Tapping/Ticking noise from engine

[Anders93]

So, I've got a new (fairly) loud tapping noise coming from my engine (MY 2003 with 132,xxx miles). The story is - I'm driving along and notice this fun new noise in front of me. A couple seconds later, I get a SES light. Code is for cat efficiency. Well, I installed some megan headers about 200 miles ago, so I figure maybe I didn't tighten them up enough. Turns out cylinder 3 is missing an exhaust gasket... which I found in pristine condition laying in the under tray. Not sure how I managed that one. Anyways, I pop off cyl 1-3 manifold, slap on the gasket, fire it up, and to my dismay the tapping is still there. I think, well it would be super coincidental, but maybe the valves need to be adjusted. I overnight a shim kit and VCG (btw, FCP Euro has a great sale on overnight delivery right now). Many of the valves are pretty far out of spec, some by as much as 0.05mm! HA! That's got to be it! Get everything within spec, button it up, fire it up, and I guess you know the ending because I'm posting this here. Same noise coming from the same area. Ok, GREAT. Don't panic. Woosah. This is what I know/did so far:

- Taps during idle and revving, increases frequency with increasing revs
- Taps warm or cold, temperature does not affect sound much if at all
- Taps with and w/o clutch engaged
- Valves are in spec (mentioned above)
- Cam bolts are good
- Vanos exhaust hub is fine (all beisan parts)
- Removed and re-torqued spark plugs - no change
- Used a screw driver in spark plug hole to push down on piston on down stroke to check for rod bearing slop - no discernible play, but I've never done this before. It doesn't sounds like rod knock either, at least from youtube videos I've heard.
- Using a breaker bar as a stethoscope, the noise is loudest near cyl 3-4 exhaust manifold, but it's not SUPER obvious that it's coming from there like when I put the bar on the injector rail or vanos housing and all I can hear are the injectors ticking or timing chain.
- Rocker arms moved freely in their seats
- When I had the valve cover off, I noticed a fair amount of dark crustiness on everything in there. I also noticed some wear patterns on the cams/rockers. I snapped a couple pics, and was wondering if this was abnormal. Should I replace rockers if I want to do cams down the line? The "weirdest" pattern is cyl 3 exhuast (first 2 pics).

When the engine cools down, I'll pull the headers gaskets and take a look for signs of a leak - maybe the gasket didn't seat correctly or maybe reusing the other 200-mile-old exhaust gaskets was a bad idea. In the meantime, I'd be interested in hearing other things to try and rule out.

Video of the sound is here:

[Tbonem3]

You pushed down on a piston with a screwdriver?

A bad headgasket ticks, I've read.

[stash1]

Have you tried starting w/a cold engine and then immediately feeling around the exhaust ports for an exhaust leak...you may need several attempts to get to all of the cylinders before it gets too hot-lol.

[beefaroni]

It seems to tick about 13-14 times per second which matches up with the ~800 rpm idle speed so to me it is not top-end related. Is it more on the exhaust side than the intake side? would it make sense to remove drive belts to isolate any accessory noise?

[Anders93]

You pushed down on a piston with a screwdriver?

A bad headgasket ticks, I've read.

Yea, like this, except I couldn't fit an extension because the spark plug holes were too small. Went with a screwdriver.

[Anders93]

Have you tried starting w/a cold engine and then immediately feeling around the exhaust ports for an exhaust leak...you may need several attempts to get to all of the cylinders before it gets too hot-lol.

Haven't tried this yet. It'll put it on the to-do list.

[Anders93]

It seems to tick about 13-14 times per second which matches up with the ~800 rpm idle speed so to me it is not top-end related. Is it more on the exhaust side than the intake side? would it make sense to remove drive belts to isolate any accessory noise?

That's a great observation. I put a high-pass filter on the audio which let me basically count the ticks. It ticks about 10 times/sec.

It seems to be more on the exhuast side, although it could be because that's the side that's more accessible. Just from being under and over the car, it really doesn't sound like it's coming from the front at all. More so from the middle of the engine if that makes sense. I'll add this on the to-do list for when it stops raining.

[Anders93]

Took the s-belt and AC belt off for a quick second, but the tick was still there.

Also, manifold gaskets looked fine, although I probably over-torqued the bolts cause parts of the gaskets stuck to the headers. I have 6 new gaskets coming tomorrow. Going to pray that is the issue, but I'm not getting my hopes up at this point.

[beefaroni]

My car is a bit noisy on the exhaust side, mostly throught the wheel arch just like this video here. This noise is normal to me. Yours does sound louder. The simplest answer is usually correct. It seems to coincide with your recent exhaust work.

fingers crossed

https://m.youtube.com/watch?v=MHaSMrSDvZ4&feature=youtu.be

[heinzboehmer]

My car is a bit noisy on the exhaust side, mostly throught the wheel arch just like this video here. This noise is normal to me. Yours does sound louder. The simplest answer is usually correct. It seems to coincide with your recent exhaust work.

fingers crossed

https://m.youtube.com/watch?v=MHaSMr...ature=youtu.be

Mine sounds almost exactly the same as this. Can also be heard louder through the passenger wheel well.

[beefaroni]

Call the dealer with your VIN and have them check to see if the DME has been reflashed to take care of the Cat efficiency threshold being too sensitive. I would get that code once a month until the dealer did the recall. Had them do it at the same time as the Takata airbag recall

[AdamM3]

When you adjusted the valve lash, did you take a look at the rocker arm contact area. I have seen cars that make a similar noise and some of the rocker arms were flattened out. Even if you shim to the correct clearance, they will still make noise if they are flattened out. Hopefully its just something to do with your header install.

[BMWahba]

Mine sounds almost exactly the same as this. Can also be heard louder through the passenger wheel well.

Mine sounds like that when it's hot too. Video in OP does seem more pronounced.

[Anders93]

Call the dealer with your VIN and have them check to see if the DME has been reflashed to take care of the Cat efficiency threshold being too sensitive. I would get that code once a month until the dealer did the recall. Had them do it at the same time as the Takata airbag recall

I'm actually running CSL software, so I wouldn't want to do that. However, there actually was an exhaust leak previously when I forgot to put in the cyl 3 gasket, so I'm pretty sure that caused the code.

When you adjusted the valve lash, did you take a look at the rocker arm contact area. I have seen cars that make a similar noise and some of the rocker arms were flattened out. Even if you shim to the correct clearance, they will still make noise if they are flattened out. Hopefully its just something to do with your header install.

I did not do that. I was actually just thinking about that after watching this video this morning:

I'll check this out if the new gaskets don't work. I do have some pictures from the cyl 3 exhaust side cam and rocker arm (pics 1 and 2 in the OP). There is a wear spot on the cam and arm. Would that be enough to cause a noise like that?

Mine sounds like that when it's hot too. Video in OP does seem more pronounced.

Yea, my car used to sound very similar that (before the new tap noise). I realize these engines aren't exactly quiet, but this new tap noise is definitely new and very pronounced. I can actually hear it pretty clearly from inside the vehicle.

[Redline]

If the noise wasn’t there prior to install then it may be a result of the work performed. That said the steel on some aftermarket headers are thinner and will result in a normal ticking noise.

s54’s tick, I have two sitting in my driveway that have some degree of a tick on the passenger side. Some engines are louder than others When it comes to s54’s. If rockers are good and valve clearance is good and no signs of scoring on the cams/rockers I’d say you are g2g.

and I saw head gasket was noted. Only in the ok they have this issue and the tick is a ping (detonation) when lightly rolling into the throttle at low speed. Not this.