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View Full Version : 2001 A4 2.8 left side cam tensioner



bigtoyz
03-01-2016, 12:15 PM
I have a 2001 A4 with a 2.8. It has several codes, mostly a misfire in cyl 4, 5, 6. New to Audi, I am assuming this is a bad driver side cam tensioner. Most of the time it runs fairly smooth, occasionally it will run rough, there is no excessive rattling or metal noise. So I am just ready to tear in to it. I have tried reading everything I can prior to starting. Mostly what I have read has been about the pass side. Can this be done without removing the timing belt? Removing the front bumper? Can it be done by lifting just the intake cam? The left and rear are 2 different sensors, correct? Is there a good DIY step by step a person can read for this job?
Thank you for any advise.

walky_talky20
03-01-2016, 12:57 PM
I would check your cam phase offset in VCDS (ie: the "how whack is my timing?" meter) so you have actual numbers to relate to the mechanical (belt/chain) timing. BEFORE you tear it apart. Check them now. Then after your repair, you can check them again. All science-y like.

bhusted
03-01-2016, 02:13 PM
^ good advise. Looking at the cam phasing can give you an idea of where or possibly where not the misfires are coming from. I would not want to go replacing the chain tensioner if you are not certain that it is the source of your problem.

As for the job of actually replacing the tensioner. To do it "right" you'll have to pull the timing belt as the tensioner lives under the metal cover on the front of the driver's side head. You can replace the tensioner only removing the intake cam if you are willing to cut away a small amount of the metal timing belt cover on the front of the driver's side head. I recently did this on my V8 and the process is essentially the same as the V6. I can take a picture of the piece that I removed if you like.

a4kamila6
03-01-2016, 02:17 PM
He is correct. If your tensioner needs replacement, change both, and you should probably change the chains while you are at it. I have attempted to remove the driver side tensioner, and all i can tell you is, dont try doing it without putting front into service position. I thought i could just lift the intake cam, take that out, and get the tensioner out that way. Long story short, after an hour of trying everything, wasnt happening. Best way to do it is put motor to tdc at crank, remove front, throw on cam lock bar, make sure everything is good, then go about loosening all 4 cams and replacing the cam tensioners. If you did your timing recently or PO did timing recently and everything looks new, only replace timing belt tensioner and the belt itself if need be. That is assuming its all new. If its not, might as well do entire timing.


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bigtoyz
03-02-2016, 07:07 AM
I recently bought the car for my son, was told it just had a new belt installed, and realized it had the codes set. When you talk cam phaze you are telling me to set the crank at TDC and then check each of the of the 4 cams to make sure the timing marks are lined up with the marks on the head, correct? I didnt understand the "check your cam phase offset in VCDS" part. I had read enough that if all 3 misfires are related to one bank then that was a pretty sure fire bad tensioner, thats why I was ready to replace it. I have never used a cam lock bar. Any idea where a person can find one? If it is a tensioner, the right is a different part than the left, correct? Does the front end (bumper, ect) need to come off for this job? Is there a good source to look up for a step by step? What your saying is if the last tech got the timing belt off even 1 tooth that might me the problem instead of a tensioner?
Thanks for all the info guys.

a4kamila6
03-02-2016, 08:36 AM
Bumper comes off, front end must be removed or atleast tucked back, which is risky cause pulling/stretching various hoses. so once front is removed, turn crank to tdc, begin to remove timing covers and etc. You might as well do entire timing. get a cam lock bar online. Many sites carry them, google is your friend. Two tensioners with chains will cost you around 380-400, basic timing kit is another 300-400. If you are not familiar with the process just add another 500-700 at a reputable shop and have them do it. Its not too hard but first time i did it, took me about 5-6 hours. The pros can do it in 2. Fix all leaks and vacuum hoses and etc and go from there


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crazyquik22023
03-02-2016, 09:21 AM
I recently bought the car for my son, was told it just had a new belt installed, and realized it had the codes set. When you talk cam phaze you are telling me to set the crank at TDC and then check each of the of the 4 cams to make sure the timing marks are lined up with the marks on the head, correct? I didnt understand the "check your cam phase offset in VCDS" part. I had read enough that if all 3 misfires are related to one bank then that was a pretty sure fire bad tensioner, thats why I was ready to replace it. I have never used a cam lock bar. Any idea where a person can find one? If it is a tensioner, the right is a different part than the left, correct? Does the front end (bumper, ect) need to come off for this job? Is there a good source to look up for a step by step? What your saying is if the last tech got the timing belt off even 1 tooth that might me the problem instead of a tensioner?
Thanks for all the info guys.

