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Loosing power/boost after driving after an hour or more
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Fasteddie313  



Joined: 29 Sep 2013
Posts: 1853
Location: MI

PostPosted: Sun Jul 14, 2019 4:37 am    Post subject: Reply with quote

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/954175-wastegate-valve-clearance.html

[QUOTE=OSI930;9599414]The valve measures 0.390" and the valve guide is 0.393". Both of the parts are new.[/QUOTE]

Still doesn't really answer the question of how much is too much but .003 clearance on the new parts is really really close so I'd think that if it flops around in there it might b too much..

Also interesting..
[QUOTE=reclino;9617404]Analysis of the valve using X-ray fluorescence shows that it is primarily Inconel, 73% Nickel, 19% Chromium, 2% Titanium 1.5% aluminum (could be surface contaminant) 1.5% iron...... Looking closely at the new valve OSI930 sent me shows evidence of a weld line at the seat area, I suspect its Stellite welded but will wait for test results. The new guide looks very much like copper, and I suspect its beryllium copper, but have not tested it yet. I work slow but results are worth the wait.
David[/QUOTE]

[QUOTE=dap930;9696297]David,

It is good that you found a shop that will machine beryllium copper. I assume the shop knows the hazards involved with machining this material. When I worked at a naval shipyard, the engineering department had to provide special instructions so the machinist were not exposed to its vapors or dust.[/QUOTE]

So I guess don't go grinding on that valve guide..
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chuck21401  



Joined: 20 Feb 2005
Posts: 189
Location: Annapolis, MD

PostPosted: Mon Jul 15, 2019 8:42 am    Post subject: WG is out! Reply with quote

I removed the waste gate today. Not as bad as I thought it would be, but it did take a while.

I took a bunch of pictures to document the process and will post those next.

Can't really tell much from the pictures below of the WG...but between the hot/cold side the gasket seemed a bit gooey. Seem like if there was a big leak there it would look different.

Next step will be to disassemble the WG and check it out. I was thinking about criss-crossing some straps across the top to prevent the spring from going flying.









[/img]


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Last edited by chuck21401 on Mon Jul 15, 2019 10:04 am; edited 1 time in total
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chuck21401  



Joined: 20 Feb 2005
Posts: 189
Location: Annapolis, MD

PostPosted: Mon Jul 15, 2019 8:59 am    Post subject: Reply with quote

I had hoped to start this project on Saturday but wasn't happy with how I had lifted the car off the ground...it just wasn't high enough. So I did more reading and came up with the following.

Jackstands and ramps in the rear. The ramps are the back up and not supporting weight.



Jackstands in the front with my floor jack as a back up. Again the ramps are there just in case and not supporting any weight.



With sufficient room to work, I was ready to go.
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Fasteddie313  



Joined: 29 Sep 2013
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Location: MI

PostPosted: Mon Jul 15, 2019 9:03 am    Post subject: Reply with quote

If some gooey sticky stuff from that gasket got on the shaft of the valve in there I could see that causing it to stick.. ?? maybe
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chuck21401  



Joined: 20 Feb 2005
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Location: Annapolis, MD

PostPosted: Mon Jul 15, 2019 9:06 am    Post subject: Reply with quote

Step 1 - Remove starter

The starter was relatively easy -- except it appeared to be covered in fluid. I think the clutch slave cylinder is going bad. Ugh.



The two big nuts are 19mm. I disconnected the wires that I could see and pulled down the starter...but surprise...there is another wire there requiring a phillips head screw driver to remove. So be ready for that!




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chuck21401  



Joined: 20 Feb 2005
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PostPosted: Mon Jul 15, 2019 9:12 am    Post subject: Reply with quote

Step 2

I did this out of order. The book says "detach and remove bypass line between exhaust manifold and waste gate."

I wasn't clear that meant the J pipe. I disconnected these parts:





And then I realized they were talking about the j pipe. The good news is that the nuts too little effort to remove.
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chuck21401  



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PostPosted: Mon Jul 15, 2019 9:17 am    Post subject: Reply with quote

Step 3 - remove J pipe

These nuts were easy to access and not super tight.



Used a long extension to loosen the nuts that connect the j pipe to the exhaust manifold.



Here's picture with the j pipe removed. Makes you think that the WG is ready to drop. Nope. Not yet.


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chuck21401  



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PostPosted: Mon Jul 15, 2019 9:31 am    Post subject: Reply with quote

Step 4

Loosen final muffler bracket and strap remove rear muffler.

