icefalls Posted July 21, 2004 Report Posted July 21, 2004 I recently found that this particular vacuum hose had perished and cracked right where it joins the larger hose, and had it replaced yesterday, but I was wondering what its function was.The one I'm talking about is the nice shiny new one in the middle of the picture below:This other picture show the other end of the line. It is the middle one of the three. The other two hook up to the turbocharger:What does this hose do? It seems like the one discussed in recent topics, to do with PCV operation, but that doesn't seem right here, given that the other end hooks up somewhere different.Can anyone shed some light on this for me?
elabuschagne Posted July 21, 2004 Report Posted July 21, 2004 I recently found that this particular vacuum hose had perished and cracked right where it joins the larger hose, and had it replaced yesterday, but I was wondering what its function was.The one I'm talking about is the nice shiny new one in the middle of the picture below:This other picture show the other end of the line. It is the middle one of the three. The other two hook up to the turbocharger:What does this hose do? It seems like the one discussed in recent topics, to do with PCV operation, but that doesn't seem right here, given that the other end hooks up somewhere different.Can anyone shed some light on this for me?←I am also interested in this hose's function, particularly the plug on the opposite side of that hose. I discovered that plug the other day in my '95 T5 850 Wagon and saw that it was NOT plugged in. I plugged it right back in, but could feel no difference (other than "wishful feelings").Etienne.
Geevs Posted July 21, 2004 Report Posted July 21, 2004 Hi,In the picture, I noticed that the big hose (coming from the MAF) is pretty oiled and greased up below. Is oil leaking somewhere or is this normal? I have the same greased patch in the same area.Thanks,Geevs
Bay13 Posted July 21, 2004 Report Posted July 21, 2004 That area, the new hose and the bigger hose and the electricial connector is the PCV system for the most part for the turbos.(it's like the flame trap area on a non turbo)The big hose is crankcase fumes from the PCV box under the intake manifold, the smaller hose, (the new one in the picture) is vacuum to help pull the fumes from the larger hose into the intake, it usually hooks up behing the power steering pump on the intake manifold. The electricial connection is for the heater grid thats on the connector to help warm the air or keep it warm, colder air would cause the oily mist to condense and you would have even more oil film on the inside of our turbo pipes.
icefalls Posted July 21, 2004 Author Report Posted July 21, 2004 That area, the new hose and the bigger hose and the electricial connector is the PCV system for the most part for the turbos.(it's like the flame trap area on a non turbo)The big hose is crankcase fumes from the PCV box under the intake manifold, the smaller hose, (the new one in the picture) is vacuum to help pull the fumes from the larger hose into the intake, it usually hooks up behing the power steering pump on the intake manifold.Thanks for that explanation Rich. It's interesting that the vacuum hose is hooked up differently in my car. And to tell you the truth, I've searched and searched for that connection on the intake manifold and never found it!In the picture, I noticed that the big hose (coming from the MAF) is pretty oiled and greased up below. Is oil leaking somewhere or is this normal? I have the same greased patch in the same area.No, that isn't normal! But hopefully replacing the oil filler gasket should take care of that. There was plenty of oil under the spark plug cover too.
Bay13 Posted July 21, 2004 Report Posted July 21, 2004 on some cars that don't hook in behind the power steering pump, it's hooked in with the vacuum tower by the throttle linkage.
icefalls Posted July 22, 2004 Author Report Posted July 22, 2004 The plot thickens!! Following Rich's comments, I checked up a few pictures on my alldatadiy.com account, and I'm now pretty sure that a few things are hooked up incorrectly, but I need someone to confirm this for me before start randomly plugging and unplugging hoses!The other end of the hose Rich identified as the PCV vacuum hose is plugged into this part. Isn't this the turbocharger control valve? The PCV hose is the one in the middle:In the picture below, the hose on the right (with the yellow tape) is the rightmost hose connecting to the TC control valve (picture above). The hose in the middle below (you can't see the end in the picture), is the one connecting to the TC control valve on the left.The hose on the left in the picture above connects to the side of the intake manifold. The picture below shows it connecting underneath a larger hose:I couldn't find the vacuum tree Rich mentioned, but it seems to me that the PCV hose should connect to the manifold, and that the other hose on the turbocharger should connect to the TC control valve. Can anyone clear this up?
