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Discussion Starter #1
Hi fellow Alfisti,

My car runs great but I've noticed the ticking noises under the hood have been getting louder and louder making me a bit paranoid. I've used a mechanic stethoscope, hoses, cardboard etc and I'm unable to pinpoint anything and sadly I don't have a video of the engine running to share but I can confirm the valve clearances are within spec as is the timing chain adjustment (Cold measurements below).

INT EXH
1 .0157 or 0.40 .0188 or 0.48
2 .0157 or 0.40 .0188 or 0.48
3 .0169 or 0.43 .0188 or 0.48
4 .0169 or 0.43 .0196 or 0.50

Background
I'm running a 4 into 2 Cast Iron header on my S3. The conversion was done in a rush many years ago (the exhaust system is not pretty) but it does retain the CAT and O2 bung etc. Last year I replaced the copper gaskets for both the headers and the down pipes. I also replaced the nuts with 12mm brass nuts and non-locking washers. The 12mm nuts are great, they allow much easier access making the occasional re-tightened super easy (curved 12mm wrench also very helpful).

I was already planning to pull the exhaust for better access to the Giubo/Center Bearing so I figured now was a good time to see if I can nail down these leaks and put my mind at ease.

Removing Exhaust/Headers
When I pulled the exhaust from the down pipe I noticed a small carbon line on the copper gasket and a bigger line on the header flange. Certainly this is the source of my ticking noises.

Headers IMG_6424 copy.jpg Downpipe IMG_7865.jpg

Before unbolting the headers I decided to remove the 2 heat shield bolts above Exh #1 and #4 to see if they might be another source for the ticking noises. They weren't flush with the flange but I still thought they were in there permanently. It took some effort and penetrating liquid but thankfully they backed out without breaking. Sure enough the threads and washers are corroded with rust and covered in carbon leading me to believe this is another likely another source for my ticking noises. I searched the board and I'm not sure these bolts holes are stock as they do go all the way thru and into the exhaust.

Bolts IMG_7864.jpg Bolt Holes IMG_7846.jpg

Bolts after soaking for a few minutes in distilled white vinegar.

Oil on #4IMG_7836.jpg Carbon and Oil IMG_7840.jpg

When I pulled the cast iron headers I noticed a decent amount of oil around the bottom of the #4 copper gasket and a few minor carbon spots.

I was aware of the head gasket leak but didn't think it was all that bad. I plan to do a cold lubetorque in the hopes it will slow the leak. The valve cover, half moons etc have been ruled out as a source and I know I will need a head gasket soon, I'm just hoping it can wait till next year.

Here's where I could use some advice.

Heat Shield Bolts

I'm not sure what to do about the heat shield bolts. I'm not convinced this is the stock setup, I've seen some pics that show a bolt with a built in spacer that I presume keeps the heat shield from touching the headers (FYI: I don't have the S4 heat shield that bolts to the headers). And while I'm pretty sure I can find some grade 8 bolts at the local hardware store, I'm certain they'll be way too long. I suppose I could cut them down and use the same washer I'm using for the header bolts, (not a lock washer) but I wonder if that'll be good enough to prevent leaks. Should I add some sealant, locktite? Got any recommendations for this rather warm location?

Gaskets
I'm also thinking because of my unique (haphazard) setup it might be worth adding some sealant along with new copper gaskets at the headers and down pipes. I'd really like to try the one piece mesh and graphite HD Gasket that's out of stock at Centerline, it's thicker and looks like it would compress into the irregular surfaces better.

What variety of sealant do you think would work best with the copper gaskets, cast iron headers and heat. Maybe I should make my own gaskets? I've heard some stack 2 copper gaskets. I'm open to suggestions.

Oil Leak
After doing the cold lubetorque should I add a bead of sealant around the leaking gasket? I'd clean it with brake clean first and let it sit overnight before applying sealant. I've read that it may help delay the inevitable head job but I'm not sure which of the 9,000 varieties of sealant I should try.

So far I am leaning towards the 1 version I don't already have: Permatex Ultra Copper Gasket Maker.

Thanks,

C
 

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obviously your S3 never had a heatshield (that was only the S4 and even there only the later models with the cable throttle set up had one)
Originally it is just a threaded Boss for the heatshield and no, it wasn't through drilled.
Plus the mounting boss was on cyl #1 and cyl #3 (so one boss on each manifold)

Your exhaust 1&4 is likely a replacement coming from a set that someone has drilled, perhaps for exhaust gas temperature sensors, or something like that.

the fairly big carbon leak on that 3 bolt flange is, I agree, almost certainly the ticking noise. There were gaskets there hopefully? (you do not show them)

The 2 manifold outlets look like they have a tiny bit of carbon leakage...were the copper nuts tight, or didn't you test before you undid them?
Sometimes just a slight tighten up solves that one...plus new gaskets.
your second photo shows one gasket the correct way round and one the wrong way (presume they were not bolted to the head like that?)
the flat edge runs along the head join.
exhaust gasket tip.jpg

On the flange you can use any decent exhaust assembly paste from your local auto shop...Permatex, Würth, Sealey, Hylomar etc, they all do them.

I'd just reuse the bolts you have, clean them up as best you can with a wire brush and use bit of the same sealant on the threads.
Can't make out if that's a copper washer on those, or part of the bolt. If a copper washer then get 4 new ones.
 

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They are not bolts for a heat shield. They are taps for testing the CO on each cylinder.

Alfa had a tool that hooked up to a co machine. You would pull the plug and insert the tool to read the CO.

There is suppose to be a copper crush ring under the bolt head.

So your manifolds are correct. No one but the factory has drilled holes in them.
 

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Discussion Starter #4
Thanks for the replies.

Yes, the nuts were tight all the way around. I had just re-checked them the day before pulling off the headers. Yes, the down pipes had new copper washers that are now flat as a pancake.
Keen eye! You're right the gasket in the photo, the one not covered in oil, is not oriented correctly, I was trying to show the carbon marks on that side of the gasket.

Makes sense that the two bolts were for sensor equipment. The headers were purchased new (I think) from Alfa Parts in Berkeley many moons ago, I'll reach out to Jon to see if has the crush rings.
 
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