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Hi all, last year I discovered my HG was leaking, at least it looked like it (not smoking exhaust but stuttered at startup and coolant coming from the turbo flanges) and per recommendations from this forum I stopped driving the car till I had time to dig into it. Now’s the time! I pulled the head and not sure if it was the HG or intake gasket. I’m no expert but the good news is the head looks great, no pitting I can see except some light surface corrosion around the intake coolant passages. I have some decisions to make and some questions and would like your input.

It’s a 1993 900 vert turbo 5 sp with about 135k. My goal is for a reliable, fun car for commuting and running around. Not looking for big hp but may want some minor power upgrades in the future. Here are some issues I’m trying to sort out:
1. the head has not been touched, should I resurface? I want to but am concerned with a machine shop messing it up, worth the risk? I would like to have the flatness verified. I don’t plan to remove the valves or replace the valve seals. If I have the head resurfaced should I have them pull the valves and replace the seals? Should I be concerned with hardness if there is no evidence of corrosion?
2. I ordered SAAB head bolts. The new ones came with washers but the ones I removed did not have them, do I use the washers? Do I lube the threads and bolt head? I read SAAB lubed The bolts with Moly 100 but I’ve read different ways, should I lightly oil the threads and head? I ordered thread chasers to clean the threads.
3. when I set the engine to TDC lining up the cam marks the flywheel 0 degree mark was 3 teeth past the timing line on the plate. This seems way off but the #1 piston does look to be at TDC. Should I be concerned? Also, I read an article that said on reassembly to rotate the engine away from TDC because the lifters could be overfilled with oil and open the valves that should be shut, is this common?
4. Turbo: no play in any direction but does leak oil into intake. Posts say this not unusual so I don’t plan to replace or have it rebuilt now. I do have to have one broken stud removed. One question - I would like to verify the wastegate is working But haven’t found how to test. I assume you can apply pressure to the diaphragm and watch it open but not sure what pressure, anyone know?
Other than that, the rear seal leaks but the clutch looks like it have plenty of life left (4+ mm at TO bearing) so don’t want to dive into that yet, maybe next year. Also, the timing chain tensioner is at 11.4 mm so I do plan to replace it ( guides look good).
Sorry for the long post but I’m still pretty new to SAABs and appreciate your comments and suggestions.
Thanks, Pat
 

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Can't help much with most of your questions, but having just done a head rebuild and gasket last spring, I will say it's easy enough to lap the valves and replace the stem seals. The old seals were rock hard on my car, and new ones are cheap and easy to install. Lapping the valves will improve sealing, and it basically costs nothing other than time. I see no reason not to do both while you have the head off.
 

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Discussion Starter #3
Thanks for your reply, I have not lapped valves before and read a post where they had trouble with removing the old seals so was shying away from doing it but I’ll check my seals when I remove the tappets and look into lapping the valves. Cheers
 

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1. Do not resurface unless absolutely necessary. It's not done as a matter of course, only to correct a flatness problem
2. All bolts go in dry except head bolts which require a light film of oil unless the head bolts are TTY. So, you need to know which bolts you got - my guess is that they are the new style ones... check the pn - if they are specified for 9-3 and 9-5, then they are TTY and go in dry. Otherwise, light oil
3. Flywheel is lined up to the plastic clutch cover, not a feature on the motor.
4. I don't think there is a spec for the wastegate actuator.... if it stays closed to 5 or 6 psi it's good enough for base boost, so you're fine.
 

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Discussion Starter #5
Thanks for the advice! Looks like you are right, the bolts are the ones eEuro sells as genuine SAAB, says they are good for the 9-3 & 9-5 as well as the 900 so I’ll install them dry. I assume I use the washers that came with them. Nice to hear about the timing marks, the drawing in Bentley manual doesn’t match my marks at all but my mark does look like the picture 3.1 in Haynes except mine doesn’t match up. I’ll refit my plastic cover and see how it lines up.

BTW, I want to mention that most of my exhaust studs were stuck pretty good. Thought I’d have to have a machine shop remove them but I bought the PT stud remover and it worked great! Removed them all easily. Did mark them up but I’m replacing them anyway. I did break one turbo bolt off, have to have that one removed. Thanks again!
 

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Definitely replace the studs, and you can/should replace the nuts as well. Since the '80s we've learned that copper coated steel is the secret sauce for exhaust hardware. You can buy them from a variety of places (like Ford and VW) as well as atpturbo. One time I randomly got some when ordering Saab parts from eeuroparts, but generally I've gotten regular steel nuts from them.
 

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Definitely replace the studs, and you can/should replace the nuts as well. Since the '80s we've learned that copper coated steel is the secret sauce for exhaust hardware. You can buy them from a variety of places (like Ford and VW) as well as atpturbo. One time I randomly got some when ordering Saab parts from eeuroparts, but generally I've gotten regular steel nuts from them.
Nickle anti-seize works the best. Copper anti-seize should never be used on header fasteners due to heat bonding. It is fine for the other stuff since temps are lower. Make sure you have the proper torque spec for those dry TTY head bolts. If not you might under-torque them. If it were mine I would pull the valve train and install new stem seals at the least. Get a seal puller, it will make removal easier. Don't forget to soak the buckets, upside down, in oil before you are ready to reinstall and start it up. Dry lifters can get stuck.
 

