Cam seals DIY - can you ease my confusion?
09-13-2012, 05:01 AM
#1
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Cam seals DIY - can you ease my confusion?
Hi guys. Just trying to get my head around my next DIY maintenance job - valve cover seals and associated cam seals.
To be honest, my brains are a bit fried from all the reading, though I'm pretty sweet on what to do for the valve covers and the cam adjuster seals/gasket, its the cam seals that I'm a tad confused with. I've bought a kit from Blauparts which includes four cam seals and the two end plugs (see pic). Re the four cam seals, obviously its two per bank, and I take it they fit on the cams at the opposite end to the cam chains - is that right?
Because I'm a bit of a newb when it comes to this sort of stuff, I'd love to leave the cams in place (not feeling too confident about taking them out), and maybe just loosen the cam caps as I've heard the seals just "slip" onto the cams? I'm a bit miffed as to how that can be though, so with the valve covers off, can I (or maybe not?) get these four cam seals and two end plugs replaced without removing the cam shafts? If so, has anyone got any write ups or tips as I'm finding it tricky finding much on these cam seals and end plugs? And the plugs, do they just fit on by hand?
One other thing, when I had my timing belt done last year at an Audi dealer, they also replaced the two cam seals at the front of the block (one per bank), the ones behind the timing belt sprockets. Just wondering if those are two different seals to the four I'm talking about?
Cheers heaps. M
To be honest, my brains are a bit fried from all the reading, though I'm pretty sweet on what to do for the valve covers and the cam adjuster seals/gasket, its the cam seals that I'm a tad confused with. I've bought a kit from Blauparts which includes four cam seals and the two end plugs (see pic). Re the four cam seals, obviously its two per bank, and I take it they fit on the cams at the opposite end to the cam chains - is that right?
Because I'm a bit of a newb when it comes to this sort of stuff, I'd love to leave the cams in place (not feeling too confident about taking them out), and maybe just loosen the cam caps as I've heard the seals just "slip" onto the cams? I'm a bit miffed as to how that can be though, so with the valve covers off, can I (or maybe not?) get these four cam seals and two end plugs replaced without removing the cam shafts? If so, has anyone got any write ups or tips as I'm finding it tricky finding much on these cam seals and end plugs? And the plugs, do they just fit on by hand?
One other thing, when I had my timing belt done last year at an Audi dealer, they also replaced the two cam seals at the front of the block (one per bank), the ones behind the timing belt sprockets. Just wondering if those are two different seals to the four I'm talking about?
Cheers heaps. M
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09-13-2012, 05:46 AM
#3
You certainly can replace the cam seals and plugs without removing the camshafts or even loosening the bearing caps. It will be very obvious when you do the disassembly. You will be able to simply slide the old ones off and the new ones on.
The configuration is not symmetrical - if I remember correctly there are 3 seals at the front and 1 seal and 2 plugs at the back but they are all easy. This is because the chain adjusters and cam position sensors are on opposite ends. Either the adjusters or the position sensors don't have seals, can't remember which.
The ones you had replaced already are among the ones you have replacements for now. You might as well go ahead and use all the new ones you have anyway though.
The hard part of what you're doing imo is replacing the chain adjuster seals and gaskets on the passenger side - the adjuster is at the back and access is difficult I removed the cams on this side in order to get access but actually I wouldn't recommend that - just take the tension off the adjuster and maybe loosen the bearing caps if necessary. Obviously do the driver's side first to get a feel for how it's done.
You absolutely need the special tool if you want to replace the chain adjuster seals (it screws down into the adjuster to take the tension off the chain).
Finally...since you had your timing belt done recently, know that you'll be doing all that work again. Are you sure you know what's leaking? If it's just the valve cover gaskets, you can do those without touching the timing belt.
The configuration is not symmetrical - if I remember correctly there are 3 seals at the front and 1 seal and 2 plugs at the back but they are all easy. This is because the chain adjusters and cam position sensors are on opposite ends. Either the adjusters or the position sensors don't have seals, can't remember which.
