Prospeeder

Thats good info, but if the tensioner has failed like how I said which oil pressure is applied to it all all times, It will look perfectly fine and in time with the engine off. As soon as it runs, the tensioner gets too much oil pressure fed to it as if its trying to advance the cam for VVT and the cam timing is put off and runs poorly. If he gets in there and finds that it looks good and is in time, the tensioner is still probably what is at fault.

I have a passat 1.8T in my shop for the exact thing, timing belt is dead on, but runs poorly and has cam to crank correlation codes. And also all the V6 cars I have had this happen to, are all bank 2 if I recall, which is strange lol

Rusty105

parts are on order for the Timing belt job, including cam lock bar and crank lock plug.

IF , IF the B2 timing chain tensioner went bad, where can I get one for a reasonable cost?, and Do the chains need to be changed. Car has 197K on the clock . if just the tensioner pads are worn, where can I get new?? Can they be changed?

Could it be a low oil pressure issue? But don't have the warning light/bell....

As a recap:
The code for intake camshaft bank 2 to crank inconsistent and misfire codes for all 3 cylinders on bank 2 are what are coming up right now. (I don't have the code numbers in front of me right now) The motor runs rough at idle, but gets better above 1200rpm or so. I haven't driven it in about a week, don't want to.

thanks!!
Rusty

CRuby

All,
Any chance the misfires on B2 could be caused by a bad Ignition Control Module for that bank? The cam/crank inconsistent code is what makes me think not. But a bad ICM will cause misfires to be isolated to a single bank. ICM much easier & cheaper to fix than chain tensioners. Maybe a swap of ICM (B1-B2, B2-B1) is a simple test to rule it out...or in.

Offhand I don't think it necessary to change the chain...unless you conclude the cam chain jumped a tooth, or the tensioner pad broke off. Then it's probably a bit more important if the chain got damaged, and a smaller cost relative to the tensioner.

I got my pads online, search "Audi A6 C5 cam chain tensioner pads". Forgot the cost, but they are easy to remove & replace...after the tensioner is removed from head. Will need the chain tensioner tool for this. AND be aware the tensioner for B1 is not the same as for B2. They are not interchangable. I know first hand, because I chased missfires on the car I bought for ~ year, only to find out prior owner switched tensioner (L-R, R-L). Check your tensioner p/n & be sure to get the same one.

Prospeeder

I personally, have had good luck with the cheap aftermarket timing chain tensioners on ebay. I tend to try and find ones priced int he 100-150$ range rather than the super cheap ones. Car has 200k miles on it, no reason to buy a 300+ dollar one. I would not just do the pads, These wear out inside as well as the solenoid failing. I just found out today that not replacing the chain is a risk, they can stretch and in the case I delt with today, the chain still touched the top of the valve cover and made noise even with a new tensioner. Old tensioner blew one of the pads off.

Timing Chain Tensioner Kit Valve Gasket for VW Audi 2 7L 2 8L Left Camshaft New | eBay

Rusty105

So, Got busy and dug into the motor. Took over an hour to remove the upper radiator hose from the radiator , but it came off. Any tips to help this go back on, and not seize together.

So the good:
Timing belt looks great and the timing was almost spot on. The cam sprocket on bank 1 was maybe 1/2 tooth out. With the crank lock pin in place, the cam lock bar basically fit right into Bank 2 sprocket, after rotating bank 1 sprocket about 1/2 tooth.

The bad:
For the life of me I could not remove the engine coolant plug at the back of the motor. Plug was way tight, I am going to leave it and just flush the motor a few times with distilled water.

Cam chain tensioner on bank 2 is missing the upper wear pad. I found part of it, but I am guessing the rest in in there somewhere. I guess I might a s well replace the pads on both sides. The metal shoe does not look bad at all, just a little brighter.

So any good how-tos for chain tensioners???


Also why do spark plug boots 2 and 5 have an Orange clip on them??

