RawRunner

4runner owners I need your help. I have a 2001 4runner with TRD headers. There has been an ongoing leak with the headers on the last joint before it connects to the Cats. Toyota has replaced the gaskets many times and I keep having this leak. They told me to go to an exhaust specialist to get the joint welded. When I went there they told me that the area around the joint was too tight to get a welding tool in there. I am out of options at this point. Has anyone else had this problem or can anyone give me any advice at all. Any advice would be greatly appreciated.

KING

What about taking off the headers to have them weld?

rimpainter.com

Arent you under warranty? Why is Toyota passing this off on someone else? Who installed them?

shazaam

I had that gasket problem too, it was messed up a few days after the install. The shop that put mine on just tightened the ˟˟˟˟ out of it, and that did the trick. See if they can't tighten it anymore, if the gaskets are already messed up then you can't mess them up anymore right?

scharged03

Are they metal gaskets? I have a Mustang and it's well known in the Mustang community that you need metal gaskets. The paper gaskets that a lot of kits come with are worthless and should never be used.

Pitchar

paxam

I had a simular problem on my 02 taco .the bolts/nuts were coming lose .some locktight and new bolts fixed it.

Gadget

You have to be careful here. The flange that comes with the headers that you have to weld onto the front of the cat, well if you have the old system, is a soft metal and bends really easy. If you over tighten this it is bend and cause the bolt holes to pull together and the center area to bow out away from the gasket and make one big ass leak.

My TRD headers came with those crappy flat copper gaskets that were not worth a damn. If that is what you are using, get rid of it.

The stock setup works really well. It uses a crushing type gasket that will seal any oddity in the flange surface and the flanges are cut back in a way that you tighten the bolts down until the two flanges touch each other while putting the perfect amount of pressure on the gasket. TRD ignored this approach. To bad it worked really well.

Here is how I settled this on going problem on both of my trucks. I got an OEM type cat gasket and some stainless steel nuts and bolts with a bunch of flat washers. I installed the gasket and bolts, but put three flat washers between the flanges and then tightened them down.

What this did was put enough tension on the gasket to cause it to crush down and seal the connection and when the washer stack bottomed out against each side of the flange it prevented the flange from being over tightened and bowing out. It also allowed the nuts and bolts to be tightened down hard enough to keep them from rattling loose. This worked perfectly on one truck.

The other one had the flanges so warped and bowed out from prior over tightening that one gasket would not seal. I put two OEM gakets in there and 4 washers between the flanges and that did the trick just fine. They have been like that now for a couple of years and no further problems.

By the way, even TRD has dumped those flat copper gaskets for the cat connection and are now using the OEM gasket like I am.

Gadget

www.GadgetOnline.com

RawRunner

Gadget, I had the same problem with the bolts coming loose. I tightened them to death so it would stop happening and that is when I think the leak started. I’m going to try what you said about getting some stock gaskets and doubling up on them. It seems that you can’t get anything done right unless you do it yourself. Thanks Gadget and everyone else for the help.

Gadget

Remember the trick is to stack washers between the flanges. It is kind of hard to figure out how many as you want to put some pressure on the gasket to make it deform a bit and seal, but enough so the stack takes up the space and you can crank down on the nut so it will not come loose and not cause the flange center to bow away from the gasket.

I really wish TRD would have taken the time to make their flanges just like the OEM ones with a properly recessed gasket surface so it will properly load the gasket when the flange come flat against each other and not have any of these problem.

They have made a big improvement in the header to down pipe connection to solve that never ending prpblem. Maybe they will take my spacer idea and make it their own so that others won't have this problem.

Gadget

www.GadgetOnline.com

Supercharged

OK, I have a question about exhaust leak from headers. Will I be able to hear to see a leak if there is one? What are some of the common tell-tale signs? Sorry for this "ignorant" question.

ldivinag

my downey header leak is right at the flange where it bolts onto the engine.

the sound is like a fluttering noise. hold like a piece of paper to your mouth and blow on it. it will make that fluttering noise.

if still unsure, bring it to a muffler shop. they can tell exhaust type leaks rather quickly...