3.0L valve cover bolt torque
#1
Audiworld Senior Member
Thread Starter
3.0L valve cover - can they warp?
Is it really 10 Nm for valve cover bolts on the 3.0? Bolts came off with a snap - definitely not 10Nm (that was done by an Audi indy) and have a leaky valve cover gasket. Started leaking after timing belt service at the back lower corner of the valve cover. Took it back and he put a new gasket on. Still leaking. Today, I pulled the vc off and had a good look for cracks. Nothing. Mating surfaces were spotless. Gasket seal in the right places. Put a third gasket on and tightened in sequence. Leaking in the front bottom area now. Can these plastic covers warp? Car has never overheated, but 204K took its toll on the crankcase vent pipes - had to replace all of them.
I looked at Blauparts videos but they are not for a 3.0L and they put quite a bit of sealant on whereas other threads I've read indicate they don't use any or very sparingly.
Is it still an art like it used to be on my old V8s? Dang.
I looked at Blauparts videos but they are not for a 3.0L and they put quite a bit of sealant on whereas other threads I've read indicate they don't use any or very sparingly.
Is it still an art like it used to be on my old V8s? Dang.
Last edited by ajg617; 06-30-2014 at 06:37 PM.
#2
I have only done this on a 2.7T but I can tell you that you don't need to use a lot of torque. I just make them firm and don't use a torque wrench - but you definitely do NOT want to overdo it. Those studs snap real easy, especially if you are using a slightly longer ratchet, and then you are in a world of hurt.
I use sealant around the valleys and corners. Are you sure it is the gasket that is leaking?
Not 100% sure on the 3.0 but the cam adjuster seals and cam shaft seals are also known to leak on the 2.7T, I would assume it's the same for the 3.0?
I use sealant around the valleys and corners. Are you sure it is the gasket that is leaking?
Not 100% sure on the 3.0 but the cam adjuster seals and cam shaft seals are also known to leak on the 2.7T, I would assume it's the same for the 3.0?
#3
Audiworld Senior Member
Thread Starter
I have only done this on a 2.7T but I can tell you that you don't need to use a lot of torque. I just make them firm and don't use a torque wrench - but you definitely do NOT want to overdo it. Those studs snap real easy, especially if you are using a slightly longer ratchet, and then you are in a world of hurt.
I use sealant around the valleys and corners. Are you sure it is the gasket that is leaking?
Not 100% sure on the 3.0 but the cam adjuster seals and cam shaft seals are also known to leak on the 2.7T, I would assume it's the same for the 3.0?
I use sealant around the valleys and corners. Are you sure it is the gasket that is leaking?
Not 100% sure on the 3.0 but the cam adjuster seals and cam shaft seals are also known to leak on the 2.7T, I would assume it's the same for the 3.0?
4th gasket on and letting the sealant cure over night. Test drive tomorrow.
#4
AudiWorld Super User
Oil is definitely coming from the valve cover. Cleaned the surfaces below ran, it for about an hour and it was soaked below the bottom of the cover near the front. My torque wrench only goes to 10 ft lbs or about 13.5 NM but I could barely hear the click, so I went and got a smaller one that gave me a good click and goes down to 3 NM.
4th gasket on and letting the sealant cure over night. Test drive tomorrow.
4th gasket on and letting the sealant cure over night. Test drive tomorrow.
#5
Audiworld Senior Member
Thread Starter
Put a straight edge across the bottom outside of the bolts and it was fine with the naked eye except for a slight gap on the outside rear lower corner (not leaking there now though that is where the original leak was). Bought a used cover just in case and put a straight edge on that and it had the same gap - could slide a piece of paper in on both on the outside but not from the inside.
If this doesn't work, I'll try a new cover though they are scarce. Audi says they have two - one in Santa Monica and the other in Ft. Worth - not exactly driving distance.
If this doesn't work, I'll try a new cover though they are scarce. Audi says they have two - one in Santa Monica and the other in Ft. Worth - not exactly driving distance.
#6
AudiWorld Super User
Put a straight edge across the bottom outside of the bolts and it was fine with the naked eye except for a slight gap on the outside rear lower corner (not leaking there now though that is where the original leak was). Bought a used cover just in case and put a straight edge on that and it had the same gap - could slide a piece of paper in on both on the outside but not from the inside.
If this doesn't work, I'll try a new cover though they are scarce. Audi says they have two - one in Santa Monica and the other in Ft. Worth - not exactly driving distance.
If this doesn't work, I'll try a new cover though they are scarce. Audi says they have two - one in Santa Monica and the other in Ft. Worth - not exactly driving distance.
#7
Audiworld Senior Member
Thread Starter
Think they'd laugh at me when I bring them in a plastic cover and ask them to mill it? Dunno, the gasket is inset into a gap between the cover edge and baffle edge. That spot isn't leaking now though. The leak is under cylinder 1 and the cover is dead straight there.
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#8
AudiWorld Super User
oh my appologies . i thought that cover was alluminum
#9
AudiWorld Super User
This is a classic case where additive machining would be a neat solution to the problem…holograph or 3D scan the plastic part, convert it to a CAM language and put it in the replicator and make it aluminum (or titanium or in the future, carbon fiber/epoxy), reinforce it in certain places as necessary.
I'm sure Audi made it out of plastic for a reason, probably cost and to a lesser extent weight, but an aluminum service piece might be a real plus.
I'm sure Audi made it out of plastic for a reason, probably cost and to a lesser extent weight, but an aluminum service piece might be a real plus.
#10
AudiWorld Super User
Put a straight edge across the bottom outside of the bolts and it was fine with the naked eye except for a slight gap on the outside rear lower corner (not leaking there now though that is where the original leak was). Bought a used cover just in case and put a straight edge on that and it had the same gap - could slide a piece of paper in on both on the outside but not from the inside.
If this doesn't work, I'll try a new cover though they are scarce. Audi says they have two - one in Santa Monica and the other in Ft. Worth - not exactly driving distance.
If this doesn't work, I'll try a new cover though they are scarce. Audi says they have two - one in Santa Monica and the other in Ft. Worth - not exactly driving distance.
OK..it sounds like your fasteners are loosing clamping force, either by the gasket failing (unlikely with new gasket in such a short time) or inadequate clamping force to begin with.
One thing I've found with all valve covers, even the old SBC (and especially BBC) tin valve covers is to use blue loctite when installed and if you're a belt and suspenders type even paint a stripe across the nut/bolt or bolt head/cover so you can tell if the nut or bolt turns. With the loctite, it's not likely anyway.
As for the torque you choose to use to fasten the cam cover, I'd stick to the factory values unless there is a specific leak in one spot that the fastener can eliminate by increasing the clamping force in that one spot….excessive torque can unevenly clamp the gasket and result in leaks.
Lastly, are there any aftermarket gaskets available, like from FelPro or a good supplier that may be improved over the OEM gasket? ECS for example has two sources, one OEM and the other Elring.
Amazing that an aluminum 2.7T cover costs $168 while the plastic 3.0 is $224. Yet another reason to damn the 3.0.
Last edited by SloopJohnB@mac.com; 07-04-2014 at 08:20 AM.