So I am trying to help my friend get his Turbo II back on the road but, we have run into a problem. In the picture I have circled what is called a switching valve that appears to operate off of a vacuum (which I am assuming comes from the intake manifold). We have removed all the emissions related equipment and installed the appropriate block off plates.

Does that metal line bolt onto the valve with a banjo bolt?
What does that valve do?
Where does that metal line go to?

 

My T2 knowledge is limited, but i believe that is the vacuum line for the wastegate, which is very important

Edit: i take that back, a vacuum line wouldn't have a banjo style bolt, next guesstimate is the oil feed

 

I think your first guess is more accurate. I know it is not the oil feed line that goes into the actual turbo assembly. Why would mazda use a metal line as a vacuum line for the wastegate? Am I missing something?

 

twin scroll actuator.S4 TII's had them.

 

bingo.

 

Thanks guys,

Where can this bolt be bought that secures the metal line to the actuator? Does anyone have a part number? Can someone confirm it is a banjo bolt?

Where does this metal tie into on the intake side? Can it be any vacuum port?

 

twin scroll solenoid in the emissions rack under oil filler neck. cant remember off the top of my head which one. and yes banjo bolt.

 

you said you removed all the emissions stuff so did you do the rats nest delete you would have to leave one of the solenoids that controls the twin scroll actuator (the one you circled) it doesn't just go to a intake vacuum line iirc or else it will take the turbo longer to spool at lower rpms if its left off

 

The twin scroll is more performance oriented than it is for reducing co or emissions. I would rather keep it to give you quicker pick up in the turbo than without it. It's your car though, you may like to just have the turbo on full at all times.

 

Anyone know what size the bolt is? Mine broke and in the process of trying to get the engine back in and running misplaced the broken bolt. Yes i've searched and yes i've been doing alot of swearing every time a thread has info about the twin scroll actuator w/o the bolt size. Grrrr!

 

Kept searching and found the size in a fore sale thread of all places. M8 x 1.25 banjo bolt. Used on some small bikes too, best bet is ebay or a uk supplier on amazon.
Cheers

 

Ditto on the M8x1.25. I think Mazda used similar bolts on the OMP at the pump, but don't quote me on that. It's probably a little too long for the twin-scroll actuator. If you need to replace it, go with Amazon, unless you're a proficient junkyard scavenger. Weirdly enough, McMaster-Carr, Belmetric, Grainger, Copper State, O'Reillys, Autozone, NAPA, and Ace Hardware all don't have M8x1.25 banjo bolts. First time I've found a bolt that's stumped all of them.

Also, don't forget your crush washers. I used thread sealant for good measure, although it isn't a big deal.

For future reference on the plumbing: the metal line tucks against the insulator, runs around the back of the turbo under the downpipe/precat and ends by the EGR. It joins the rest of the rats nest there, where it follows the main ribbon around the back of the engine, behind the lift bracket, and plumbs into the solenoid, which is the one at the furthest end to the front of the engine. I did a rough mark up of an FSM diagram, though it's too grainy for me to trace back to the solenoid. Actuator marked in red, hard line marked in blue, solenoid marked in green.



I'll be tearing the turbo out of my car this weekend (again) so I can verify the exact length of the banjo bolt and what length will fit.