When I turned my truck off the other day I noticed a buzzing noise coming from under the hood. I followed the sound and found that the TAD/TAB solenoids and the coil were vibrating. I put my hand on the solenoids and found that the vibration was coming from the solenoids that has vacuum lines going to the EGR. It was buzzing and vibrating for about 2 minutes after the motor was shut off.

I guess this means that the part is bad. But is it really a solenoid and what does it do? I don't understand why it would be buzzing like that. Any ideas would be helpful.

 

It's the solenoid that activates the EGR valve. If you did an Error code scan you would get a #33 code for EGR not closing, or something similar, courtesy of the EVP sensor. The solenoid is essentially a valve itself. Vac is probably flowing through the normally closed solenoid, as the system de-energizes.

 

I did get that code the last time I had codes read. Recently I took the EGR off and put a block off plate in it's place and the problem remained. What affect would this solenoid have on the motor without the EGR being connected (I have the line that went to the EVP plugged)?

 

I really don't deal w/ engines that have been altered. Hard enough to figure them out when everything's there. I'll guess nothing, & the code's courtesy if the EVP sensor. Good luck w/ that. Here's a link that describes what your EGR used to do.http://fordfuelinjection.com/?p=64