Turbo is whistling, down on boost.......
 

1985 300TD {only one T please!} http://i29.photobucket.com/albums/c2...Batmanhead.jpg
At first I thought I had a wheel bearing squealing, but I finally realized it is the turbo whistling during boost. I am also down on boost pressure, from 10.5 to about 5.5 to 6. Car is noticeably slower of course.
I have:
*Removed and inspected boost line from manifold all the way to alda. No leak in line or at connection points. {overboost bypassed}
* Replaced waste gate hose. Had a few cracks in it, but that wasn't the issue apparently.
*Removed air cleaner and with inspection mirror looked for anything visually amiss with the turbo or associated piping.
*Air cleaner U-tube sealing correctly.
*No play in forward impeller inside the turbo.
*I have never messed with waste gate or anything having to do with this.
I don't drive this wagon all the time. I just began to notice this noise, and finally realized what it was. Haven't done anything under the hood prior to this happening.

I would welcome any ideas on a course of action from here.......:confused:

The ARV is at fault. Disconnect the vacuum and plug up the line. Drive around and report back.

Remind me, what exactly is the ARV {air recir. valve?} EGR???

Yes. Air Recirculating Valve. It is that growth on the front housing of the turbo with a vacuum line attached to it. The function is to lower boost pressure so that the exhaust backpressure is higher and more exhaust flows through the EGR.

I tried looking for pic, but don't have one available.

http://i29.photobucket.com/albums/c2...85Stuff006.jpg

There is that evil falic looking device! :eek:
I had put a bb into the vac line to that a couple years ago. Does that have any bearing on this what-so-ever?
Where's a blocking plate when you need it...... :o

The BB should of cut off the vacuum, thus rendering it useless. Try unplugging though, maybe your still getting vacuum in there. Or else the ARV somehow stuck open.

Ask a question, get a correct answer!!! How awesome is that!? :)

OK, gonna need some splaining please. I already had a BB in the upper line to the EGR appendage.
http://i29.photobucket.com/albums/c2...85Stuff006.jpg

So I disconnected this bottom line gong to? and plugged both ends and I have full boost now!! Nice.

http://i29.photobucket.com/albums/c2...Vactoturbo.jpg

But what had happened, and what have I bypassed? This is of course an '85 model with about a million vac lines, and that line comes from a solenoid on the driver's fender over to the above connection point at the turbo area. What exactly is that where the vac line and green T are going to?

And as an awful aside, I sure wish I hadn't slammed my hood down on my phone! :eek::eek: It didn't fair well at all..... :(:(

Vacuum was getting past the BB, the BB was acting like a check valve to keep that leaked vacuum in the ARV and holding it open.

Check the vacuum and wiring diagrams, there is gobs of hoses related to the EGR and ARV that can be safely removed.

Isn't that the second time you've slammed your hood on a phone?:D

Well, the line that had the BB is still intact. {the upper line to the egr}
The one I plugged today was the lower line going to whatever that part of the turbo assy is..........

No, my son slammed the hood of his Mazda 3 onto his 16gig Iphone, and it was sticking halfway out from under the hood but it didn't damage it.
Mine didn't crack the display but cracked the lower buttons. {Samsung fake-Iphone} :o

In Coda's trunk.

:D

Your phone still works, though.

;)

How on earth did you find the time Jimmy?
Been missin' you here.

I have an EGR kit if you want it, just PM me.

Also I can get a pic of my '85s underhood so you can see what to bypass/remove and where.