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I'm having to redo my head gasket because of a bad oil leak that developed between the head and the timing cover towards the back of the engine. I need to know exactly where to apply the Loctite 513 flange sealant. The WIS says how much to apply, but it really doesn't specify where exactly. In addition to where, I would also like to know if it's applied to the surface beneath the head gasket, between the head gasket and the head, or beneath and above the head gasket?

I also have a question about setting the timing. The timing marks on the intake cam line up perfectly in the position the camshaft naturally wants to lay in. This is not the case with the marks on the exhaust cam shaft. The last time I did this, I had someone hold a wrench on the bolt of the camshaft and line it up perfectly while I put the chain on. It took many tries of putting the chain on to get it perfect. I'm wondering if it's necessary for the timing marks to line up perfectly, or if putting the chain on when both shafts are in the relaxed positions is the better way to go. When I say relaxed position, I mean the position that the shaft goes to when turning the shaft without the chain on. The shaft "snaps" or clicks 4 times when you turn it. If I rotated it a tooth or two to make the marks line up, does that mean that a valve is partially opened or closed? I also ask this question because I had the head completely cleaned and redone and I sometimes (rarely), but sometimes hear a slight pinging.
 

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Discussion Starter #3
Help me out with the Loctite.... did you take the timing cover off?
I had the engine out last year, and replaced the timing and balance shaft chains and sprockets. I'm asking about the loctite, because the WIS lists this as a step to replacing the head gasket. It says if this step isn't done correctly, it would cause an oil leak.

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I just did a head gasket and the only sealant I used was a few tiny dabs at the “corners” of the semi circles on the valve cover gasket.

I set the timing by doing the exhaust cam first...I’m not sure why WIS specifies the intake first...

Have your helper hold the cam in place with a 19mm wrench on the end of the cam (the end opposite the sprocket). Install the sprockets so they are located with the tabs, but don’t take them to final torque. Install the tensioner then rotate the engine two full revolutions. All three marks should line up. If not...re-do. There is no close enough when it comes to cam/valve timing.
 

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Can you post a screen shot of the WIS instructions about the loctite? I had the WIS instructions printed out and do not recall anything about sealant.
 

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The only time the sealant is really used is to seal the pan, timing cover and rear back plate. Some people use a little RTV to hold the valve cover gasket in place or for the distributor plug but it shouldn't be required.

The reason to set the intake first is so the slack ends up on the exhaust side, that way when you install the tensioner it doesn't extend too far with all the slack.

If you have one cam lined up correctly then just count 15 pins on the chain to the other cam's mark.
 

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Had WIS open for some torque specs and sure enough, it says:

3. Carefully clean all sealing surfaces. Apply a 2 mm thick and 10-20 mm long bead of Loctite 518, part no. 93 21 795, to the inner part of the upper contact surface of the timing cover (against the cylinder head). Turn the engine in the stand, turning the crankshaft 45° to lower the pistons.
I've never heard of this before, but there it is.
 

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The only time the sealant is really used is to seal the pan, timing cover and rear back plate. Some people use a little RTV to hold the valve cover gasket in place or for the distributor plug but it shouldn't be required.

The reason to set the intake first is so the slack ends up on the exhaust side, that way when you install the tensioner it doesn't extend too far with all the slack.

If you have one cam lined up correctly then just count 15 pins on the chain to the other cam's mark.
I sure don't mean to be combative, but this makes no sense to me...

IF the timing marks are all aligned with their notches and THEN you introduce slack between the exhaust sprocket and the crankshaft...then, by necessity, when you start to turn the crankshaft, there will be a LACK of movement at the exhaust sprocket (both sprockets, really)...so, you would immediate be off time...

I aligned all three marks...eliminated any slack between the exhaust sprocket and the crankshaft...and mounted the sprocket. I then did the same between the two sprockets. So, ALL of my slack was on the tensioner side...where it should be. It literally took minutes and the three marks were perfectly aligned (and the chain was tensioned) after two rotations.

The WIS instructions for my car (1999...T5) don't say anything about flange sealant when installing the head...just when installing the timing cover. I wonder if the T7 head gasket design requires it whereas the T5 does not.
 

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If you pull the valve cover off and take note of the timing chain it isn't 100% taught all the way around (if it was then the gears and chain would wear a lot more than they should). The tensioner takes up some (the excess and more has things wear) slack but not 100% of it. If you reassemble an engine with a 100% of the slack on the intake side and then install the tensioner it can take up too much slack vs. if it was more evenly distributed on both sides. By starting with the slack on the exhaust side, the tensioner gradually takes up the right amount of slack as you rotate the engine by hand.

Personally I normally just try to split it somewhat evenly rather than pulling all the slack to one side, but the reason above is why the WIS states to start with the intake side first.

If you have enough slack that it would effect timing (either from the chain jumping or the timing marks being a tooth out) then you need to replace the timing gear/chain.

