View Full Version : CEL and airbag light help needed

10-02-2010, 01:15 PM
Two months ago my wifes A4 threw a CEL light which I posted about here (http://www.audizine.com/forum/showthread.php/378100-Help-with-CEL-and-EPC). I changed out the crank speed sensor and all was good until today. When I first turned the car over there was buzzing sound for a second or two which seems to be normal for her car. Car seemed to be driving fine, then about an hour into the ride the CEL came on. When we pulled off the road I noticed immediately that at idle the car sounds like a freaking loud diesel. But if I gave it a little gas and got the rpms above 1500 it went away. When we got to a place to stop I opened the ood and was blown away by how loud it was and to me it sounded like it was coming from the top, not like an exhaust rattle. Sat down for a bit to figure out what I could do....had my pregnant wife with me and when we decided to try to drive it home it seemed fine. When I first started it the engine was fairly quiet. Eventually though the sound came back. Other than the lights and sound the car seems to be OK...when you drive on the highway the engine is quiet, seems to have power and doesn't seem to be pulling timing. When I got home I pulled the following codes.

16524 Oxygen (Lambda) Sensor B1 S2: No Activity
16395 Bank 1: Camshaft A (Intake): Retard Setpoint not Reached (Over-Advanced)

01217 Side Airbag Igniter; Drivers Side (N199)
32-10- Resistance too high- intermittent.

First on the airbag this did come on right away after I adjusted the seat. Saw several threads indicating that I should zip tie the crap out of it. If there are other suggestions please let me know.

As for the noise and the CEL what could this be? When I did a search of this 16395 it pulled up my recent post but then it was a 25-10 now it is a 35-00 but I have no idea what this means. I did find a thread saying the cam tensioner needs to be replaced. Any other thoughts on what this could be and how much it would cost to fix? As I mentioned above the wife is prego and money is getting tighter, as much as she loves this car I don't want it to be a money pit or worse yet leave her and the baby stranded somewhere. Oh in case it matters the car has had an aftermarket cat for ~80k miles, front O2 sensor is mounted normal, back sensor is in a spark plug defouler. Not even sure which O2 sensor is being flagged currently.

Any help would be greatly appreciated.

10-02-2010, 03:13 PM
The noise is from the cam chain tensioner (aka camshaft adjuster, CCT, etc). It is the tensioner for the chain that runs from cam to cam, at the back of the head. You symptoms are very common for a bad tensioner, although it is advisable to have the oil pressure checked as that can also cause problems with it (the tensioner uses oil pressure to function).

The tensioner for you car, a 2001, is a little more expensive than the earlier years, but prices have come down somewhat in recent months. A new aftermarket-sourced tensioner should be no more than $300. Dealership price would be $750 (just the part, not installed!). If you can do your own timing belt, you can probably handle replacing it yourself. Otherwise a shop would probably charge 2-4 hours to do it.

Your car will need the "K" version tensioner:
http://www.mjmautohaus.com/catalog/product_info.php?cPath=6169_6170_6186_6188_6726_89 83&info=OEM_VAG_058109088K_Cam_Timing_Chain_Tensioner _OEM&products_id=2180

For the airbag code, yes, it is the connector under the driver's seat. With the key off, unplug and replug it. Then ziptie it nice and tight so the connector stays tight together.

10-02-2010, 03:34 PM
I checked oil level and it was OK but have no way to check the oil pressure, at least not that I know of. I'll do a search to see if I can find out some info on pulling this off. I did find a walkthrough on another site for the replacement but I think it is going to be more than I want to do. I did look at ECS for the tensioner and was confused as to how the parts for an AWM could run from 200 to 700! Seems like a huge spread. If the oil pressure is the problem what is the fix? Just have a feeling that the oil may be the problem since keeping the rpms up got rid of the noise.

10-02-2010, 04:15 PM
I think I have the exact same problem with the sound. No cels or any lights but the sound is there. Is it this by any chance?


10-02-2010, 04:22 PM
That sounds pretty much the same....what I find really odd is that it doesn't happen all the time. At the beginning of the drive it did it only for a second or two at start up then like I said about an hour in it got bad. Then stopped again for a while and came back. But again this only happens at idle, when I get the RPMs up it goes away...or at the very least is pretty damn quiet. Could it be an oil pump going bad or sludge? We have been good about doing the oil changes but the car does have over 170k so maybe we just pushed it out further than most?

10-02-2010, 04:32 PM
hmm.. mine has 79k. Its pretty much loud all the time. Thats even how I bought it. I left it like that, doesn't seem to bother me that much.
Under higher RPM's, the noise is almost completely gone.

