dieseltwitch

find a new mechanic! if he doesn't know there is a vacuum system... hes an idiot!

prochjw28

So... got back from Ford today, and they said both IWE's were bad and replaced them both. Took truck onto highway right away and made the grinding noise still.
My question is: Would the actuators just being bad make the noise by themselves or is that a result of a vacuum leak somewhere along the line?
Basically should Ford tech have checked the lines for a leak or tested the solenoid to being bad too? They shop and service techs were closed when I went to pick it up so couldn't call and ask them right away.

Thanks for any replies.

VTX1800N1

If the IWEs are new, you have a vacuum leak or bad check valves, and yes they should have checked.

prochjw28

The dealership said they did check the vacuum lines and only leak they had was at the IWE's. The service advisor said it might be wheel bearings or hub but that they looked at hubs when they replaced IWE and would have seen if they were bad. Thoughts on that or what else to look at?

Would you think they did't check all the check valves and maybe one in the middle is bad because the first and last one would hold the pressure? Just a thought.

Jet A-1

I had a check valve that was blocked with dirt and was easy to check (you could blow through it in both directions..LOL) - located near the battery, easy to change out... The vacuum solenoid on the firewall, also near the battery is another problem area - prone to water infiltration if memory serves me correctly.

dutchford

I have a 2009 F-150 FX4 had this same problem, started with actuator replacement, WHICH is something you should seriously considering checking out and making sure they don't need to be replaced because of the grinding which is the IWE Actuators partially engaging. I then moved on to the solenoid, ended up replacing because they are fairly inexpensive around 30 bucks, still didn't fix it, now I'm in the process of checking vacuum lines. Little knowledge on the on the system, basically what's happening is the system has a vac reservoir which stores a certain amount of pressure which is held by a check valve. The reason why the noise happens when under load or at higher speeds or sometimes at quick acceleration is because the system has plenty of vacuum because the hole in the vacuum lines is probably a pin hole size, but when you apply more acceleration it actually lessens the pressure from the manifold because its diverting elsewhere and not towards the 4x4 vac system which brings it down accompanied with the hole to a level that is not enough hold the actuators away from the cv axles which is below i believe somewhere around 5 pounds of pressure.

Steve Osborne

sister bought an 07 5.4.. same with hers idle/cruising no grind.. accelerate and it would grind.. they replaced the iwe's and actuator .. still did it.. went and looked at it .. you could hear the leak by the battery.. the plastic reservoir had a split on the seam. may wanna check it..

dutchford

little update pinned it down to a stupid little check valve haven't the noise yet hopefully we're good.

VTX1800N1

Exactly what I said it would be....

60DRB

VTX1800N1

"Or, you could follow the complete how to diagnostic I posted...."

You crack me up.