B6 A4 3.0 Serpentine Belt Tensioner

[Manchicle]

Hey guys. I'm new here and this is going to be a lengthy post, but I hope it gathers some good info about what looks like a common problem.

2003 A4 3.0, 63k miles. Owned it for two years, haven't done the timing belt yet, the plan has been to do it this spring (once it warms up). For about a month I've had an intermittent belt "grind" sort of sound. I've been popping the hood and looking/listening on each start, and the noise seemed to be accompanied by a nice, significant wobble of my harmonic balancer (crank pulley). Great. Online research and a little deductive reasoning brought me to the conclusion that the centering key on my crank sprocket had sheared off and my timing was in jeopardy. Needless to say, I've been working on a plan to sideline the car.

Last night, sitting at a light a few miles from home, the grind became a screech for a second, went away completely, and a huge plume of stinky smoke went up from my engine bay. I don't know if I've ever been so relieved to see a battery light and a tach at idle. Tugged on the steering wheel to confirm... yep, I just threw the serpentine belt. Muscled it home no problem, popped the hood, and fished this out:



I noted some extreme wear on the backside of the belt, almost as if it has been... burning rubber! I didn't even have to reach in to know that the tensioner had locked up (but I did anyway). Well, this is a lot more manageable. And on top of that, with the serpentine belt off, the engine ran smooth as ever, no crank wobble in sight. I was able to pick up a serp belt, tensioner, and the bulk of my tools today. Now that I have tomorrow's project in front of me, I figured I'd get my questions out of the way.

I like torque specs. Anybody got em for the tensioner assembly? Does the PS pulley have to be removed to reach the tensioner with a 19mm wrench? That could be a problem without a belt on it. And do you guys think that high resistance from a tensioner pulley could put enough drag on a harmonic balancer to cause a wobble, or should I still be concerned about the crank sprocket? I think I'll order one with an enhanced Blauparts kit this spring just to be safe.

My other concerns have to do with reaching the thing in the first place. Is Service Position necessary for this? It appears that some have been able to simply remove a fan, or even squeeze in and wiggle it out without touching anything. I don't mind taking some things apart. Service Position seems simple enough, but I couldn't find extra-long M8x1.25 studs at the hardware store to replace the special tools. Those of you with experience doing front end work, any tips or tricks would be much appreciated.

On a side note, I've always wanted to put together a little online forum pictorial to go along with a repair on my vehicle. With enough interest and temperature permitting, I'll try and snap some photos as it goes along. Thanks for your help.

[Jake@JHM]

Ouch!

We stock the B6 A4 3.0L Tensioner and Belt!


Service position is highly recommended when installing this. That way you can be sure everything is installed correctly. If you are able to, creating that DIY would probably help tons of people!

Jake

[zz2h33]

I put it in what i call "partial" service position which is basically remove everything from the front end except for the air conditioning lines and you can tilt the front end out of the way enough so you'll have plenty of room. you can use the 3.0 timing belt DIY for this work, but i strongly recommend doing the timing belt while you have it in "partial" service position since that is half the work of a TB job anyway. if the accessory tensioner went i have to suspect the timing belt tensioner is not too far behind and you do NOT want that to happen. this is the first time i have read that an accessory belt broke

[87supraman]

I just replaced mine. With this one, http://www.amazon.com/dp/B001FK4RPI/..._0SrQsb0VTQD5S
It was identical to the one I pulled out, minus the audi rings that had been ground off.

Sent from my SCH-I545

[Manchicle]

I put it in what i call "partial" service position which is basically remove everything from the front end except for the air conditioning lines and you can tilt the front end out of the way enough so you'll have plenty of room.

Service Position has always been the problem here. I put off doing the diag on the grind because I knew I was going to be doing the T-belt soon, which would require putting the car in service position. A few online write-ups made this look daunting, something I would only want to do once. But the more research I do, the more it looks like I can do something like what you're describing, pulling the front carrier back just enough to get a ratchet down there. I'm a dealership tech with plenty of experience squeezing and wedging to bypass the removal of something. If all we're talking about is a dozen or two bolts, I don't mind doing this now and then all over again come T-belt time in the spring.

Currently, my understanding of "partial service position" is this: Remove the lower and upper bumpers, fog lights, etc. Eight bolts on the front side of the carrier, two of which you replace with long studs, and two bolts above each headlight. And its loose. At this point, is there enough slack in all of the hoses and wiring to slide the carrier out those few inches I need? I've seen online guides that ultimately remove the condenser and lay it aside, but that always seems to be followed by swinging the front carrier completely off the car (what I understand to be full service position). Is it necessary to remove or unclip anything other than the main bolts if you want to pull it back just a few inches? And any suggestions on supporting the carrier without the extra-long studs?

[SJorge3442]

I literally takes an extra 25min to take the whole carrier off. Then you have access to the whole front of the engine. I will never do any sort of work on my car again, without removing the entire carrier. The tensionor bolts are a pita to line up correctly and I wouldnt want to risk stripping out the holes to save like 20 min.

