What does an exhaust leak sound like?

[mooshu47]

Finally got a chance to get under it. I'm still baffled! heh get the pun right?

Soo, wow. I wonder what is causing this popping noise from my header? Could it be some kind of exhaust leak?



Yes, I do feel very stupid. And yes I did put that nut on but it apparently fell off. I blame my 20 year old torque wrench.

[Tcoat]

Originally Posted by mooshu47

Finally got a chance to get under it. I'm still baffled! heh get the pun right?

Soo, wow. I wonder what is causing this popping noise from my header? Could it be some kind of exhaust leak?



Yes, I do feel very stupid. And yes I did put that nut on but it apparently fell off. I blame my 20 year old torque wrench.

Always re-torque header nuts after a few heat cycles. If not they... welll... fall off.

[mooshu47]

So yeah I re-torqued everything and car is happy. For anyone who cares, I got some video of before / after the leak. (2 nuts are missing in the vid because I had to take one to the store to get a replacement, but only one fell out originally.)

Anyway:

(with the leak)

and

(without)

[Tcoat]

Originally Posted by mooshu47

So yeah I re-torqued everything and car is happy. For anyone who cares, I got some video of before / after the leak. (2 nuts are missing in the vid because I had to take one to the store to get a replacement, but only one fell out originally.)

Anyway:

(with the leak)

and

(without)

Yep so in a couple of days torque them again. And then maybe again later. I have lost my share of nuts over the decades.

[humfrz]

Originally Posted by Tcoat

Always re-torque header nuts after a few heat cycles. If not they... welll... fall off.

What ever happened to the use of lock washers -


humfrz

[juniorrr]

Anyone know the torque specs for the Header itself and then the torque specs for the connection point from the header to the Over Pipe?

[mooshu47]

Originally Posted by juniorrr

Anyone know the torque specs for the Header itself and then the torque specs for the connection point from the header to the Over Pipe?

According to my experience, gorilla. No but I did search far and wide and it seemed to be common for the 6 nuts attaching the header to be at 22 ft/lbs and the 2 bolts from header back to be between 26-30 ft/lbs. DO NOT quote me on this. If you follow my advice your entire exhaust system will FAIL. I dunno ask a Subaru technician or find a proper shop manual.

[Tcoat]

Originally Posted by mooshu47

According to my experience, gorilla. No but I did search far and wide and it seemed to be common for the 6 nuts attaching the header to be at 22 ft/lbs and the 2 bolts from header back to be between 26-30 ft/lbs. DO NOT quote me on this. If you follow my advice your entire exhaust system will FAIL. I dunno ask a Subaru technician or find a proper shop manual.

37

https://demos.starbase7.net/t3Portal..._rm_index.html

[GrimmSpeed]

Originally Posted by humfrz

What ever happened to the use of lock washers -


humfrz

Whatever happened to the use of lock washers? Well, sometime around the 60s lock washers were actually found to aid in loosening joints rather than keep them tight. They've pretty much been a joke ever since in professional communities, and if you see a lock washer on something there is a pretty good chance it was designed by someone who could use this information. The ONLY potential use for a lockwasher would be the preload added from a nut that has already come loose. However, even in that instance, if the joint is becoming loosened by relative motion the lock washer isn't going to save it, but might hold it for a little bit longer.

As Tcoat said, you always retorque header nuts. This is because bolt loosening is a result of relative motion between the threads and the nut. Since the engine thermal cycles, there is always potential for the relative motion at the joint to loosen the nut because of the expansion and contraction, especially with dissimilar metals.

ALWAYS retorque. Tell your buddies to retorque. And while you're at it, tell people to stop using lock washers. They just do not work.

Chase
Engineering

[mooshu47]

Originally Posted by Tcoat

37

https://demos.starbase7.net/t3Portal..._rm_index.html

Thanks, I love me some free manuals. Bookmarked.

[Tcoat]

Originally Posted by mooshu47

Thanks, I love me some free manuals. Bookmarked.

If you go to @Ultramaroon 's sig line he has all the goodies.

[humfrz]

Originally Posted by GrimmSpeed

Whatever happened to the use of lock washers? Well, sometime around the 60s lock washers were actually found to aid in loosening joints rather than keep them tight...

Chase
Engineering

Well, I'll be dammed -

Good information.


humfrz - stuck in the 40s - still -

[Lantanafrs2]

Header leak at the head, flange interface can be fatal for your exhaust valves under track conditions.

[Spuds]

Originally Posted by Tcoat

Yep so in a couple of days torque them again. And then maybe again later. I have lost my share of nuts over the decades.

To disease, machinery, or marriage?





...ok, I'll go away now....