10-02-2010, 04:38 PM
Definitely not normal....how many miles have you put on it making this noise?

I had been hearing this same noise on cold startup for a while now that I have been thinking about it. Originally I thought is was something with the secondary air injection since it was only a transitory thing on cold start. Ugh...just don't know what to do with this thing.

10-02-2010, 04:45 PM
About 6k probably. Just never thought much of it.

10-02-2010, 08:21 PM
The clanking noise can sometimes be accompanied by the chain actually making contact with the underside of the valve cover, or even with the cylinder head. I would not advise to drive the vehicle more than absolutely necessary before you get it fixed. Here is a photo from when my tensioner failed.


Note the nice gash in the head from the chain making contact (directly above the "^13x" casting). If the chain is rubbing like that, you're getting metal chips in your oil...not good. I will say the *usual* failure doesn't involve chain contact, just rattle, but it can happen.

Yes, the price of the tensioners varies greatly. Genuine Audi parts are $650+. Aftermarket "OEM" (supposedly) parts are about $300, and the chinese ones are $200.

Generally speaking, if it is making that much racket at hot idle, the tensioner is junk. Checking the oil pressure is easy and should really be done before replacing such an expensive part, though. You need a mechanical oil pressure gauge with an M10x1.0 fitting. Your local independent foreign auto mechanic should be able to check the pressure for you. Shouldn't take him more than 30 minutes. Make sure to check it hot (ie: when it is clacking, preferable oil temp near 200F on the guage). Should be at minimum 14 psi at idle, above 20psi is normal. And at 2k rpms it should make around 50-60psi. When revved out it ought to be able to make about 90 psi or more.

10-03-2010, 04:04 AM
I might have a gauge laying around...where would be a good pick up point on oil pressure? Do I need to do it near the tensioner?

Was just thinking about this some more... for those that have had this problem with only the tensioner, did you have this sound the worst at idle and would it go away when driving? At first I was sure it was an oil issue because it only happens at low rpm, figuring that the oil pump makes more pressure at higher rpms and the noise goes away. But as I was thinking about it, higher rpms will inherently put more tension into the chain due to the cetrifugal forces. So the faster the engine spins the more slack that is taken out and the noise disappears???? I agree the best path forward is to test the oil pressure since that would be a much more costly fix than the tensioner and the tensioner is not stupid cheap or easy to replace. Just need some assistance on where I can pick up this pressure. I would rather not be driving this thing around much.

Thanks again guys for the help.

10-03-2010, 10:03 AM
When mine went bad it only made the noise at hot idle. Raising the revs to 1500 or more would make the noise stop. It got to the point that at traffic lights I would drop in neutral and hold the revs higher just to stop the noise. After replacing it all the noise was gone.

It seems that when they fail they become more sensitive to oil pressure. In other words, they require like 40 psi of pressure to operate when they ought to only need about 20 psi. When the oil is cold, you get a lot more oil pressure, about 80 psi at idle. When it is fully warmed up you get about 20-25 psi at idle.

Checking the pressure is advisable due to the parts cost, but you do have the most common failure mode of the tensioner: rattle at hot idle. The problem here is a possible partially clogged pickup screen that is lowering the oil pressure. If you are only getting 10psi at idle, you've got problems other than the tensioner (ie: clogged pickup).

There is 2 places to connect the oil pressure gauge. One is the plug on top of the oil filter housing. It is a 5mm allen plug w/copper washer and m10x1.0 straight threads. The other is by removing the oil pressure switch (on the rear of the oil filter housing) and connecting the gauge there (same threads). Both give the same reading. I thought the top port was reasonably easy to access with a 3/8 drive "wobble" extension through the intake runners and a 3/8 drive 5mm allen socket. Most people seem to prefer to use the oil pressure switch port, though. Here is a photo of the housing. The "plug" is in red:


10-03-2010, 10:34 AM
Thanks, I will try to pick up a decent gauge and some fittings to test teh oil pressure. Since oil temps have a lot to do with the pressure, I will need to get the car warmed up....would it be better to drive it since it will warm up faster and oil pressure will be higher or do I just let it sit but keep the revs up?

OK so <14 psi I should consider doing something like Seafoam then drop the pan and clear out the mess then retest? If it is still under 14 do I consider an oil pump?
14-20 psi what do I do? If the tensioner uses the oil pressure to function could a failure of this part cause pressure loss as well?
If it tests over 20 I'll have the tensioner changed.

