Exhaust leak

Posted by: WRMS

I replaced the oem header with a ebay special on my ’02. Everything went fine except, I have a slight exhaust leak.

The ticking is mainly at idle. I’ve tightened the nuts without improvement. Any suggestions?

 

Mark

Well … new oem gaskets are recommended , the ones that come with the header are usually junk . Sometimes the collapsible washers at the 3 amigos can give you trouble if you don’t tighten them evenly . Do you know where the leak is ?

 These are the ones you don’t want to use …

How do I figure out where the leak is?

Mark

Posted by: WRMS

How do I figure out where the leak is?

 

Mark

I’ll just quote “cap”  and I’ll add that I had to use soapy water in a spray bottle and look for bubbles 

Yep. Im actually helping hello  do his tomorrow because of these leaky gaskets.  Going to replace with OEM. 

I was having a similar problem with the Che flat gasket for my 2zz header to the Chinese down pipe.  It uses the same material and eventually the gasket cant handle the heat and blows out in middle separating the gasket in half.  

 I had to make my own by using what is known as a carbon felt gasket. Not applicable in this case but this is one of the things that sucks with the cheap Chinese header but completely fixable.  

Posted by: Dev

Yep. Im actually helping hello  do his tomorrow because of these leaky gaskets.  Going to replace with OEM. 

I was having a similar problem with the Che flat gasket for my 2zz header to the Chinese down pipe.  It uses the same material and eventually the gasket cant handle the heat and blows out in middle separating the gasket in half.  

 I had to make my own by using what is known as a carbon felt gasket. Not applicable in this case but this is one of the things that sucks with the cheap Chinese header but completely fixable.  

 

Dev is a lifesaver!

Posted by: phats

The idea of laying under a cold car is much more attractive then laying under a hot running car 😉 .

Mark

I’ll just quote “cap”  and I’ll add that I had to use soapy water in a spray bottle and look for bubbles 

My Favorite Trick to finding Exhaust Leaks, is to use a ‘Shop Vac’ hooked up to ‘Blow’. Take the hose from the Shop Vac, and Tape it to the COLD outlet of the Exhaust Pipe. When you turn on the Shop Vac ( Now a Leaf Blower ) it will pressurize the Exhaust System. You can now , at your leisure, crawl around under, over or inside of your car, Feeling for exhaust leaks, and not get burned. I have found MANY exhaust leaks that way.. 
Some Members have chastised me for telling people to blow krap into the engine by way of the Exhaust Pipe. Granted one Exhaust Valve will be open while you are doing this, but the corresponding intake valve will not likely be open. And if it is, it’s not by much ( Valve Overlap ).. All I can say is I’ve been doing it for a long time, and not had any problems ( That I Know of ) yet..

 

Mark, SW-Indy bought a replacement header for his Spyder, and after laying a straight edge on the flange, discovered it was warped! He had it machined so it was flat. Maybe…

My exhaust leak wasn’t there when we finished the header swap. It appeared a couple of hundred miles later and part of the problem was a lost nut and a lost stud  (That right there is an example of some pretty impressive wrench turning dontchathink. 😑) . Today, through magical thinking and clean living, I fixed it. I took some soap and water and spayed the obvious possibilities. I couldn’t  see any bubbles, but the ticking went away! Fixed!! 😉 So, my contribution fro future searchers is to just spray it with soap and water….oh yeah, you need magic and clean living as well.

Mark

Full disclosure about my conversion to a header.

I specifically chose one that used very thick (3/8” or 10mm) metal stock for the manifold mating surface.   I expected it to be warped from the welding process which I verified, and spent a few extra $ getting it milled/surfaced.  Stock manifolds and many of the aftermarket headers use thinner steel for the mating surface.  Maybe 1/8” thick and the perimeter of the plate is rolled out from the engine head,( for stiffness maybe?).

I did replace the manifold studs with longer studs found at my local, average auto parts store 

Evidently, magic and good living have a short life span as a fix for exhaust leaks.

i guess I’ll try the leaf blower next!

Mark 

Here is a pic of the header I chose for the thick, machinable, mating surface.  Around $100 on the ebay, probably Asian, had the name of MANZO.  I does best with longer manifold studs than the OEM.

These new crop of swap headers seem to be leaky. The previous ones from ten years ago were better at the head but the new ones are better at the downpipe end.  

There is another way to solve this issue and that is to make your own gasket out of the Remflex material or Percy carbon X and use high temp thread locker.  

The problem I have with my 2ZZ is the downpipe side as it uses a flat gasket with the cheap Chinese downpipe that keeps blowing out and the vibrations are making the screw back out.  

So far the Percy gasket is holding with the thread locker but just incase I ordered a blank Remflex graphite gasket to try out if I get another blow out.  The interesting thing about this gasket is its suppose to crush to 50% and will seal any untrue matting.  The trick to these gaskets is to not over tighten them and to use less than 20ftlb or torque so it has enough spring in them so no retorting is necessary and the bolts don’t walk. 

A lot of times blow outs are the result of the nuts loosening up.  

All of those headers are really thin steel and if they aren’t leaking now, they will likely crack later.  You will get the same performance and even a nicer sound, IMHO, by gutting precats in a stock header.  The installation is the same, you would just add in a step to remove the precat material.

I still still have the OEM header. In the original operation, I couldn’t get a CO2 sensor out, so I put a replacement header on. Since then I got the CO2 sensor out but stripped out the bung.

I can’t find anyone to repair this as yet. The idea was to gut it and keep it for when the ebay header fails and return to stock.

Mark