The ones you had replaced already are among the ones you have replacements for now. You might as well go ahead and use all the new ones you have anyway though.
The hard part of what you're doing imo is replacing the chain adjuster seals and gaskets on the passenger side - the adjuster is at the back and access is difficult I removed the cams on this side in order to get access but actually I wouldn't recommend that - just take the tension off the adjuster and maybe loosen the bearing caps if necessary. Obviously do the driver's side first to get a feel for how it's done.
You absolutely need the special tool if you want to replace the chain adjuster seals (it screws down into the adjuster to take the tension off the chain).
Finally...since you had your timing belt done recently, know that you'll be doing all that work again. Are you sure you know what's leaking? If it's just the valve cover gaskets, you can do those without touching the timing belt.
09-13-2012, 07:45 AM
#4
I understand your confusion on this - unless you've torn things apart and seen how it all goes together, it is hard to get your head around the cam seals.
While you CAN replace the cam seals without removing the cams, it won't be easy, IMO. I typically loosen the end cam cap so that I have better access. If you are just going to replace just the rear cap (1) and seal (1) then you will just need to open the valve cover and undo the 4 torx bolts that hold down the end cap and you'll see them right there. Again you could do these without removing the one cap, by prying out the old cap and seal and pressing a new one in, but this will make it much easier IMO (especially if you've never seen how they go in). Plus you will be messing around trying to get a pry tool in between the back of the engine and the firewall, which can be a hassle. If you were just doing the plug, I'd say go for it, but the seal is a bit harder.
On the front, you can get the seals off, but you will have to remove the timing belt sprockets - which means removing a bunch of stuff and the front end of your vehicle most likely. This is why I usually recommend replacing the CAM seals when doing the timing belt job - you're pretty much there and they just slide off and on and you're done.
If you're using the write-up that shows how to replace the cam seals/valve cover seals by just removing the valve covers, loosening the tensioner (with the tool) and sliding the seals under the tensioner, etc. - you aren't far enough into the engine, IMO to get the front seals replaced.
If it were me, I may even ignore the valve cover leak until the next timing belt change - depending on how long it would take until I hit the next change and how badly it was leaking. If the leak is minimal, no worries. If it's flowing out and you're losing a lot of oil I'd be more conserned. If you have 25,000 more to go until your next change and you'll hit that in a year - then I'd wait until the timing belt change. In my opinion, it's so much easier when everything is apart than to work around what's there just to fix a common leak.
If you know the leak is on the back end of the engine, and you want to do the job now, just replace the back seals/plugs and not the front when you do the valve cover/cam seals.
While you CAN replace the cam seals without removing the cams, it won't be easy, IMO. I typically loosen the end cam cap so that I have better access. If you are just going to replace just the rear cap (1) and seal (1) then you will just need to open the valve cover and undo the 4 torx bolts that hold down the end cap and you'll see them right there. Again you could do these without removing the one cap, by prying out the old cap and seal and pressing a new one in, but this will make it much easier IMO (especially if you've never seen how they go in). Plus you will be messing around trying to get a pry tool in between the back of the engine and the firewall, which can be a hassle. If you were just doing the plug, I'd say go for it, but the seal is a bit harder.
On the front, you can get the seals off, but you will have to remove the timing belt sprockets - which means removing a bunch of stuff and the front end of your vehicle most likely. This is why I usually recommend replacing the CAM seals when doing the timing belt job - you're pretty much there and they just slide off and on and you're done.
If you're using the write-up that shows how to replace the cam seals/valve cover seals by just removing the valve covers, loosening the tensioner (with the tool) and sliding the seals under the tensioner, etc. - you aren't far enough into the engine, IMO to get the front seals replaced.
If it were me, I may even ignore the valve cover leak until the next timing belt change - depending on how long it would take until I hit the next change and how badly it was leaking. If the leak is minimal, no worries. If it's flowing out and you're losing a lot of oil I'd be more conserned. If you have 25,000 more to go until your next change and you'll hit that in a year - then I'd wait until the timing belt change. In my opinion, it's so much easier when everything is apart than to work around what's there just to fix a common leak.