10-03-2010, 11:28 AM
1 bar (14.5 psi) is the minimum pressure per the Bentley manual, at 180F oil temp. But people have noticed that you get more top end noise (from lifters, tensioner, etc) if the pressure is much below 20. On my 2001 1.8T, I've never seen the pressure below 23 psi, with the oil as hot as 215 or so. I wouldn't stress about what you should do in certain situations. Just get the readings, then make a decision afterwards. No worries yet. Like I said, most likely just a bad tensioner and the oil pressure will be fine.

I do not believe a faulty tensioner would have any affect on measured oil pressure.

The turbocharger helps to get the oil heated quickly, so I'd drive it around. It will take quite some time for the oil to come to temp by just idling it.

10-04-2010, 05:33 AM
Trying to find a gauge to do this...does anyone have a suggestion for the gauge to use? Did you just use a gauge that connects locally and struggle to read the gauge, did you use an electronice version so teh gauge can be remote or did you just run a long line? Also, does it affect the reading if the line tot eh gauge is not bleed? I know some gauges bounce if there is air in the lines.

ECS Tuning-Audi
10-04-2010, 08:12 AM
I can't give any input on the oil pressure gauge, as I have never used one personally, but here's a great write up on the use of one, as well as desludging your engine, and cleaning the screen in your oil pickup tube, which should be high on your to-do list, should you discover you do in fact have low oil pressure: http://members.cox.net/ambox/audi_sludge/

As far as your cam chain tensioner goes, walky_talky20 was correct, you need a revision K tensioner. We have one for $199.95:
http://c1552172.cdn.cloudfiles.rackspacecloud.com/101689_x800.jpg (http://www.ecstuning.com/ES2063671/?salesrep=PWinegardner&utm_source=audizine&utm_medium=forum&utm_content=PWinegardner&utm_campaign=postreply)

10-04-2010, 09:26 AM
Pete...great link thanks. Hopefully my issue is just the tensioner. Speaking of, I noted earlier in the thread that the K tensioners ranged from 200 to 700. One mentioned that the 200 is chinese made and that the 300 dollar version is an OEM. I am usually leary of chinese knock-offs but in reality almost everything is made there now, so can you provide any feedback on this particular manufacturer or where the other K tensioners are made? I don't mind spending a little more for better quality control but often this isn't the case and you really are getting the same thing.

10-04-2010, 09:26 AM
The gauge doesn't need to be a dash gauge, and you don't need to drive the car to test it. Just get the car up to temp, then connect the gauge and get the readings. The gauge most mechanics will have looks something like this:


Just a gauge that is temporarily hooked up to the engine to get the readings. Doesn't need to reach the cabin, but reaching the windshield is nice so you can see it as you are holding the engine revs at certain levels.

I opted to put a permanent gauge in mine (electrical, it uses a sender and just electrical wires run to the cabin). I was having some ticking after long highway drives and suspected oil pressure may be dropping *only* at those times. You are having the rattling whenever it is hot, so no need for a permanent gauge. Unless you want one. It is a good idea on a 1.8T because of the high chance of a clogged pickup screen.

This is the gauge I bought. I got it for about $50 (Or Best Offer FTW).
http://cgi.ebay.com/ebaymotors/Oil-Pressure-Gauge-Full-Sweep-Electric-Tinted-_W0QQcmdZViewItemQQhashZitem19b0ef450eQQitemZ11034 2653198QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccesso ries

ECS Tuning-Audi
10-04-2010, 09:34 AM
Pete...great link thanks. Hopefully my issue is just the tensioner. Speaking of, I noted earlier in the thread that the K tensioners ranged from 200 to 700. One mentioned that the 200 is chinese made and that the 300 dollar version is an OEM. I am usually leary of chinese knock-offs but in reality almost everything is made there now, so can you provide any feedback on this particular manufacturer or where the other K tensioners are made? I don't mind spending a little more for better quality control but often this isn't the case and you really are getting the same thing.

The $200 tensioner is not Chinese-made, but is not OEM. Our original equipment $300 tensioner is a more popular item, and is German-made. That tensioner can be found here. (http://www.ecstuning.com/ES1884226/?salesrep=PWinegardner&utm_source=audizine&utm_medium=forum&utm_content=PWinegardner&utm_campaign=postreply)

10-04-2010, 04:55 PM
Tried two auto parts stores on the waya home tonight...no one has an oil pressure gauge. Not what I expected, I thought I would find soemthing but maybe struggle with the M10x1 adaptor. I think I might pick up an M10 bolt and have it drilled out and tapped for an NPT fitting and work from that.

