engine Check Light" due to engine misfiring (as your existing engine rattling).. or some other reasons (electrical short, damaged seneors...). But if you have been driving like that in last few days and see no bad indicator came up, then I think you will be fine.

It had happened to my friend's 98 Celica and I found water vapors inside the distributor cap. I wipped it clean and rattling went out a lot, but it was a good sign saying "THE CAR NEEDS SERVICE! HELP! The water came through the dist. cap because the seal is no good...." so my friend left it a few days and came out normal.

The plug wires usually have oversize rubber cover plug's tube openings. It is hard to make water getting into it even it is pressurlized water, unless you filled water all the way up in the tube and soaked the wires (I really don't think that is possible!)

Also, I don't think water would drip into the engine head), because even air can not get throught it.

Edit: Again, good luck!

 

One last thing,
I hope you did not "QUENCHING" hot metal parts while showering your engine bay.

The chance is rare but cracking metal can happen! Usually you will hear "louder noise" beside rattling as the result.

Edit:
One last time, good luck! Keep your fingers crossed.
Msg me if you need more help.

 

Thank you guys for all your help. I just bit the bullet and Opend up the cover, took all the spark plugs out and go and behold there was water in the last three spark plugs. It ran rough for a while but is purring really nice right now. Man I almost SH($* my pants.

 

Maybe try getting it steam cleaned next time. I've even had one problem with that in the past, but mainly good results.

 

Honestly, why risk wetting your engine/messing it up if you aren't showing it at a car show? Sure a clean engine looks nice, but the risk/reward is not worth it.

Anyhow, from previous threads, I believe it took a few days having the car sit in the sun and then everything was fine. I also think the owner replaced the spark plugs.

 

I've needed engines cleaned for a couple of reasons, both when I first purchased used vehicles with well over 100k miles. One had an oil leak somewhere and was a complete mess. The other was just a complete mess. The one with the oil leak was originally diagnosed as having a leaking rear main seal. After I had it steamed cleaned, it turned out to be a missing oil drain plug washer. It was that messy. So I think there are times when it is needed. Personally, I would stick with steam cleaning and not just a stream of water.