Whining/high pitch noise after power washing undercarriage

First off, thank you all for your time and wealth of knowledge

I took my 2011 Tacoma (93,000 miles) to the car wash today to clean the under carriage after driving some dirt roads and through very shallow water/mud this weekend. By no means was this excessive off roading or muding but the truck needed to be cleaned. I self sprayed all the tires, wheel wells and under carriage. After the leaving the car wash and driving down the road I started hearing a loud whining/high pitch noise that started around 40-45mph. It will last until around 55-60mph and then will go away. It will continue even when I hit the brakes or put the transmission in neutral. I've let the truck and undercarriage completely dry and it's still making the noise. I did some research and greased all the zerks on my drivetrain. Sprayed the brakes with some brake cleaner. Still no luck. It definitely was not making this loud noise before the wash. Any help or suggestions would be greatly appreciated.

Thanks

 

Did you go through any deep water? High enough to cover the diff and or tanfer case? Also check carrier bearing. Or u joint

 

No. Deepest was only a couple inches. And it didn't start whining until after spraying the undercarriage today to get rid of some of the mud that splashed up.

 

Jack the rear end up(on jack stands) and spin the rear tires. See if you can isolate the noise that way. Check the u joints and carrier bearing

 

Did you spray the alternator?

 

If you sprayed any of the pulleys up front hard, and/or mud or dirty water got up in them, their bearings could be bad. Usually idler pulleys. Is the whine coming from the engine bay? It will whine 24/7 and get worse while driving

 

No I didn’t spray the alternator. it’s only whining between 40-60mph. Hard to troubleshoot because of the speed that it starts whining but it definitely sounds like it’s from somewhere behind the engine bay. Could it be from the drum brakes in the rear?

 

I think the car wash was coincidental not the culprit. The psi on those sprayers is very low.

Is the underbody clean or covered in mud?

Have you played with your U joints and made sure everything is tight?

 

It’s definitely clean for the most part. I’m going to get under it today and make sure everything is tight. Drove the truck to work today which is a short 5 mile drive and didn’t hear a peep. I live in FL and yesterday was a cold damp day so if it was due to water getting somewhere after the wash it would have taken a good bit of time (like overnight) to dry out. I’m not convinced yet though, after work I’m going to drive it for at least 20-30 min and get some highway speeds to see if it comes back. Thanks for the help so far guys!

 

Regease the zerks on your driveline. If you’ve never done that you may have just blasted off what little grease remained.