Lifter/ rocker knock when warm

B6/7 S4/RS4
#1

Forgive my rookie ignorance if any but here goes nothing. I’m usually able to find my answers on here somewhere but not this time. I posted on AZ as well but not with high hopes.

I purchased my 05.5 S4 being told that the timing chain guides were replaced along with one mechanical adjuster. The other was apparently in good condition. A good bit of time later my car developed a knock/noise near the rear of the drivers side valve cover but only when the engine was warmed up. I immediately assumed it was the adjuster as I could see the Bank 2 values jumping from about 8 to 15 or so at idle. So out came the engine. I found all the guides and one adjuster new. The other adjuster looked slightly worn so I tossed a JHM sprocket on there. Everything else looked good so the engine went back in along with a few new goodies. Initial startup went perfect with no rattles or noises. I get everything bled and took it down the road just to hear the very same rattle a few minutes later. The adjuster values are better than they were but still a little off from bank 1. At this point I can only assume it has to be a lifter or rocker but I’m puzzled because it sounds perfect when the engine is cold. I wanted to get eyes on so I ran the engine up to temperature and pulled the valve cover. Everything looked good and tight so I fired it up. Oil flow looked good everywhere but from one side of an exhaust rocker. The oil was squirting out at an angle compared to the rest. In addition, I did not hear any knocking in the few minutes it was running and it normally would at that temperature. I put some seafoam in with the Mobil 1 0w40 and idled for about 30 minutes, drained it, and replaced with Liqui Moly 5w40 to observe no change after a 20 minute drive. I did some logs before and after. The cam values look to mirror each other at higher RPM’s but not at idle. But then again, I didn’t look at the numbers until I had an issue so I could be missing something.

So I’m confused as to why this would only happen with hot oil and why it didn’t sound off when the valve cover was removed. Do I have an oil pressure issue and would the pcv system have any influence on it? Is there a way to identify a bad lifter without pulling the rockers off?

This video is not mine but his engine sound almost identical.

https://www.youtube.com/watch?v=4gRq…I&spfreload=10

#2

Welcome to the forum good first poist that’s a big issue. Its always hard to nail down noise things. They can be tricky.

Sounds like you walked down the proper path to find where this is coming from. Without really getting into it there is a possible chance that once the oil thins out the lifter starts making noise.

Now I have worked on several cars where if you let the motor sit for several days the lifters would colaps and it would take a long time for them to come back up but generally those are only when the motor is cold.

After you did the seafoam did you see any difference in the one area where the oil was not coming out smoothly

#3

Thanks Justin. You’re the one person I hoped chimed in.
I was driving the car every day when it started knocking so it wasn’t an issue of it sitting. I had no issue at all after the oil check valve replacement either until it warmed up. I have not pulled the valve cover since the seafoam treatment but I will at some point to have another look. First I need to know if there is anything I can visually see to narrow it down to in fact a lifter. The more I research the more I wonder if I didn’t overlook a bad chain tensioner while I had the back open. My heart was set on the adjuster as my culprit and I had confidence in the previous owners work. My cam phases are (B1)-1 and (B2)-2. And B2’s adjustment values seem to wander a bit more than B1. Is this normal? Do you recommend I pull the cams and inspect each lifter? I’m pretty lost as to what direction to go at this point.

#4

That’s a hard road to walk down. Obviously it would be better to not have to pull the motor. I think the big game your going to have to play right now is working to get to the bottom of what is actually making the noise.

If you can drive the car and its not missfireing then I would really strongly lean against it being a lifter as if the lifter isn’t staying pumped up your going to tend to see misfires.

So questions like do you hear the nosie at idle… will it get worse if you rev the motor or hold rpm.

Cam phase adjustments are hard to call it could be the variance in the chain or just an over active unit from oil differences.

#5

I can drive the car and put about 30 miles on it today. I’m not having any misfires at all. I did pop a code for B2 S1 too rich this afternoon.

I do hear the knocking at idle but at random times it’s not there. I can’t tell at higher RPMs as the exhaust drowns everything out but it does sound like it smooths out.

#6

Hard call.

If its hit and miss I would say that’s better than it being all the time. Obviously you will be able to learn more if you can investigate further but I would do that by trying to keep an ear open to how and when it happens and if you can duplicate the noise at will. If not then just trying to localize it best you can. but for now I would so no misfires and no cam codes is a good start.

#7

Does anyone have a diagram of all the oil passages? I might pull the supply tubes to the rockers but I would like a better understanding of the flow paths first.

I’m also considering maybe a sticky solenoid restricting flow to the adjuster. I’m going to hit it with the 12v trick to see if that changes anything.

#8

So of note, I drove the car to work this morning. Sounded perfect on startup but sounded like hell by the time I got to work. I shut the car off and used the clear codes function in VCDS (didn’t have any codes). I immediately started it and it idled perfect. So because of the p2198 code I’m popping after about 20 miles I think I have a vacuum leak of some sorts but I have no idea why clearing nonexistent codes quiets the engine. I’m a bit ignorant on fuel trim values but doing this resets them right?

