random Engine noise after pressure wash

After power washing and starting truck there was a low pulsing humming type noise from front end, best way i can describe it. Pump noise? Went away after about a minute or two.
I remember the same thing had happened last time i washed my truck there. Wasn't washing engine or anything but I remember last time thinking it probably had something to do with me trying to get bugs off bumper. So overspray through grill on radiator/ engine. I remember not really worrying about it but today had just cleaned maf/tb so would have been stressing if it hadn't occurred before.
Anyway just wondering what you guys think. Obviously from getting something wet. Trying to educate myself some more. Thanks

 

No thoughts?

 

I would not pressure wash your engine bay. Use regular ol water pressure only.

I have not had an issue with washing/detailing my engine bay. Have not had any noises come from it.

Get a bug mit or sponge for your bumper, don't attempt to pressure wash it off, not unless you want your paint to come with it one day. Water is to rinse not clean. Also use a sealer on the front end to prevent bugs from sticking so bad. They'll fall off better. I use Chemical Guys Jet Seal but there are many to pick from. My sealer lasts 6 months but I normally have to reapply an extra time in the summer because of the pesky bug guts

 

maybe a wet belt

 

Ok got wet belt from other forum so might be it. Had. Ever heard of that before. Wasn't washing engine bay. Just a car wash sprayer not really a pressure washer. Doesnt even hurt hand