Mitigating broken exhaust header bolts - Cargraphic headers on the way

Hey all, Preparing to install a set of new Cargraphic headers to complete my exhaust - currently have Cargraphic Super Sound mufflers and Cargraphic 200cel x-pipe so wanted to finish it off with the headers. My car is a 2004 C2 - Australian delivered so rust isn't really a thing here thankfully! Anyway I did read once that Jake @Flat6 Innovations had a recommended procedure for successfully removing the bolts that was (from memory) and please correct me if i'm wrong: - Spray down bolts with WD-40 / PB-Blaster etc - Drive to heat up exhaust - Re spray with WD-40 / PB-Blaster etc - Remove bolts Anyone have any tips on trying to prevent broken exhaust bolts? I already have a set of brand new genuine bolts and new genuine gaskets also the headers to x-pipe already have new bolts - replaced them last time. Might replace them again just because. Also any recommendations/warnings on tools to use/not use? I have most sizes in hand tools (1/4, 3/8/, 1/2), AEG battery 1/2 impact wrench and 1/2 air rattle gun lined up for this. I'm going to vote out the rattle gun as its too powerful - thoughts on battery impact wrench? Or just undo them by hand with a 3/4 ratchet? This is for undoing the bolts - I will be doing them back up with only my torque wrench. For reference tightening torque is 19ftlb. Thanks!

I have a tool that fits on an air hammer that you can fit an impact socket on that works great for rusted exhaust bolts. Other than that, I would use hand tools. Less likely to break a bolt working by hand otherwise.

I like to use a 3/8 drive battery impact gun with 25-35 lbs torque. (Some of the 3/8 are much higher). The impacting action helps to loosen stuck/rusted bolts/nuts where a hand/constant pressure will be more likely to twist the head off.

Luckily they don't look too rusted so I'm hoping that I'll have an easy time removing them. Ahh a good point maybe ill use the AEG battery impact gun on the lowest power setting + hammer action. I should read the instructions it came with haha.

If it doesn't come loose easy,, Repeat,, - Spray down bolts with PB-Blaster etc (I dont bother with WD40 its a poor penetrating oil) - Drive to heat up exhaust - Re spray with PB-Blaster etc. - Use a can of circuit chiller , put a deep well socket over the nut and spray inside it. (Use a shop rag to prevent blow-back) It will chill the steel and shrink it which often breaks it free.. - Remove bolts

Thanks everyone, I'll have to source something better than WD-40 as I don't think I can get PB blaster here in AU I've just read about it. Circut chiller is an interesting one!

I learned about it working on friends boats and planes.. Friend in the military with me years ago was the guy who repaired the skins of the planes.. Was constantly having to get broken screws out without damaging a million dollar skin.. Same guy could cut a pop can in half and tig weld it back together.. Mad skills..

Awesome, thanks

Think I found PB blaster, is this it: https://www.ebay.com.au/itm/PB-Blast...-/152627004535

^What those guys said! wd-40 is a water displacer, you want a penetrating fluid. I prefer PB blaster over anything else (just don't get it in your eyes!!). I have never had a 996 exhaust bolt break (in a small sample size). I use PB Blaster and a electric impact gun, and they have always come right out. This always shocks me, because every other vehicle I've done this on, exhaust hardware is a pain: rusted, rounded off, snapped, etc.

I'm in the NE US (lots of road salt) and my car originally came from the Midwest (Chicago area - lots of road salt) - everything looked horribly rusted. All the header to block bolts came out perfectly - using nothing but hand tools (3/8" ratchet). The same can't be said for the rest of the exhaust system - had to replace most of them (even the ones that did unscrew) and use all sorts of nut extractors etc. Anyway, my point is - yes, use the penetrating oils/solvents etc. but don't stress prior to trying to remove them...chances are they'll come right out without problems... Good luck

Thanks everyone, I've read so many horror stories on here about broken exhaust bolts and that's the last thing I want! Think ill just gauge it when im under there - either remove them with the battery impact or 3/4 wrench. Also going to order some PB blaster - found a source here in AU I'll keep everyone posted!

Be careful reinstalling the header to head bolts. One on each side is hard to get a straight shot at and easy to cross thread. Let's see those headers!

Thanks, have seen that access to them isn't the best so see how we go! Yep I'll post some pics soon as they land should be a week and a bit - coming direct from Cargraphic in Germany

Quotes source post: 16015652

Horror story here. I snapped 3 bolts while removing my manifolds to install Cargraphic headers. And my car was a CA rust free vehicle. It sucked. I had to drill out and put in timeserts. Very tedious and time consuming. Not trying to jinx you, just making sure you are prepared. Hopefully yours will come out clean. Best wishes my friend.

Quotes source post: 16017431

Thanks, I don't like the sound of that at all!! I've just bought a can of PB blaster. How did you find the headers?

Quotes source post: 16017450

Hopefully you will not experience any problems. This was a few years back. My friend ran Stuttgart Performance and RSS in Costa Mesa, CA. They were the US sales rep for Cargraphic products in the United States. I did the entire exhaust system. Headers, 200 cell cats, and sport mufflers.

Ahh I see, I didn't do the headers just the mufflers and cats at the same time. Finally decided to complete the system with the headers. I'm going to be liberal with the PB Blaster - wish me luck!

Quotes source post: 16017459

I do wish you luck. And hopefully everything will work out. Its not really rust that causes the problem its heat which basically sears the bolts in place. So yes go crazy with the PB for a few days..

Thanks ill spray them down when it arrives and leave it for a few days. Might be hard seeming they are upside-down and fighting gravity.

Quotes source post: 16017469

Lol. Yes. Get a little wire brush and work it around as much as possible. Let us know how everything comes out..

Will do - I'll keep everyone posted hopefully with good news!!