The T5 HG is a fiber one vs. the metal of the T7 so maybe that is why it doesn't spec the sealant, it tends to squish and seal a little better under the lower clamping torque furthest from the head bolts.
 

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Of course the chain isn't so tight as to introduce wear to the components, but the tension I applied to the chain in installing the exhaust sprocket was the same as what the crankshaft would apply in the other direction when the engine is running...

With the timing marks aligned, pull the chain (between the crank and exhaust) taut and lay it over the exhaust sprocket. In this case, taut is a straight chain without enough slack to 'hook' the next link of the chain. IOW, if you pulled it any more taut, you would move the crankshaft off of its timing mark. I hesitate to call that 'having slack'...it is as taut as possible while maintaining the timing alignment.

Again, there is no way you want slack between the exhaust sprocket and the crankshaft when their timing marks are aligned with the notches. As soon as the crankshaft starts to move, your timing would be off (because the cam sprockets wouldn't move until that slack is eliminated). Same with the intake sprocket, pull it taut from the exhaust sprocket and install. Now, you have a taut chain from the intake sprocket to the exhaust sprocket to the crankshaft sprocket...that is the definition of a properly timed engine. The tensioner side should be where ALL of the slack is.
 

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The WIS instructions for my car (1999...T5) don't say anything about flange sealant when installing the head...just when installing the timing cover. I wonder if the T7 head gasket design requires it whereas the T5 does not.
There is no sealant on the old B202 engines, either, so I'd 100% buy into it being a T7 thing. Maybe noteworthy, the place they say to apply it is precisely where my '01 convertible was leaking, so anecdotally I'd say there's value to it. :) I don't entirely understand why the block->gasket side would need sealant while the gasket->head side does not, but maybe something about the gasket's multilayer construction.

Glad to have learned this, because I'm thinking about doing a pre-emptive HG on a motor, and I would not have even thought to look up how. Done dozens and dozens of HGs on Saabs!
 

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Discussion Starter #12
I have a serious oil leak. The oil seems to becoming out between the head and the block beneath where the timing chain tensioner is located. I double checked to make sure it wasn't the tensioner itself. What would cause oil to leak there? Aside from possibly not using applying the Loctite 513 in the right place. At one point, I had bent the head gasket by trying to reinstall the timing cover with the head and head gasket in place. I can't remember if I replaced the gasket after that happened, but I have a brand new OEM gasket for this repair. I'm not chancing anything. I also just remembered that I have some OEM flange sealant #90297970. I used this for the oil pan and timing cover. I called and talked to an Orio tech who told me that Loctite 513 and Flange Sealant 90297970 are interchangeable. Even though I had ordered a new tube of Loctite 513, I'll probably use the OEM flange sealant. The leak got so bad that I was having to put in a quart of oil every 50-100 miles. I've also had problems with serpentine belts popping off. I figured this was happening because the belts and pulleys were getting oil on them from the leak.
 

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Discussion Starter #13
Of course the chain isn't so tight as to introduce wear to the components, but the tension I applied to the chain in installing the exhaust sprocket was the same as what the crankshaft would apply in the other direction when the engine is running...

With the timing marks aligned, pull the chain (between the crank and exhaust) taut and lay it over the exhaust sprocket. In this case, taut is a straight chain without enough slack to 'hook' the next link of the chain. IOW, if you pulled it any more taut, you would move the crankshaft off of its timing mark. I hesitate to call that 'having slack'...it is as taut as possible while maintaining the timing alignment.

Again, there is no way you want slack between the exhaust sprocket and the crankshaft when their timing marks are aligned with the notches. As soon as the crankshaft starts to move, your timing would be off (because the cam sprockets wouldn't move until that slack is eliminated). Same with the intake sprocket, pull it taut from the exhaust sprocket and install. Now, you have a taut chain from the intake sprocket to the exhaust sprocket to the crankshaft sprocket...that is the definition of a properly timed engine. The tensioner side should be where ALL of the slack is.
Thank you. This is good information to know.
 

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Thank you. This is good information to know.
If it's not already apart, a few paint marks are still a good idea. If it's too late for that, my method is fairly fool proof. Based on Internet research, I'm going to suggest that the WIS method is not as straightforward and often leads to mistakes.
 

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You keep saying "Loctite 513" but I really think you mean Loctite 518. 513 is a thread sealant. 518 is a flange sealant.


I have a serious oil leak. The oil seems to becoming out between the head and the block beneath where the timing chain tensioner is located. I double checked to make sure it wasn't the tensioner itself.

That's the leak I had on that '01, and mine was fixed with a head gasket retorque. Since yours is new, it's unlikely that's your solution UNLESS you re-used the head bolts, which you should not have.


At one point, I had bent the head gasket by trying to reinstall the timing cover with the head and head gasket in place. I can't remember if I replaced the gasket after that happened

You better have. A bent head gasket is trash.
 