elabuschagne Posted July 22, 2004 Report Posted July 22, 2004 The other end of the hose Rich identified as the PCV vacuum hose is plugged into this part. Isn't this the turbocharger control valve? The PCV hose is the one in the middle:I agree, that doesn't sound right, isn't that supposed to go to the inlet manifold/vacuum tree? I'll have a look at my car tonight and see what's going on there.I couldn't find the vacuum tree Rich mentioned, but it seems to me that the PCV hose should connect to manifold, and that other hose on the turbocharger should connect to the TC control valve. Can anyone clear this up?←The vacuum tree is hidden below a black cover that screws on top of the throttle body assembly. Take off that cover (one screw) and you'll see a vertical pipe thingy with vacuum lines coming out horizontally from it (some of the connections are blanked off). The throttle body assembly is the one attaching to the right of the inlet manifold.The black cover cannot be seen properly in the image below as the image was taken at night and is quite dark. There is a white sticker (that I have put there) on my car's throttle body cover. The white sticker can be seen in the image in the bottom right hand corner (it's the horizontal white line running to the edge of the image). The retaining screw is also visible above the white sticker as a blurry grey spot right above it. Right below that cover is the "vacuum tree"
Stamperman Posted July 23, 2004 Report Posted July 23, 2004 That area, the new hose and the bigger hose and the electricial connector is the PCV system for the most part for the turbos.(it's like the flame trap area on a non turbo)The big hose is crankcase fumes from the PCV box under the intake manifold, the smaller hose, (the new one in the picture) is vacuum to help pull the fumes from the larger hose into the intake, it usually hooks up behing the power steering pump on the intake manifold. The electricial connection is for the heater grid thats on the connector to help warm the air or keep it warm, colder air would cause the oily mist to condense and you would have even more oil film on the inside of our turbo pipes.←Speaking of which my 94 turbo wagon doesn't have the vacuum elbow behind the power steering pump. It does have the big piece of bent metal tubing that runs between the cams. Did they add that elbow when they quit using that piece?
Bay13 Posted July 23, 2004 Report Posted July 23, 2004 Speaking of which my 94 turbo wagon doesn't have the vacuum elbow behind the power steering pump. It does have the big piece of bent metal tubing that runs between the cams. Did they add that elbow when they quit using that piece? 1994 was the first year for the FWD turbo, so thats how they did it then, and it's changed along the way. The thought was to keep the vacuum warm.
icefalls Posted July 23, 2004 Author Report Posted July 23, 2004 So are the three hoses coming from my turbo hooked up correctly? Or should all three go to the boost control valve?
Bay13 Posted July 23, 2004 Report Posted July 23, 2004 Nope I don't think they are hooked up correctly, the turbo control valve has three color hoses, red, blue, and yellow. The hose isn't all that color there are just markings on them. I'd have to look at mine to tell you how it's suppose to be hooked up. but in your picture the center, blue dot, I know doesn't go to where you say it does. The red is manifold pressure signal, the blue is bleed, and the yellow is is waste gate servo signal. but like I said, not much ever goes wrong with these at the dealer so I'd have to look.
icefalls Posted July 23, 2004 Author Report Posted July 23, 2004 but like I said, not much ever goes wrong with these at the dealer so I'd have to look.That's why I want to be certain of the correct configuration before asking questions at the mechanic. I've recently moved, so I can get my new mechanic to check the configuration, but it all seems a little counter-intuitive to me to have all but one of the hoses from the turbo connecting to the turbo control valve.As it is, I don't think I get absolutely full boost. My gauge only ever goes up to a third into the white section, and it takes a while to get there.Thanks for everyone's help so far! Its all so much more confusing for me with the multitude of differences between models! Just to clarify, my 850 was built in August 1993.
AutoX47 Posted July 23, 2004 Report Posted July 23, 2004 blue normally goes to the nipple on the intake hose from the MAF to the turbo. It has to be before the turbo to work correctly or you will only make as much boost as the wastegate is set atAlso: Rich do you know offhand what the inner diameter of the elbow at the manifold is?
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