Rusty

CRuby

Having found a missing tensioner pad, I'd suggest you change all 4 pads (2 on each tensioner) before spending the $$ on new tensioners. New chain too because old chain was riding on metal pads. Did you get the tensioner tool yet...you'll need it. Don't over torque it or it could crack. AND keep track of tensioners bank 1 stays on bank 1. They are not interchangable btwn B1 & B2.

SloopJohnB@mac.com

There's a measurement to indicate chain stretch but I don't know what it is.
I think there's a standard stretch for most chains, like ½ a link for 10 or 20 links; google it.
You could lay a new chain against 10 links of the old chain and I'll bet the old chain is less than 4mm longer over that length.

Rusty105

I replaced the pads on Bank 2. The bottom pad was groved, as well as the bottom of the pocket where the chain runs. The top pad was gone! I found maybe 30% of the pad, in pieces. No idea where the rest went. It does look like some of the pad was chewed up by the sprockets, as evident by the marks on the pad fragments. I didn't have too much trouble removing and installing the tensioner. And the chain looked ok, I'll look it over again.

Now for Bank 1, arrggghhhh. How do you remove the tensioner on that side? I did break the tool on that side, so I am on hold until the weekend. A new tool should come in on Friday. Is there a way to break the chain, ok I know there is a way, but is that an acceptable way to remove the tensioner?

I did notice one thing odd though. The square notches on the cams for Bank 2 line up with the space between rollers on the chain, where on Bank 1 they line up with the rollers ??

So my sticking point is getting B1 tensioner out And coolant drain plug on the bottom of the block. That sucker is tight!! Afraid I may break it, or the Allen socket tool..... Any tricks for that ???? How bad is it if I don't drain the block?

SloopJohnB@mac.com

It's likely the tensioners are at different openings which would allow the notches to change relative to the rollers. Unless the chain were badly stretched. A 3% wear (which is generally the worst case to replace a chain) wouldn't be enough to move the notches that far IMHO.

Bentley doesn't say squat about this, incidentally. The timing function is the notches in the camshaft line up with the arrows on the camshaft caps. THEN the camshaft chain has 16 rollers between. The pic below shows 14 so it depends on how you count. There are also a lot of pics on this forum on how to count cam chain rollers! I prefer 7 links (14 rollers) between the ones on the ends.

One other note: IF you choose to replace tensioners by removing camshafts, make sure you leave the engine alone, don't rotate the crankshaft, for 30 minutes after you install the camshafts/tighten the bearing caps. If you remove the camshafts the hydraulic lifters will expand and they need to collapse before you turn the engine over or you will likely/surely bend valve(s).
You may be able to replace tensioner by just removing the intake camshaft (you have to remove the double bearing cap but don't remove the exhaust cam single bearing caps), lifting and twisting it so the sprocket comes out of the camshaft timing chain, then taking the tensioner out, assembly is the reverse, just make sure the number of links between the two sprockets is correct. 16 rollers counts the rollers on the ends!.

Try http://www.diamondchain.com/chain-el...structions.pdf for a model on how to measure and when to replace roller chain.
PS: If you buy TWO tensioners, you'll never break one! LOL. Murphy rides the battlefield.

It's pretty much irrelevant if you don't drain the block. Just don't mix coolant types!! In 16 years of Audi ownership I've NEVER drained a 4.2 block other than dropping the lower radiator hose or when I've had to replace (twice) a coolant transfer tube in the 4.2 oil cooler assembly.

Rusty105

Yep, 16 counting the first and last.

If I can't get the intake cam out first, how bad is it to pull all three, the two cams and the tensioner, then put all three back in together?? Other then time....

As for coolant, It had orange G12(? assuming G12 ?) And the timing kit I got from Blauparts has a purple coolant. I could always do what I did years ago, and once the coolant is hot open the drain on the radiator and keep filling the reserve with distilled (can't find de-ionized) until it runs clear, then add enough concentrate to make a 50/50 in the system. So how big is the cooling system on a 2.8?


*******
OK, did a little reading, G12 is not orange Looks like I will buying a bunch of distilled water, and flushing