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Of course the chain isn't so tight as to introduce wear to the components, but the tension I applied to the chain in installing the exhaust sprocket was the same as what the crankshaft would apply in the other direction when the engine is running...

With the timing marks aligned, pull the chain (between the crank and exhaust) taut and lay it over the exhaust sprocket. In this case, taut is a straight chain without enough slack to 'hook' the next link of the chain. IOW, if you pulled it any more taut, you would move the crankshaft off of its timing mark. I hesitate to call that 'having slack'...it is as taut as possible while maintaining the timing alignment.

Again, there is no way you want slack between the exhaust sprocket and the crankshaft when their timing marks are aligned with the notches. As soon as the crankshaft starts to move, your timing would be off (because the cam sprockets wouldn't move until that slack is eliminated). Same with the intake sprocket, pull it taut from the exhaust sprocket and install. Now, you have a taut chain from the intake sprocket to the exhaust sprocket to the crankshaft sprocket...that is the definition of a properly timed engine. The tensioner side should be where ALL of the slack is.
I understand what you are saying, I was just stating the reason for the WIS suggesting the intake cam first, its so the slack moves from the exhaust side to the intake side (where the tensioner) when you first crank over the engine. I didn't write the WIS, just stating the reason that it is the way it is. FWIW I don't follow the WIS procedure exactly either. TBH you only need to align one cam gear and then put 15 pins between it and the other cam gear mark and it'll be correct, no need to align the 2nd cam to its marks.
 

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I always align both... first the exhaust, then rock the intake forward a tiny amount, catch the tooth, and let it rock back, moving slack to the tensioner. Works every time, dozens and dozens of Saab head gaskets. I always used to struggle with the intake-first approach and always ended up off a tooth. No real idea why!
 

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I understand what you are saying, I was just stating the reason for the WIS suggesting the intake cam first, its so the slack moves from the exhaust side to the intake side (where the tensioner) when you first crank over the engine. I didn't write the WIS, just stating the reason that it is the way it is. FWIW I don't follow the WIS procedure exactly either. TBH you only need to align one cam gear and then put 15 pins between it and the other cam gear mark and it'll be correct, no need to align the 2nd cam to its marks.
Maybe I'm being obtuse, but I just can't understand how you are supposed to have the three marks aligned AND slack between the exhaust sprocket and the crankshaft. Those two things cannot exist simultaneously without the valve timing being off after the requisite two revolutions.

It's clear from reading various Internet stories that the WIS method often leads to errors. The confusion is compounded when the chain components are worn.

Your "15 pin method" makes perfect sense, too...as long as you work backwards from the crankshaft. That is, if the exhaust cam is the first one you install (with no slack between it and the crank)...then, 15 pins to the intake...is essentially what I did (except I just made it taut...I didn't count pins). If you go the other way (15 pins from the intake THEN set the exhaust sprocket), I can easily see one ending up with slack between the exhaust sprocket and the crankshaft...which will instantly throw the timing off.

It's unfortunate that something that is really VERY straightforward has been so consternating for some.
 

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It's not that you are meant to have slack between the crank and exhaust cam, its just that following the WIS instructions that you end up with a little that way. I think the WIS makes the assumption that everything is new/not worn enough that there is no excessive slack (or not enough to effect the timing).
Then as you crank the engine over by hand the little bit of slack moves to the intake side and allow the tensioner to take any slack up as you rotate the engine rather than upon installation of the tensioner prior to rotating the engine.

I fully agree with all you are saying, was just trying to answer the question of why the WIS says what it does, not to say anyway is better than the other. Personally as long as the marks are all close and you have 15 pins between the gear marks it should be fine, any problems will quickly show up after a few revolutions if it isn't right.
 

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I have a serious oil leak...
I'm not sure if you are saying the leak is between the head and the top of the timing cover, between the bottom of the timing cover and the sump, or somewhere between the timing cover and the block on the intake side of the block.

It's important to remove all the old sealant so you have perfectly clean, flat mating surfaces and then lay down a nice bead of the anaerobic sealant one surface. I just did this and used aircraft stripper followed by power washer which removed almost everything.

The 518 is first used on the timing cover to block mating surfaces (the backside of the timing cover). The crank side of the head and the sump both fit across the block and the timing cover. I've never been sure if WIS is telling you to spread some sealant across the "gap" where the block and the timing cover meet or along the section of the timing cover that seals against the head and the sump. To be safe I apply to both the gaps and down the center of the timing cover top/bottom like an "I".

If the top and bottom are well sealed against the head and sump, perhaps the timing cover mating surface was not properly cleaned, scratched or dinged up?

I've laid the sealant on a bit heavy and later found the sump pickup filled with jelly-like particles. To be safe, I'm changing the strainer mesh on the sump pickup to a #20. I am not capable of applying the perfect bead of 518 and who knows, maybe I'll pick up a couple of extra psi of oi pressure.
 
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