#9

Yes clearing codes re sets the ECU and with that all fuel trim data.

But you said clearing codes helped the car run better?

#10

When I shut the car off and clear the codes the knocking goes away and the car runs very well for a short time.

I think I may have a partially plugged oil passage in my electronic adjusters or head. I did find some tiny chunks of chain guide inside my mechanical adjuster when I pulled it apart.

So my plan of attack this weekend is to pull the cams to inspect the lifters and pull the mechanical and electronic adjusters to see if anything is in there.

#11

Something is up. If you clear the codes and the car runs better there sounds like it might be more vac related. or something maybe not directly connected to the timing as I don’t think the timing parts are going to be effected by clearing the codes.

Next time you get the car running and it starts to act up pull the MAF wire off and see if that helps stop the noise.

#12

So maybe I have more than one issue at play here. Additional problems worth noting are a groaning fuel filter that I’ll swap out this weekend and an exhaust leak on the opposite bank as the knocking.

I warmed up the car this morning to induce the knock and pulled the MAF connector. I observed little change and the knocking remained. I plugged it back in and the car died. I cleared the codes from the sensor and started it back up and the knocking was gone. Below are links to videos I took before and after the code clearing.

https://www.youtube.com/watch?v=CQiI_0PfvkY Before clearing - knock present
https://www.youtube.com/watch?v=hPFnUZSn2as After clearing - no knock

Is it normal for the cam phase position to change? Mine has moved around from -1 to -3.
Any other measuring blocks I can check before I pull it apart?

#13

So I pulled my engine back out. Cams and rockers are out. Lifters all look good except a few that have gone soft from sitting for a few days I’m assuming. None are crushed or sloppy loose.

One thing of note is the main timing chain is very loose on top. To the point where it has marked the block above the top center guide. I have linked a video of it below. The tensioner for that chain seems much weaker than the others but looks new. The chains also have little to no wear so I don’t suspect it has stretched.

https://www.youtube.com/watch?v=BIDU5ch_aT8

From here I think my problem may be the main chain tensioner or oil supply to it. I’m considering pulling the oil pan while it’s out to see how things look in there.

#14

Nobody has any input on this?

#15

I watched the video and then had to take a few days to pull off the back side of a stock mid mileage motor I had here at the house. My 70k mile motor has the chain much tighter than that. I would have to imagine that would certianally be part of your issue if not the possible bulk of it.

#16

Thanks for pulling that apart and taking a look for me Justin.

I looked everything over timing related and the only thing i could find was a missing o-ring on the main chain tensioner. I guess this could explain loss of pressure if the oil was bypassing when hot. So I put everything back together, primed the oil system and started it up yesterday. The racket was terrible and I attributed that to the lash adjusters taking some time to come up. After a few minutes ALL of the noise stopped and it sounded smoother and quieter than ever. Gave it some small revs and it sounded perfect. This only lasted about 30 seconds and the racket started again. At this point the only conclusion I can draw is that I’m losing oil pressure somehow. I have no oil pressure light on. So either the switch is faulty and I have a pump issue or I have a blockage after the switch.

Today I’m going to test the oil pressure then pull the oil pan off to inspect the pickup and possibly the pressure relief valve if I can find it.

#17

Ran the oil pressure test. Results were normal. Below is a link to a video of how it currently sounds. It did not go quiet at all in the few minutes I ran it.

https://youtu.be/wGTrcON9zy4

At this point, I think I just need to find a low mileage engine. If anyone has or knows of one let me know.

#18

If anyone is still following this It’s the end of the road for this engine. For now at least. I scoped the cylinders and the valves contacted the pistons in cylinders 7 and 8. After pulling it out and tearing it apart I found the chain tensioner flat and the cam adjuster not locked so it appears I lost all oil pressure to that side. There must be a blockage somewhere. I will continue to tear it down and try to find a culprit but for now a new engine is on it’s way.

Justin, thanks for all your help. Your input on the forum is much appreciated.

#19

chuck there are several people readying this still. I’m one of them. Keep us posted on this buddy… so sorry to hear about all of this. Good attitude and great updates. The more you know the more you are in control and taking the mystery out of the car.

#20

Bought an engine that was supposed to have been professionally rebuilt. Turns out a toddler did it and not the shop that was claimed. I’m at fault for not getting all the documentation up from but I was rushing what I thought was a good deal. I highly doubt I’ll get my money back especially since the coward won’t respond to any communication. So I think I need to take the two engines and make one as the new one has rebuilt heads and supposed to have new rings and bearings. That’s yet to be confirmed. The cylinder walls on the new one are trashed from when he blew it up and tons of parts are missing.

So I’m looking for anyone with experience installing internals to give me some pointers and what to look for if I decide to merge these two to make a good engine.