2.8 cam chain and tensioner replacement
11-17-2014, 11:39 AM
#83
AudiWorld Member
Also, IMO the Bentley discussion & pics of cam chain roller count aren't fully informative. They show pic of cam notches relative to cam sprocket teeth, but fail to mention that they are not the same between bank 1 & bank 2, & they don't tell you which bank their picture applies to. Also Bentley seems to indicate some difference if using an old or new chain, but I fail to see why they would be any different. Roller counts shouldn't be any different with a new or old chain, & chain stretch, if any, would be miniscule in affecting notch alignment.
Last edited by CRuby; 11-17-2014 at 02:26 PM.
11-17-2014, 01:45 PM
#84
AudiWorld Super User
Technically if the notch on exhaust cam lines up with arrow on end cam cap you have TDC. To make sure tough you would have to check the crank shaft line and arrow to line up(pic in previous post for reference). And put the crank lock pin in(that would the the safest surest way, with the crank lock pin, and you can find them on ebay cheap.)
If I were you, I'd buy a Bentley cd repair manual specific to your vehicle. You can go on the specs I provided if you want, but this is a 4.2 engine code ART.
Mark the chain as is and the sprokets for reference. If engine is at TDC remove intake cam caps. There is a sequence required provided in videos posted and pics. I'll try post some pics from instructions. I would at least read Blauparts instructions if you can't afford Bentley cd(though you would save lots of money by doing the labour yourself).
If I were you, I'd buy a Bentley cd repair manual specific to your vehicle. You can go on the specs I provided if you want, but this is a 4.2 engine code ART.
Mark the chain as is and the sprokets for reference. If engine is at TDC remove intake cam caps. There is a sequence required provided in videos posted and pics. I'll try post some pics from instructions. I would at least read Blauparts instructions if you can't afford Bentley cd(though you would save lots of money by doing the labour yourself).
Only if nothing else has been effed up or worn. There are ALSO TWO TDCs, each is 360 out from each other. IIRC you want the one with #5 piston at TDC or when the exhaust cam lines up closest to that mark AND the pin gozinta the crankshaft.
11-17-2014, 06:41 PM
#85
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Yeah, forgot to mention, all pics are for left bank 4.2 engine code ART which I thought he was working on(different engine, but left bank). Right side bank specs as far as chain rollers count goes are different...
11-18-2014, 08:17 AM
#86
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I do have this section of Bentley ... I am also aware of the cam removal sequence.
so you would remove the intake cam and not the exhaust? is there any reason for that? would it matter which one to remove in order to replace the tensioner?
so you would remove the intake cam and not the exhaust? is there any reason for that? would it matter which one to remove in order to replace the tensioner?
11-18-2014, 09:14 AM
#87
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The timing belt is on the exhaust cam. If you are planing to do the timing belt job, go for it...I heard and saw pictures of timing belt zip tied to sprocket on exhaust cam so that it doesn't move when you lift the exhaust cam, but I wouldn't suggest that method because it would put too much pressure on the bearing caps, which are screwed into the aluminum head, very easily stripped; look at the torque numbers 3+ ft per pound and 1/2 turn: that is very little torque). If you didn't remove the timing belt cover you prolly don't know what I'm talking about 
you can peak through a little hole in the cover by the exhaust cam and see the timing belt...
Otherwise intake cam needs to be removed for tensioner to come out...
It would make the job easier for reinstalation (to put the cams back together) if you decide to do a timing belt job as well and remove both camshafts...
I spent one hour the first time trying to put the intake cam back in with the tensioner. I didn't remove the timing belt. It is tight even with the tensioner compressed. And you can't be one tooth off the notch/arrow plus the 15 rollers on chain. You'll understand more when you do it
you can peak through a little hole in the cover by the exhaust cam and see the timing belt...Otherwise intake cam needs to be removed for tensioner to come out...
It would make the job easier for reinstalation (to put the cams back together) if you decide to do a timing belt job as well and remove both camshafts...
I spent one hour the first time trying to put the intake cam back in with the tensioner. I didn't remove the timing belt. It is tight even with the tensioner compressed. And you can't be one tooth off the notch/arrow plus the 15 rollers on chain. You'll understand more when you do it
Last edited by indoor; 11-18-2014 at 09:30 AM.
11-18-2014, 11:54 AM
#89
AudiWorld Super User
Many pics on the forum about removing the intake cam and leaving the exhaust in place. Reason is so you don't have to mess with the timing belt, etc. And yes, it matters, because you have to remove the timing belt and sprocket to remove the exhaust cam.
11-19-2014, 12:15 PM
#90
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Went back to page six, and now I understand why my pics are useless here. Moe was talking about bank 1. That is passenger side. My Bentley pics are for bank 2. Well, he says he has the Bentley for this section(whatever that means) so all is well.
Good job Moe making it to the appropriate forum too!
Good job Moe making it to the appropriate forum too!