Could someone please tell me what is this valve for . The linkage is broken , do i need to replace the whole thing or just the linkage. If i don't replace it would it cause any damage to the engine
Many thanks

 

Hi schiu-

Those are the intake manifold linkage arms.
They control a set of flaps that help determine power at higher demand/RPM and are commonly broken due to cheap plastic design.

Several members at AW have replaced them with these gruvenparts.com - Billet / Composite 4.2L V8 Intake Manifold Linkage Arms

 

Thanks jakematic for your quick reply. Is it possible to remove the old plastic arm and replace with the metal one without taking the actuator and the vaccum out

 

I believe so.
It snaps onto the actuator.

Have a look at these two threads - lots of info there:

http://forums.audiworld.com/showthre...ghlight=gruven

http://forums.audiworld.com/showthre...ghlight=gruven

 

Just checked my manifold linkage arms. Both are intact but I have a question about actuation. When revving the engine, the "lower" rod actuates, that is the daiphragm moves the arm. The upper daphragm attempts to move but the arm doesn't move. Should I be able to move the arm manually? I am wondering if the linkage is frozen.

I have been concerned about performance....the advertised 0-60 time is 6.7 seconds. We've clocked ours several times at 8.7 - 9.0 seconds. Wondering if this could be part of the problem?

 

I'm pretty sure you should be able to move them by hand.
It's possible the system is "frozen".

IIRC one is for low speed torque and the other is for higher RPM.

Never had the issue personally, but read a lot about it and recommended the Gruven's to a guy in Australia because they were a lot cheaper for him.

 

Thanks for your reply jakematic. I have removed the broken linkage , i can move the actuator by hand it is hard to move the arm but i don't feel any resistant . is it suppose to be like that as the Gruven's menu suggest removing the actuator to clean and lubricate which i don't want to . How do i know that the actuator need servicing. By the way both valves stay deflated even when the engine was switched off , it wasn't like that before i remove the broken linkage and spray lubricant onto the actuator. The car was stationary when i carried out the above procedure but i did rev the engine to see whether the valves still collapse . Is it suppose to be like that ?

 

Thought about it last night.......I'm going to reomve both arms and check the arm that does move when the engine is revving to see how "free" it is and compare it to the one which didn't move to see if it moves at all and lubricate both.

I am going to order the arms from Gruven's also.

Thanks for the input!

 

It's been 10 hours since i removed the linkage but the valves still collapse and i can't even open the engine oil filler cap . I can pull out the dipstick but it will not release the pressure.If this carry on will it damage the engine , what can i do now please help

 

Schiu,

When you say the "valve is still collapsed" are you referring to the rubber diaphragm that actuates the arm?

If so, the diaphragm's normal position is extended and you can pull it out to the extended position by hand and it should stay there; that is the position it should be in with engine off. Vacuum collapses the diaphragm to actuate the arm.