[Manchicle]

Well that was easy. Also very cold, which is why I don't have very many pictures. Only took about two hours. Partial service position worked out perfectly. I found a pair of videos and a couple of serpentine/timing belt write-ups that gave me a pretty good idea of what to expect. I found it easier to reach the 3 nuts on either side of the bumper by completely removing the fender liners, though it certainly took some patience fitting them back into place. Be prepared to lose a little washer fluid



With the bumper removed, its just a few bolts to get the whole front clip loose. I laid a folded tarp on top of the wheels and slid them underneath to support the carrier. The whole thing will try to fall out on you as you loosen the last few bolts. There isn't a whole lot of slack if you're leaving all of the coolant and refrigerant lines connected and in place, and there's a lot of plastic to potentially break, so I made sure not to let it slip or dangle. I pulled it out just far enough to put the front bolt above each headlight back in through the rear bolt hole in the carrier, just to be safe. That gave me plenty of clearance to get a standard ratchet/socket down to the 3 tensioner bolts. Here it is out of the car, up close:



Beautiful! I found those front covers and some ball bearing shards on the belly pan. Locked solid. The new one went in without much hassle. You're right about the tensioner bolts, the lower two kept trying to cross thread. A little patience and I got em all started right and torqued (had to settle for "hand tight"). Slipped the new belt on, un-pinned the tensioner... done. At this point I started it up to check my work, ran smooth and quiet. There was still the slightest twitch in the balancer, but no noise at all. Good opportunity to take a peek a the T-belt:



Not too bad. Definitely some wear from the pulleys, the beginnings of some stretch marks. Teeth look good, and nothing looks out of the ordinary. With no noise, I feel good about waiting till spring. I worked my way backwards and re-installed the carrier and bumper without issue. No left over bolts! I wanted to run the engine to charge up the battery, so I ran to the gas station for a top off. Throttle was nice and responsive, and I could finally pass a pedestrian without secretly wishing they were deaf. Crisis averted, until next time...

[KiwiAudi]

Hi Guys. This Audizine forum is a word of information. I have just done the belt tensioner on my 2003 3.0ltr Ouattro. Firstly I tried do do this without extending the front carrier, as I had read somewhere on here that it is possible to do this. Well what a mission that was. So after a coffee decided to have a go at extending the front carrier. What a piece of cake that was and not worth the effort of trying to do the job without doing this. This video was great! www.youtube.com/watch?v=kFmhJeDpLJU However, after getting the old tensioner out, I realized that I could have got away with only replacing the pulley. I see these are advertised on Ebay for a reasonable price, a lot less than buying the whole tensioner. Just replacing the pulley can be done without extending the front carrier, so a huge time and money saver. I made up a tool to release the belt tension out of a 19mm ring and open end spanner, cut the ring end off and welded on a piece of pipe about 300mm long at about 45 degrees. Just thought I would add my two cent worth, as I have benefited so much from information on the forum. Have a great day guys!

[RetremendoGS]

2003 audi A6 3.0 V6timing issues need of help.
Timing belt broke off. Due to a bad water pump pulley the belt came off. I heard and seen cams spin so timing is off. I replaced the water pump. I put a new belt on and I have placed the engine in TDC. Bought the cam lock tool but if the timing is off, Do i loosen the cam bolts from cams under the black plastic (in picture ) Do i turn the cams clockwise so i can match and sit the cam locking tool?

Where do i go from here?

[SJorge3442]

2003 audi A6 3.0 V6timing issues need of help.
Timing belt broke off. Due to a bad water pump pulley the belt came off. I heard and seen cams spin so timing is off. I replaced the water pump. I put a new belt on and I have placed the engine in TDC. Bought the cam lock tool but if the timing is off, Do i loosen the cam bolts from cams under the black plastic (in picture ) Do i turn the cams clockwise so i can match and sit the cam locking tool?

Where do i go from here?

Right now just get the tools to line up with the cams. I used brute force to rotate the cams from the pullys with my hands to align the cams. One thing though, if you lost the timing belt while the engine was running, you likely bent valves and just reinstalling a new timing belt isnt going to solve your problems. Its worth a shot, but your compression numbers wont be there I bet. Either way, you can't diagnose further without reinstalling the belt and doing a comp test across the motor.

[shurur9]

Also replace the aux belt tensioner bolt as well.
It has a history of shearing flush at the block.

First warning is inside wear on the aux belt..the belt slipping off the steering pump pulley (cheap belts), or ribs being worn down from 6 to 5 ribs(quality belts)..

[beb1900]

I know this is an old thread, but I found it helpful when replacing my tensioner pulley and serpentine belt recently. I did have one thing to add: after having no luck getting the new belt on (with a crescent wrench on the tensioner release tab, I couldn't quite get it down far enough to get the belt over the top pulley), I decided to take a smaller c-clamp, with the top half of the clamp over the tensioner lever and the lower half of the clamp under the edge of the crank pulley. I then slowly tightened the clamp, which pulled down (loosened) the tensioner, allowing me to easily get the belt over the top. Wish I'd thought of this first.

[john_gonzo]

More tricks: h3-0-serpentine-belt-removal-method