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Discussion Starter #9
Thanks again guys! ATPTurbo looks like a good source, I haven’t used copper coated nuts, will order them! Looks like they have the nuts for the turbo/manifold bolts (don’t know if the 1.5 pitch is correct, will verify).
I also did not know about the copper anti-seize, good advice. I use Permatex stuff, doesn’t say if is Nickle but is rated for 1,600F and silver colored so probably so. So I won’t use anti-seize on the exhaust studs where the nuts go but would you use it on the part of the stud going into the head? Would think so.
I plan to verify my torque wrench is accurate and use an angle gauge for the final turn. Using Bentley manual for torque specs. When I loosened the head bolts I was surprised how easy they were to loosen, same with the exhaust and intake manifold nuts, all three looked like were leaking some.
Cheers!
 

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I always use silver/nickle paste on all header studs, especially on alum heads. For steel threading into aluminum you should use silver anti-seize which is typically nickle powder. The copper stuff is good for steel into steel as long as it does not exceed like 1500F. The copper plated nuts are different in the fact that the copper is already ion bonded and heat treated. The issue with the paste is causing bonding between dissimilar metals at high temps. Copper ions are used for plating and bonding dissimilar metals in the metalurgy industry.
 

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I like antiseize on the studs into the head - because there is no torque to be affected there is no risk, and it's never bad if the studs have an easier time coming out of the head. Antiseize on the nuts DOES affect torque values, and that can result in overtightening and future problems. The copper nuts will come off easy in the future even without antiseize. It's win-win.

IIRC the c900 studs are M8 x 1.25 - atpturbo carries them, and I'm pretty sure you can get them from Ford and VW dealers too. It's more or less the de facto thread size for small engine exhaust manifolds. ;)
 

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Discussion Starter #12
Great information! I have a stud kit that includes the nuts but will be ordering the copper coated nuts as suggested, also for the turbo to manifold bolts. Will use the anti-seize on the manifold studs into the heads. Spent time cleaning flange faces, man does that eat time! I do have some minor corrosion on the intake manifold and mating head areas around the coolant passages, hopefully the gasket can seal them.
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Would it hurt to hone the flange with a long block and paper? My first SAAB engine so still learning. I usually flatten all flanges when I rebuild an engine unless it causes mating issues.
 

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Ah, gotcha. If I'm just replacing manifolds, I usually run a very large sanding block and fine paper over the flanges just to clean them up. I'm sure it happens, but I've never had one not been flat... I just want to get any remaining gasket & corrosion off.
 

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You said the head bolts where not hard to remove...sounds to me like they weren't turned the last 90. I have seen heads bolts with and with out washers installed so it won't matter. My standard process is to remove all the valves and hot tank the head. Then I remove the old guides and install new. I use glass beads in blasting cabinet and blast the valves to clean them making sure to thoroughly clean after. With a small drop of engine oil on the stem I reinsert the valve with a bit of valve grinding compound on it and grind till it seats well. I tried the suction cup tool but wound up just making a tool. I took a section of round bar and shoved some air hose on the end. I slip the air hose over the end of the valve stem and roll the bar between my hands. To do this I have to slide the head over my work bench but it works for me. The hellish part is getting the small keepers back in. I use small tools/ magnets and petroleum jelly to help me get those buggers in while a "C" clamp tool compresses everything. After putting the head back on and torquing it down and remember the 2 bolts under the head by the fire wall, I oil up everything and reinstall. With the black plastic cover popped off clutch housing I time the engine to the raised line on end plate under start motor bolt which can be seen through cut out in black plastic if you can't get it off. It can be helpful to place your valve cover upside down, place new gasket in and put wax paper over and place something flat and heavy on it to help it form to the cover. It can be a bear to keep in place as you set it on. Had a friend use up 3 as they kept falling out of place and cut on torque down on a 9-3. Finely just put a very little red RTV to hold it in place while getting the cover back on. With all that I also make sure to replace the crush washer and black O ring on the timing chain tensioner as it can leak oil. If you can't hot tank or you just want a cheep way to clean and have an air compressor use a Napa auto parts siphon gun and odorless mineral spirits.
 

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Discussion Starter #20
Thanks for the reply, very detailed! I’m learning a lot on this project. I put the plastic clutch cover back on and the flywheel mark lined up perfectly with the timing hole, not the raised line on the back plate like I expected.
Haven‘t spent much time on it for the last week. I did get the copper coated exhaust nuts, angle gauge, thread chaser kit and machinist straight edge. Been working on cleaning the gasket surfaces, not done but looks like head is straight.
Will send an update as it goes, hopefully make some progress this weekend.
Cheers
 
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