If you know the leak is on the back end of the engine, and you want to do the job now, just replace the back seals/plugs and not the front when you do the valve cover/cam seals.
09-13-2012, 07:50 AM
#5
While you CAN replace the cam seals without removing the cams, it won't be easy, IMO
09-13-2012, 09:03 AM
#6
No, I mispoke there - you are correct. removing the cams does not make it easier. Removing the 1 end cap on the cams does though.
i.e. - leave the cams in place and all the caps in place, just take off the 1 cap over the seals you're replacing...it opens it up and they slide right off/on without fighting to squeeze them into a tight hole. Then replace the cap and tighten down and it's tight without risking damage to the cam seals by pressing them in. It works both ways, I just find removing the cam cap easier than trying to reach where I can't see.
Thanks for pointing that out...I didn't mean it that way.
i.e. - leave the cams in place and all the caps in place, just take off the 1 cap over the seals you're replacing...it opens it up and they slide right off/on without fighting to squeeze them into a tight hole. Then replace the cap and tighten down and it's tight without risking damage to the cam seals by pressing them in. It works both ways, I just find removing the cam cap easier than trying to reach where I can't see.
Thanks for pointing that out...I didn't mean it that way.
09-16-2012, 04:47 AM
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Cheers guys! The murky waters are clearing. I had a bit of a look over the engine today to get a feel for what's in store and that combined with your comments has helped a lot.
FYI I have two fair sized leaks at the front of the engine. On the front right corner (of the car), I'm sure it's the valve cover seal that's leaking and on the front left (again of the car) I'm pretty certain it's the cam adjuster seal/gasket that's leaking.
In order to make sure though, I took the timing belt covers off today and had a good look around to see if it could be the cam seals behind the timing belt sprockets that the dealer replaced that could possibly be leaking.
When those seals leak, does the oil leak into the inside of the timing belt covers, or does it run down between the rear of the cover and the block?
Everything looked dry behind the sprockets and inside of the covers.
If those cam seals are leaking, I'll go back to the dealer as it's under warranty. If you guys think they're not leaking, then I'll just do the valve cover gasket job as I'm not skilled enough to take the timing belt on and off to redo those front seals (that's why I went to the dealer for that).
Thanks too for the heads up that I can change the two other seals and the end plugs with the cams in place. I'm still a bit puzzled as to where these other two cam seals and the end plugs are located on the heads though? I couldn't see the plugs when looking at the engine today? And the two cam seals, I understand they're near the knock sensors (?), but is that at rear of the engine, on the inlet or exhaust cams?
Lastly, do I have to disconnect the two fuel lines where they join the fuel rail on the right bank in order to get that valve cover gasket replaced?
Cheers for your help. M
FYI I have two fair sized leaks at the front of the engine. On the front right corner (of the car), I'm sure it's the valve cover seal that's leaking and on the front left (again of the car) I'm pretty certain it's the cam adjuster seal/gasket that's leaking.
In order to make sure though, I took the timing belt covers off today and had a good look around to see if it could be the cam seals behind the timing belt sprockets that the dealer replaced that could possibly be leaking.
When those seals leak, does the oil leak into the inside of the timing belt covers, or does it run down between the rear of the cover and the block?
Everything looked dry behind the sprockets and inside of the covers.
If those cam seals are leaking, I'll go back to the dealer as it's under warranty. If you guys think they're not leaking, then I'll just do the valve cover gasket job as I'm not skilled enough to take the timing belt on and off to redo those front seals (that's why I went to the dealer for that).
Thanks too for the heads up that I can change the two other seals and the end plugs with the cams in place. I'm still a bit puzzled as to where these other two cam seals and the end plugs are located on the heads though? I couldn't see the plugs when looking at the engine today? And the two cam seals, I understand they're near the knock sensors (?), but is that at rear of the engine, on the inlet or exhaust cams?
