On the Hunt for an Exhaust Leak

[bulletsforringo]

Hey All,

 

I have noticed an exhaust leak recently and I believe that it is related to where my headers connect to my exhaust system (please excuse lack of terminology, I'm still pretty new at this). While recently under my rig I took a look and it looks like this area is the culprit, and much like other "fixes" the PO did this is looking like another half hearted attempt to deal with the problem without actually fixing it.

 

Included below is a page from the FSM, I believe it is the correct page for my model, (1991 SE 4x4) but if I am wrong I welcome correction. I circled in red the area I believe is the problem, it looks like there is a gasket that goes there- is this correct? If so, what is it called so I can order it?

 

[RedPath88]

I've had troubles in the past with that gasket and the one behind it.

 

But you should also not rule out the manifold gaskets (where the exhaust bolts to the engine.) The studs that are used to secure the manifolds to the heads are known problems on Pathfinders and have needed to be replaced (often extracted after breaking) on a large number of VG30's (V6's) in these trucks... including my own.

[Slartibartfast]

My dad had the exhaust studs fixed when he bought the truck, but it still leaked at one of those flanges. He tried scabbing it with some kind of putty, and when that blew off, we decided that the cat was probably blocked up. It's run a lot better since we had the exhaust replaced (from the bottom of the headers back).

 

I'm not sure if the cat was actually clogged or if the old flanges were so corroded that the gasket couldn't hold. Either way, it doesn't have a flange there anymore.

[ahardb0dy]

I will tell you this, and this is based on experience, Get the gasket from Nissan !! The OEM gaskets are the BEST, I had used multiple aftermarket gaskets when I had my old hardbody and everyone leaked or blew out, the OEM gaskets are a multi layer metal gasket with a ring in the center that when tightened crimps down, nothing else comes close to them.

[Precise1]

Don't worry about the nomenclature, not everyone will call it the same thing. Print out what you posted and take it with you to the local store (if that is where you go) and show them.

If you call Alkorahil (see Classifieds/Services for his thread) for the OEM part, tell him it is the second gasket from the manifold and/or the first 2 bolt gasket. The 3 bolt gasket is where the first pipe bolts to the back of the manifold.

 

2 best ways to find exhaust leaks are this and you often need to do both...

Mix up some soapy water in a spray bottle. When the Pathy is cold, have a friend get in and start it the rev it a little. You should hear where it comes from so go there and look, then feel around with your hands (it's cold and wont burn you, but move fast). If it is a big leak you will feel it puff. If you can't find anything that way, spray the suspected area witht he soapy water and watch for bubbles or it simply being blown away. Sometimes a visual inspection will show black places that could be leaks as well.

 

B

[Alkorahil]

If you call Alkorahil (see Classifieds/Services for his thread) for the OEM part, tell him it is the second gasket from the manifold and/or the first 2 bolt gasket. The 3 bolt gasket is where the first pipe bolts to the back of the manifold.

 

PART NUMBER: 20692-1P100

DESCRIPTION: GASKET-EXHAUST

$7.08 (NISSAN LIST: $9.60)

[Slartibartfast]

Another way to find a leak, duct tape a vacuum cleaner to the tail pipe (engine off), turn it on, then feel/spray around for suction. That way you don't have to worry about heat and (depending on the state of your vacuum cleaner) you may be able to hear the leaks.

[ahardb0dy]

Another way to find a leak, duct tape a vacuum cleaner to the tail pipe (engine off), turn it on, then feel/spray around for suction. That way you don't have to worry about heat and (depending on the state of your vacuum cleaner) you may be able to hear the leaks.

 

 

Never heard that one before !!