Survey; When did your cam adjuster/tensioner(s) fail?

[lswing]

Sold her in April of this year :-(

This is what my invoice says:
Attachment 15561
Labor was 3527.17 and parts were 157.28.

Ah bummer, good car, but nice to upgrade sometimes, bit less hassle and crazy repair bills. Well looks like the cam adjusters were left alone after all. Hope they hang in for current owner, seems they last many folks at least 150k miles...

[Ms_RS6]

I definitely do not miss the crazy repair bills that's for sure. I do miss the beast, nothing out there like it.
I test drove the S6 and really liked it, but then I got into an S3, that little car surprised me and I took the corners like it was a go kart! I have one on order now and with a tune, I'll be set!

[Bigglezworth]

Haven't changed this part out yet on any of the trio here. 121K, 125K, 245K on each respectively. If any one of them is 'due' it's the 245K. Am goiing to be doing an EGT sensor and a couple of other odds and sods on in over the next week so I'll check things out on the two heads then.

Out with the old, and in with the new.....

Clatter be gone.

[MaxRS6]

...but then I got into an S3, that little car surprised me and I took the corners like it was a go kart! I have one on order now and with a tune, I'll be set!

Woot! Congrats! With luck, I'll get to see you again and the car sometime on one of my TX adventures. Good luck and have a ton of fun with the new ride.

[Bigglezworth]

More pics of the R&R effort. Both sides swapped out in 4 hours including cleaning, swapping of old/new and R&R of valve covers. Passenger side was definately in much better condition than the drivers side. No clue why one side would wear predominently more than the other, but it was significant to say the least. Passenger side took an additional hour of work to address access challenges on rear with SAI system still in place on this car. Glad I have removed the SAI on my other rides.

[lswing]

Biggs, nicely done. Can I ship my car up to you next time? Hey, can you post or pm me where you got the new pads? I'm going to refurb my cam chain tensioner set and sell them. Cheers!

[DHall1]

Ditto ^^ ×2

[lswing]

Bigglez ain't so bad after all...

http://www.vorwerkauto.com/camshaft-...58109088k.html

[Turbowned]

Definitely doing this next timing belt service.... fingers crossed that they make it that long...

Has anyone replaced the actual chain(s) on the car? If so, when?

[Bigglezworth]

Has anyone replaced the actual chain(s) on the car? If so, when?

Not necessary. That's the entire reason for the tensioner.

[RS8]

Although if the plastic rails are intact, how do I know that it really works properly ?


Is this the correct values on my CamshaftAngle?
Or is something wrong with my values?





And what should you look for to know that it is not working as it should? (Is it only if there is a big difference between left and right that there is something wrong, or is there something more you should look for?)


And is it around 0 at idle and around 22 °KW from 3-5k rpm that is correct for a working cam adjuster?

[Bigglezworth]

Based upon what I've taken apart and put back to tegether a few times, I'd like to say that the tensioners in themselves don't alter cam timing persee.... Their design has upper and lower pistons that equally push outwards against the chain to take up slack necessary to install the cams and to further ensure that as the chain stretches ever so much with operating heat & time (mileage) that it remains taught and doesn't rattle. If your tensioner doesn't pressure up, you've got excessive grooves worn in the shoe(s), or if you've worn things bad enough to shattered a plastic shoe, then the angles of the intake cam to the exhaust could 'vary'. I say this based upon the fact thatalthough there is no physical way for the chain to (jump) teeth, if the tensioners don't pressure up sufficiently you have effectively increased the length of chain between alignment points on the sprockets on the one side while decreasing if on the other. If you tension both sides of the chain to equally take up slack, both cams will always have the same center to center alignment point, and the chain running around the sprockets for both will always keep the degreed alignment in the same place. Rob from Peter to give to Paul, and that alignment fails.

Now, that said, worn shoes will only introduce slack in the chain until the tensioner pressures up with oil. If a shoe has shattered, or of your tensioner isn't pressurizing up, you will certainly experience cam timing woes. Depending on RPM between accelerating/decelereating, I believe alter the angle of the intake cam to exhaust cam relation for a few degrees as the tailing cam (intake) catches up to the rotational requirements of the exhaust cam being driven by the ribbed timing belt. General signs of wearing tensioner shoes is audible valve clatter upon start-up that goes away in a second or two when the tentioners fill with increased oil pressure.

I was going to go to the lengths of degreeing the cams while I was overhauling various odds and sods on the one beast here, but in the end, deduced I could really only degree the exhaust cams to the crank, and that level of degreeing was done merely by tension on the ribbed belt. The exhaust cams of course use a keyway c/w plate to lock with the bar, but the sprockets for each are a tapered pressure fit and can rotate on the end of the cams prior to final seating/torquing in order to ensure the belt is snug. You do have the ability to move an exhaust cam forward or reverse a full tooth on the ribbed belt. I have merely looked to get the sprockets to rotate backwards against the crank until I hit full tension on the ribbed belt, and then torqued down the sprocket bolts.

[lswing]

There's a reading at idle that confirms a blown shoe or other severe issue. Think it's supposed to be 16? Mine was -4 I believe. Someone please refresh me on this, I think Dave may have known the numbers. Of course I was getting tons of clatter, and misfire codes. But before opening up the engine the cam adjust was confirmed to be way off via Vagcom.

Edit; As my first post on this tread states, 16-18 is good, and I logged -7, very bad. This is at idle.

[Bigglezworth]

There's a reading at idle that confirms a blown shoe or other severe issue. Think it's supposed to be 16? Mine was -4 I believe. Someone please refresh me on this, I think Dave may have known the numbers. Of course I was getting tons of clatter, and misfire codes. But before opening up the engine the cam adjust was confirmed to be way off via Vagcom.

Edit; As my first post on this tread states, 16-18 is good, and I logged -7, very bad. This is at idle.

Yep, your's were toast. The reading is for how far out the pistons are pushing. As the wear inceases, the pistons push out to take up slack, and that registers as an inceasingly negative number. There would have been pieces of plastic laying around in the head I'm sure with that low of a negative eading as the tensioner would have been extended as far as possible.

[lswing]

Yep, your's were toast. The reading is for how far out the pistons are pushing. As the wear inceases, the pistons push out to take up slack, and that registers as an inceasingly negative number. There would have been pieces of plastic laying around in the head I'm sure with that low of a negative eading as the tensioner would have been extended as far as possible.

What tensioner?

Yep, was riding on metal and the remaining plastic strewn around the head...I guess that gives a -7 reading.

[fukinavit]

There's a reading at idle that confirms a blown shoe or other severe issue. Think it's supposed to be 16? Mine was -4 I believe. Someone please refresh me on this, I think Dave may have known the numbers. Of course I was getting tons of clatter, and misfire codes. But before opening up the engine the cam adjust was confirmed to be way off via Vagcom.

Edit; As my first post on this tread states, 16-18 is good, and I logged -7, very bad. This is at idle.

Do you happen to know the group this is under in vagcom?

id like to check this out so I have an idea of wear as mine is at 200k.

[RS8]

Group 90

I have 0 or -1 °KW at idle and I have it also if I rev my engine.
but if I run and gas hard it is changed to 22°KW after 2500 rpm I think I was, but not if I run calmly then it doesn't change whatever rpm I have.

But I have another ecu that I also tested now and that one also have 0 or -1 °KW at idle but if I rev my engine standing still it changed to 22°KW after 1200rpm and holds it up to over 4000rpm ( I didn't want to rev higher standing still)

[hahnmgh63]

The variable cam timing is based off of engine speed and engine load so revving the engine in neutral won't be the same as an engine pull on the street.