Hey guys,

What happens is, when you apply the break while in drive the truck will start to shake. It doesn't try to die it just shakes. When you shift to neutral it goes away instantly. Also it doesn't do this in park, or even all of the time when in gear, just enough to be annoying.

Also when you shut the truck down there is this buzzing/ farting type noise and i have narrowed it down to the driver side just under the edge of the motor cover towards the front and there are two vaccume lines that go into it and one of them goes to the egr valve. I don't know what the part is called but im guessing it is part of the problem?

EDIT: just found that part on autozone's website and it appears to be the egr vacuum solenoid. Also, there doesn't seem to be any vacuum in the line going to the egr valve. Is there supposed to be?

As always any advice would be appreciated.

specs: 97 4.6 4x4 auto

 

I'll take a wild guess at this.

I think that is about the same area that the main vac line for the brake booster connects to the manifold. Take a very close look at the booster line for cracks, splits, or chaffing.

I would say you have a vac leak that is part of the brake system someplace, could also be the check valve on the power booster.

Remember this is just a guess. Do you have a check engine light on? If so what are the exact codes.

Good luck.

 

Nope, no check engine light. haha i wish it was that simple! then i might have something to go on. Thanks for the reply ill have to go take a look.

 

Sounds like torque converter problems IMO.
That's normal, so you can relax there. -They can all play a tune after shut down at some point. It's just the EVR relieving itself (true that) and expelling it's store of air. And that's correct, -it is a solenoid. One of many. So no worries, sometimes they make noise, other times they don't, - doesn't effect operation either way.
In short, -yes and no lol. That solenoid (EVR) is PCM controlled to open the EGR valve @ cruising speeds. So, vacuum only passes thru the valve upon command (program) and for just a short time while cruising the e-way or similar circumstance.. You should always have vacuum at the solenoid (white line normally), but not from the solenoid (green line).

 

Could be several causes or a combination of two.
Sounds like the EVR is not letting vacuum out of the EGR and keeping it open a small amount. That will cause engine roughness. On decelleration the vacuum is the highest so will aggravate it the most at that time.
If the idle is normal in Park and/or Neutral, the IAC should be good..
Lastly if the converter one way clutch diode is locked up it will load the motor as you come to a stop.
My bet is the EVR.
It has a filter under the round cap that lets air back into the EGR.
This filter gets plugged.
If the EVR sticks partially open it will allow engine vacuum to open the EGR when it's not supposed to.
If the EGR cannot close or let the vacuum out, noises can be heard as it bleeds down after engine shut off.
I would remove the EVR and clean and service the filter and inside operation with cleaner.
Good luck.

 

Actually, by design, it maintains vacuum. Even at zero duty cycle (no voltage) some vacuum will still pass the EVR, (around .02-.03 hg) but this is not enough to overcome the spring pressure.
I'll take that bet.
Iduno, Fords been using the same EVR's pre- 10th generation, they're reliable.
They do get noisy. However, the bleed down noise ISN'T filter related (believe it or not). They can plug from dirt/contaminants or shrivel up and plug. That said, vacuum bleed out isn't effected, - not very much anyway. If you pull the filter and test a noisy EVR without, it will still remain noisy. - Regardless, the solenoid works as it should. Replacing the complete EVR usually stops the noise, -for awhile anyway.

I know what your saying and you may be right, it sounds possible. However, I haven't heard of one going bad like that in the past, have you?