Schnell Gelb

Here is an easy job that if done in time can prevent the miserable task of removing broken exhaust header bolts and repairing stripped threads. I used search but could not find another similar thread so thought I'd make this contribution.
My rusty bolts came out unbroken after days of repeated applications of Kroil.Rap the head of the bolt with a flat face punch & hammer to loosen any corrosion .Repeat the Kroil. I then chased the threads with an M8 1.25 taper and then plug tap.See pic.
I had researched replacing the original bolts with s/s bolts/nuts but stumbled across a reasonably priced kit on EBay. Considering a set of Porsche stock bolts are almost $100, these upgrades seem a bargain?
The difference comes with the anti-seize. I prefer to use a high temp blue 2422(not red!) Loctite for the part of the stud that threads into the cylinder head. Keep the anti-seize for the part the flanged nut engages on. Over the exposed threads of the stud -beyond the nut , i put a dab of high temp sealant to reduce rust.
Here is the link to the std+nut kit.
http://www.ebay.com/itm/331119403899...84.m1423.l2648
In case it does not work just search on EBay for Jonsautoshack. NAYYY.
I hope this is helpful because some of the threads on removing broken manifold bolts are really awful!

Schnell Gelb

Here is an interesting thread that indicates the benefit of preemptively fitting s/s studs:
https://rennlist.com/forums/996-foru...lty-tools.html

terbiumactivated

I traveled this road on a 986, it's way cool that all your exhaust studs came out but from my experiences I would not be shocked one bit if preemptive snapping was an outcome on some cars.

extanker

i think i will leave mine as is

Schnell Gelb

There are other advantages that have been appreciated for decades on other engines.This is not a new idea,nor mine alone :
1.potentially higher and/or more precise clamping forces with the stud+nut than a mere bolt -& vitally no abuse of the aluminum threads in the cylinder head at the correct torque.
2. a serrated flanged nut is more secure and distributes the clamping force over a slightly larger area.A stud with Loctite 2422 on it is removable but will not shake loose with thermo-cycling or vibration.With the existing rusty steel bolt- not so much!
I understand that unless you've had to deal with snapped exhaust manifold bolts in a cylinder head, this upgrade mod is arcane.It is an easy job to do while your oil is draining.
I hope this helps others.

terbiumactivated

Unless one day the owner is putting headers on or the manifold gasket fails there is no reason to ever touch these the entire life of the vehicle. In the course of three decades over multiple brands most of the manifold failures I saw were from cracks and most times those were owner caused. Then, most would simply leave the resulting exhaust leak and call it good, boy nothing makes a car sound more like a pos than a manifold leak. What you ordered and put on looks cool and I'll take you at your word on the improvement, it's just the front end gamble I don't like, the it aint broke don't fix it thing.

Schnell Gelb

The unfortunate reason for removing the exhaust manifold is for an engine rebuild &/or cylinder head work as indicated in the Rennlist link in Post #2 above. It is 'verboten'(according to the manuals and expert advice) to rest the weight engine on the manifolds when you lower it on to a furniture dolly.

terbiumactivated

But if the engine is coming out and one snaps you have a wide open shot at fixing it whereas doing it during an oil change and snapping one would be a suck sandwich, just my two cents.

Schnell Gelb

I give up!

extanker

some po owners beezz funny

Schnell Gelb

Here is a photo of the old bolt vs the new s/s stud+serrated ,flanged nut.

sequel95

HI. Great thread. I plan to do the driver's side CV boot soon - as it is torn. Is it absolutely necessary to remove the exhaust header bolts to lower the exhaust to access the bolts on the inner CV joint?

I am selling car on BaT in the next few weeks, and want to wrap this up before the auction goes live. Or I just disclose it and let the buyer do this project along with the other side.

Thanks.

elgy

I did this when I swapped a spare engine in last year so that I could do my timing chain pads and some other maintenance without having to take the Boxster off the road for an extended period. Both engines now have stainless studs and brass nuts with SS washers.

bcrdukes

Hi @elgy Did you do the timing chain pads yourself or through a shop? If at a shop, would you mind sharing what it cost you? PM is fine. Thank you!