10-04-2010, 05:22 PM
This is the gauge I bought. I got it for about $50 (Or Best Offer FTW).
http://cgi.ebay.com/ebaymotors/Oil-Pressure-Gauge-Full-Sweep-Electric-Tinted-_W0QQcmdZViewItemQQhashZitem19b0ef450eQQitemZ11034 2653198QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccesso ries

How did you go about connecting the sender to one of the two ports? Need any extra fittings or does the sender screw right in? Thanks.

10-05-2010, 02:05 PM
How did you go about connecting the sender to one of the two ports? Need any extra fittings or does the sender screw right in? Thanks.

+1 tried a few places now and can't find one with an M10x1...would be nice if this just plugged in. Looked at modifying an M10 bolt and there isn't much room to adapt to something else. Also tried reaching out to a local member that works on Audi's to see if he can help.

10-05-2010, 03:12 PM
This is what I used to install an oil pressure guauge. It lets you keep your stock sender, plus add an additional sender with a M10x1 OR NPT fitting. My aftermarket sender has a npt fitting.


10-05-2010, 03:29 PM
For the hookup I used this M10x1 adapter (I got it cheaper off ebay):

And because my sender was large, I used a 1/8 NPT "street" 45 degree angle elbow (also cheap on ebay):

Of course some teflon tape on the pipe threads. I think I'll do a writeup at some point.

10-29-2010, 03:31 AM
Thanks again for the help...for anyone that ends up in this situation I recommend you just go buy a gauge kit or adaptor online. I tried a dozen different auto parts/speed shops and several hardware stores and found nothing. Found some fittings that might work, think it was a 3/16 NPT that threaded into an M10, but was afraid a leak would mean a seized engine. After a few days of screwing around I realized I was running out of time before I was going to have to go back to work and leave my wife with no car and a new baby so I brought the car down to KMD Tuning.

Turned out the oil pressure was marginal, they checked the cams and said they were clean (no sludge just varnish) with no signs of scoring so they recommended we replace the oil pump and pick up screen too. So in the end the timing belt, cam chain tensioner, oil pump, two engine mounts and some hoses were done. Still have some suspension work that needs to get done but with the new baby that expense has to be put off. Hopefully it will be good till spring and we can decide from there what to do after all the hospital bills come in.

ECS Tuning-Audi
10-29-2010, 05:19 AM
Glad to hear you got it sorted out - it's unfortunate you couldn't get your hands on an oil pressure gauge. Out of this situation, I have contacted our tools supplier Schwaben Tools and inquired about them supplying us such a tool. Apparently they have one in the pipeline and should be available in about two months.

In other news, it's good you didn't have any sludge. Congratulations on the new baby and hopefully your car will keep going like clockwork til you're able to get your suspension squared away.

10-29-2010, 06:21 AM
Thanks...we are pretty damn excited about our baby boy, funny how quick priorities change.

Good to hear about the gauge kit. My main issue was I had the damn gauge and just needed the adaptor and didn't want to buy a complete kit just to get a relatively inexpensive adaptor. But in hind sight should have just bought it, if my oil pressure was lower it likely would have caused damage driving it to get fixed. I just ran out of time and in this case may have gotten lucky. As for the suspension I have already checked out your kits, providing the car is running strong in the spring I will be picking one up. Luckily right now they are OK, just starting to see some cracks in the rubber.

10-29-2010, 05:21 PM
Glad you are getting this taken care of. What kind of oil pressure numbers did you get? If it was low, I'd expect the pickup screen to be at least partially clogged. Like this one:


I'd definitely ask to see the screen. And make sure you save your old cam chain tensioner. Sometimes the electrical solenoid can fail. If that were to happen down the road, you could swap your old solenoid onto your engine in about 5 minutes and be good to go (it is external). If you throw it away, you'll have to buy a new tensioner ($money$) and have it installed ($more money$). Just at tip, there.

Also, a "while you're in there" item for the oil pump would be the oil pump chain's tensioner. It is a little piece of plastic that is usually more wore out than you would like to think. I'd like to assume your shop would automatically replace it, but I'd mention it anyhow just to be sure. Here it is:

It should be noted that these items are 2001+ "only". This includes the solenoid on the VVT tensioner and the oil pump chain/tensioner. The earlier cars don't have a solenoid and don't drive the oil pump with a chain. Just for other 1.8T A4 guys looking at this post.