Guys any tips on the block to header gaskets? The new genuine gaskets seem to have a small tab on them? Assuming the tab sits into the block as the tab can't face the headers? Also for torque reference for the header bolts: 19ftlb Should I use some Castrol Optimol anti seize paste too?

Sorry no answers for the most recent questions but i gave some input on the removal. Remember that heat can be your friend. If you feel that the bolt wont back out without breaking, hit it with some heat from a map gas torch. I have had to heat cycle exhaust bolts 2 or 3 times in some cases.

Thanks, was going to drive my car to heat up the block to heat up the bolts a bit then try them before it totally cools down.

Quotes source post: 16018717

Yes, your old ones will show you the way. 17-19# Yes. Also, a dab of copper exhaust gasket to hold the gaskets to the header before installation will help as the gaskets fall/slide out of place all to easily. Use eye protection too!

Good luck. My car was originally a New Jersey car and had some rusted bolts and brackets when I got it. I had three bolt heads snap off on the exhaust manifolds. I would second the recommendation for a low torque impact gun to try and knock them loose. If you do end up breaking any this tool is what you need. It worked perfectly for drilling out the rusted bolts without damaging the threads. https://www.stomskiracing.com/produc...olt-repair-kit

Thanks - one very expensive tool with the AUD being so low In good news the headers arrived on Friday but the PB blaster I ordered only arrived today so ill give this a shot over the weekend. Pics! Works of art - shame they can't really be seen! This can of M'erica arrived to me today! Work it like a PRO! Yeaaaaaahawwwww haha

I put a set of 997.1 Tuby Style headers on last week, very positive feel on my first drive.

Nice one Bill - did you install them yourself? Also need the forums advice - my AEG cordless impact has a few settings: Low torque: 70Nm (51ft-lb) Medium torque: 120Nm (88ft-lb) Maximum torque: 160Nm (118ft-lb) Speed mode 3: 300Nm (221ft-lb) Speed mode 2: 170Nm (125ft-lb) Speed mode P: 58Nm (42ft-lb) Assuming the higher modes are out, thoughts on 70Nm (51ft-lb) vs 58Nm (42ft-lb)? I'm guessing speed mode might just rip the head right off so leaning towards 70Nm (51ft-lb). Sorry to go on and on about this but the last thing I want is to be staring at a broken bolt quietly weeping under my car... haha

Quotes source post: 16033301

Yes I did. Your over thinking/ worrying...I had no issue with two different motors. I also like the old manual hand Hammer Wrench in these applications..

Next time just mix Automatic Transmission Fluid with Acetone in equal amount and use that as penetrating oil. It's better than anything on the market. You don't have to take my word for it, just Google it.

Quotes source posts: 16033672, 16033968

What's a hand hammer wrench?? Interesting... Thanks I'll check it out already have the PB blaster which is convenient to spray this time around

Most definitely overthinking it... I'll report back

Hand hammer wrench is a socket driver that you put your socket on, put over the screw and then smack with a hammer whilst turning lefty loosey. It will, ideally, shock the bolt loose. Cheap at Harbour Freight if you have that store. The best penetrating oils I have used are from Kano Labs. Industrial stuff. Mail order. Order the product called Kroil.

Quotes source post: 16035145

I thought that was called an impact driver or impact screwdriver.

Quotes source post: 16035252

Yes, I was blanking on the correct name (been over 30 years since I bought one) and you all figured it out.

Okay so update! Sprayed down the bolts with PB blaster - geez that stuff smells strong. Thought I'd give it a shot - got 4/6 bolts on the left header out. The remaining front and back were stubborn and I have to lift the car up to get a longer extension on them so I left them for tomorrow. So far the cordless impact has done a great job. The bolts that came out look to be in good condition - although I'm replacing them anyway.

Those are some weird looking bolt heads!

Quotes source post: 16042583

Haha really?? They are the OEM bolts.

Quotes source post: 16042585

In the land of OZ that is...

According to Auto Atlanta, the '02-'05 (M96.03) use the 99907507100 which looks like the one posted above. The earlier cars (m96.01/02/04) -'01 use a 90037813100, that looks like a regular bolt. Oh, and I don't know whether this is useful advice, but when you removed the other bolts, you may have made it more difficult to remove the remaining bolts. I like to crack seal on all of the bolts, then once they're all broken loose, remove them. This probably has nothing to do with your situation. But, if you are concerned about it, you could put the other bolts back in to relieve any tension.

Quotes source post: 16042487

I replaced mine with titanium versions: strong, light, highly corrosion-resistant and not too crazy expensive.

Quotes source post: 16043255

....and a total waste of money.

Are they in yet? I found it easier to use a 1/4 drive and extension for the bolt next to the water pipe. Don't over torque either.

Quotes source post: 16043465

I felt that significantly reducing the chance of another remove-the-stuck-bolt siege was worth $18 (titanium bolts cost me ~ $1.50 each on eBay). YMMV. Note that some sources charge that much and more for OEM bolts.

VICTORY! All 12 out without any broken! Thanks for everyone's input - next job is to fit them! ​​

Sweet!

Nice work!

Quotes source post: 16044778

Awesome job. I am so glad that it worked out easily....

Thanks! Got them installed yesterday, quite a tricky job if you dont have a hoist! Managed to get them on Just have to shift the xpipe slightly right to re assemble.

Looking good, post a sound clip when its all done.

Will do! One noticeable difference so far is the weight the Cargraphic are much lighter. Also additional notes as per Bill's recommendation - needed a thin 13mm socket on the bolt near the coolant line - when getting the bolts back on a wobble extension was invaluable! Also needed a deep socket 13mm for the rear bolt on the LH header. This is not a job I ever want to do again! Haha - thanks for all the support on my overthinking!!