Lastly, do I have to disconnect the two fuel lines where they join the fuel rail on the right bank in order to get that valve cover gasket replaced?
Cheers for your help. M
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09-16-2012, 04:59 AM
#8
If you change the cam seals without removing the caps, you risk scratching the cam and creating a leak at the new cam seal...a leak that can only be fixed by replacing the cam. jseklund's advice is good. Remove the valve covers and cam caps to change cam seals and plugs.
As for the locations of all this stuff, all seals are at the ends of the cam shafts. On bank one, there are there are two cam seals at the front of the engine, one behind the sprocket and one under the cam position sensor (the little cover thing partially hidden be the metal timing belt cover). At the rear is a plug and a cam position sensor. Since the two heads are the same casting, bank two (US driver's side) has only cam sensor at the front along with the cam adjuster unit (the source of one of your leaks, no doubt). At the rear is plug and the another cam position sensor that hides the fourth cam seal.
It it extremely unfortunate that this work was not done with the timing belt. Be sure you have the crank pin and cam locking bar to reset cam timing after you are done with the seals.
Find somewhere else to service your car.
As for the locations of all this stuff, all seals are at the ends of the cam shafts. On bank one, there are there are two cam seals at the front of the engine, one behind the sprocket and one under the cam position sensor (the little cover thing partially hidden be the metal timing belt cover). At the rear is a plug and a cam position sensor. Since the two heads are the same casting, bank two (US driver's side) has only cam sensor at the front along with the cam adjuster unit (the source of one of your leaks, no doubt). At the rear is plug and the another cam position sensor that hides the fourth cam seal.
It it extremely unfortunate that this work was not done with the timing belt. Be sure you have the crank pin and cam locking bar to reset cam timing after you are done with the seals.
Find somewhere else to service your car.
09-16-2012, 06:35 AM
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I'm still a bit puzzled as to where these other two cam seals and the end plugs are located on the heads though? I couldn't see the plugs when looking at the engine today? And the two cam seals, I understand they're near the knock sensors (?), but is that at rear of the engine, on the inlet or exhaust cams?
I now see where the knock sensors/cam position sensors (also called Hall senders?) are on the inlet cams. Obviously I have to remove the knock sensor/cam position sensor and the bearing cap (that's the double bearing cap, right?) and reseal the bearing cap upon reassembly?
I also see that the end plug on the right bank is at the rear of the exhaust cam. So on the left bank, is the end plug still on the rear of the exhaust cam? And the cam seal on the inlet cam on the left bank, is it under the cam chain adjuster or at the rear of the cam near the knock sensor/cam position sensor?
Cheers. M
09-16-2012, 10:41 AM
#10
Yes on pretty much all counts.
Knock sensors bolt to the block under the intake. The sensors you are looking at cam position sensors/cps/hall senders. No knock sensors here.
The heads aren't different. They are the same. Exactly the same. Well, the castings are anyway.
Both cam plugs are at the rear of the engine on the exhaust cams. Exhaust cams are turned by the belt, so no sensor is needed since the ECU just assumes timing was set right during assembly. The intake cams are driven by the chain, and the cam adjusters can vary the intake timing relative to the exhaust, so a sensor is needed for each intake cam to let the ECU know what is going on. So the cam adjuster and cps unit are always at opposite ends of the same shaft.
Make sense?
Knock sensors bolt to the block under the intake. The sensors you are looking at cam position sensors/cps/hall senders. No knock sensors here.
The heads aren't different. They are the same. Exactly the same. Well, the castings are anyway.
Both cam plugs are at the rear of the engine on the exhaust cams. Exhaust cams are turned by the belt, so no sensor is needed since the ECU just assumes timing was set right during assembly. The intake cams are driven by the chain, and the cam adjusters can vary the intake timing relative to the exhaust, so a sensor is needed for each intake cam to let the ECU know what is going on. So the cam adjuster and cps unit are always at opposite ends of the same shaft.
Make sense?