OK, this is where I needed some penetrating oil. Pep boys didn't have a small can of PB blaster, so I bought CRC Feeze-Off and that worked very well.







The Haynes manual doesn't adequately address gravity. I rigged up some bungee cords to prevent the muffler from falling off as I undid the strap.



Pic with muffler removed. I am surprised to see how small the transmission is on this car. CV boots in good shape. Also realizing that this car has a rear sway bar. The bushings for the swap bar look tired so that is a future project.




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chuck21401  



Joined: 20 Feb 2005
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Location: Annapolis, MD

PostPosted: Mon Jul 15, 2019 9:33 am    Post subject: Reply with quote

Step 5

Loosen heat shield over bypass line. Hmmm can't get to that yet.

Step 6

Loosen pipe clamp at bypass line. OK, did that already.
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chuck21401  



Joined: 20 Feb 2005
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Location: Annapolis, MD

PostPosted: Mon Jul 15, 2019 9:38 am    Post subject: Reply with quote

Step 7

Detach holder and control line at wastegate and remove entire exhaust line with wastegate.

What the heck? Need to unpack that into at least three more steps.

Basically the exhaust from the turbo to the final muffler has to come down next...and that includes the catalytic converter. That's a lot of pipe...and heavy. So I rigged up my bungee cords again.

Here is the flange that connects to the final muffler. Tied the bungee to the exhaust hanger.




Upfront, wrapped the other one around the pipe and attached it where I could.


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chuck21401  



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Location: Annapolis, MD

PostPosted: Mon Jul 15, 2019 9:46 am    Post subject: Reply with quote

Step 7, Part II

At point there are three points holding the exhaust to the car:

1. four bolts at turbo
2. bracket under WG
3. Exhaust hanger

This car has an A/F meter, so had to remove that first. As you can see, it has a white film on it, what does that mean?



The nuts on the turbo came off fairly easily, especially with a couple of shots of CRC.



Shoot. One of the studs came out. Which side goes in the turbo? The short side?



Here you can see which stud came out.


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chuck21401  



Joined: 20 Feb 2005
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Location: Annapolis, MD

PostPosted: Mon Jul 15, 2019 9:53 am    Post subject: Reply with quote

Step 7, Part III

With the exhaust free from the turbo, only two brackets remained.

Here is the bracket under the WG



Here is the other bracket...and reminder about gravity....remove all of these nuts and the exhaust will come down in a hurry!


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Last edited by chuck21401 on Mon Jul 15, 2019 10:11 am; edited 1 time in total
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chuck21401  



Joined: 20 Feb 2005
Posts: 189
Location: Annapolis, MD

PostPosted: Mon Jul 15, 2019 10:00 am    Post subject: Reply with quote

Step 7

Remove wastegate. Finally!

With the exhaut out of the way it's much easier to remove the heat shield - four phillps head screws.

The WG is held into place with two nuts. This thing is heavy so I tied a bungee around it to slow its descent.



You also have to remove the banjo bolt for the boost control line.

And that's all she wrote. Here are the various parts I had to remove with help from Haynes. The exhaust is heavy and glad I didn't drop it on my head.


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chuck21401  



Joined: 20 Feb 2005
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Location: Annapolis, MD

PostPosted: Tue Jul 16, 2019 5:23 am    Post subject: Reply with quote

Fasteddie313 wrote:
So I guess don't go grinding on that valve guide..


I was re-reading that thread...the following post says:

"Read what I posted again, material will be berillium copper REPLACEMENT. It will be made of a precipitate hardened copper nickle silicone alloy. There is no need to use berillium copper for this type part anymore. Trying to hone one yourself to fit would be toxic."

So that's good...
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chuck21401  



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PostPosted: Tue Jul 16, 2019 11:57 am    Post subject: Reply with quote

So I'm curious to know what is going on here...but not quite ready to disassemble the WG until I figure out how to prevent that big spring from jumping out.

I connected my extra boost control line to the WG. Then I connected my battery powered Ryobi portable air compressor to the other end. I was thinking I could build some pressure to see the valve open....no such luck. The WG wouldn't hold any pressure. I found that the air was leaking from the top vent. Shoot...so that means torn membrane?

Here is the other part. I figured that I could push down on the valve to get it to open (despite the big spring holding it shut). I tried several times...not such luck. Added some CRC freeze...more pushing...and it broke loose. Not easy to push in, but it did go.

So next step will be to open up the WG and verify that membrane is torn. But what would cause the valve to stick if it was indeed stuck?


Still curious to check out the play in the valve guide but that theory is a bit diminished with today's findings.
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