What walky is saying by check the cam phase offset in VCDS he is saying to see how much timing the cam adjuster is adding or retarding via VCDS. VCDS is a software to connect to VW & Audi cars if you are not aware. Checking that the cam to crank timing is correct is a good thing to check as well. If you google audi 2.8 cam lock bar it will give you several online vendors that sell it. And as bhusted said it is possible to remove the drivers side tensioner by cutting away some metal from the timing cover. If you do not want to do that then the correct way is to remove the timing belt and cam sprocket and this does require "removing" the front end or at least putting it in service position. Also have you checked for oil in the spark plugs holes?

walky_talky20
03-02-2016, 09:42 PM
It would help if you shared all of the codes you are getting. The exact code numbers.

To check the mechanical timing (belt timing), it does require the special lock tools. However, the ECU is pretty smart, so you don't have to do all that work to see how far off the timing is (how accurate the belt/chain timing is).

The ECU has a sensor on the crankshaft (we sometimes call this the crankshaft sensor). It also has a sensor on each intake camshaft (some may call these the cam sensors). The ECU knows exactly what the pulses should look like between all 3 sensors when the engine is perfectly in time (and the timing belt and chains have the correct amount of tension). As such, it is able to measure pretty accurately how far off they are when things are out of time. A little bit off is ok. There is a specified range it should be in. But if it's too far out, you can get misfires. It takes about 1 minute to check the numbers and see if timing (the relationship between the camshafts and crankshaft) is out of spec - either due to incorrect timing, lack of tension, or a stuck VVT adjuster. At idle, crack open VCDS and read block 093 (blocks 090-093 or so have to do with the cam phase / VVT functions).

bigtoyz
03-03-2016, 07:45 AM
I have a mac mentor with the latin program and I will record all codes tonight. Once recorded I will erase them to see what resets. And I am looking for a lock up bar now. I will be back tonight with info. It is pretty smooth running now. If it were'nt for the check engine light, it would be hard to tell there is anything wrong. I really appreciate the help.

bigtoyz
03-04-2016, 06:41 AM
Here are the codes it had stored. 16688 cyl 4 misfire, 16689 cyl 5 misfire, 16690 cyl 6 misfire, 16826 evap, and 17755 bank 2 cam position incorrect. I erased the codes, took it out for a drive with regular driving conditions and so far it only showed a cyl 2 misfire (I am going to check plugs/replace that one this weekend). I will also line up all the timing belt marks first to make sure the belt was installed correctly first. Because it recently had a new belt installed by a repair shop I assumed everything pointed to the left bank cam tensioner. What would be your guesses if the timing marks are correct?
This is my first audi but man am I impressed. It only has 120K miles but is VERY quality built. Very smooth engine, smooth handling.
Thank you

walky_talky20
03-04-2016, 10:23 PM
Ok, we got some codes! Misfire codes don't tell us much, other than you have problems on the other bank as well (4,5,6). You have one very important code, though:
17755/P1347/004935 - Camshaft Position Sensor 2 (G163) / Engine Speed Sensor (G28): Incorrect Correlation

This is basically a "Your Engine is Out of Time" code. This is almost always caused by a timing belt that has been incorrectly installed. There are no timing marks on this engine, so (officially) the cam lock tools are required to get it right. It seems like the shop who installed your belt probably didn't use the special lock tools, or didn't know the correct procedure for installing the belt.

Again, I would suggest checking the 'cam phase angles' using VCDS - if it is available to you. It takes 1 minute and will tell you instantly whether the timing is correct or not (and which bank is incorrect, and how much). It is more accurate than the cam/crank locks will ever show you.