PDA

View Full Version : How to install headers


Doom
April 24th, 2004, 08:46 PM
Poster by AccordNewbie

Installation
Tools:
Breaker Bar
Extensions
Vise Grip
Torque Wrench
Sockets
17mm Wrench
Header to Exhaust Manifold Gasket

Torque Specs:
Exhaust Manifold to Header bolts: 23 lb
O2 sensor: 33 lb (didn't know how to disconnect from car so I just unscrewed it from the a-pipe directly)
A-Pipe flange to header bolts: 40 lb
Hanger bolts: 28 lb
A-Pipe flange to Cat Converter: 25 lb

Well, since I had to figure the whole thing out myself, I think it would only be right to share the knowledge. It's actually a very easy installation once you do it once. You don't actually need to jack up and jack down the car like the instructions say. I'm pretty tall, 6'2, so I just leaned over and installed the parts. I installed it with my girlfriend and it was pretty easy, it took about 3 hours because one bolt took me forever to get off because of the wrong socket size, heh. You can either use air tools or if you're pretty strong you can just use a breaker bar. However, an easier way is to position the breaker bar so that you and your friend can pull on it at once. It'll seem like you cracked the bolt or something but that's the right sound. They're bolted on really tight. I personally bought gaskets from Acura for my Accord and they were about 9 dollars for both front and rear headers. The old ones look worn out but you can reuse them if you please. Well, I can go through the entire installation process so here goes. You'll need a breaker bar, an assortment of sockets (14mm and 17mm are the main ones), I had probably five different extensions (one long one and one short one for the breaker bar (3/8 inch). I also used a Vise Grip to hold the bolts when installing the new bolts on. Alright, this is the easier installation method.

1. Disconnect negative cable on battery. Jack up car on jack stands. Take off the A-pipe underneath the car. There are 3 bolts connecting each flange of the a-pipe to the headers and the catalytic converter. But first you want to unbolt the hanger that holds the a-pipe so that you can pull it out easier. Also, you'll need to start the car a little in order to take off the oxygen sensor because it contracts when heated. After everything is cooled, then go back under, with your friend holding the a-pipe, take off all of the bolts and slowly slide the a-pipe out from under the engine.
2. Take off the bolts on the headers by using extensions and a breaker bar. Fairly easy to reach if you just stretch a little. Just feel for the bolts first and then take them off. You'll have to take out the rear header from under the car. After that is done, keep all the bolts from the headers.
3. Put the Comptech headers onto the (Front one has the Carb number, Comptech had sent me two front headers when they sent me mine, it sucked) exhaust manifold and put the bolts back on. Do not tighten them yet because you'll need the flexibility later.
4. After both headers are in place (you can rebolt the headers from the top), take the new a-pipe and bolt the three new bolts onto each flange. Use some anti seize compound on the gasket that's between the a-pipe flange and the catalytic converter to hold it there in place. Also, before doing this (sorry about the order of the instructions), make sure you put anti-seize compound on the threads and only the threads of the O2 sensor, make sure you be extra careful about this because the anti-seize compound can damage the sensor. Bolt the hanger from the old a-pipe onto the car first so that you won't have to carry the a-pipe. Connect all the bolts. I found it easiest to have my gf stand on over the car and use the vise grip to hold the top bolt while I tightened it from the bottom (for the front header). For the rear header, I found it easiest to use a 17mm wrench to hold the bolt while I tightened the bolts (have your friend hold the bolt while tightening, requires some maneuvering, but not hard at all). After everything is connected, reconnect the battery cable and turn on the car. Leave the car on idle for a 3-5 minutes and then take it out for a test drive. Check for leaks but if you installed the bolts to factory specs, than you should be fine. You might smell a funny smell while driving it at first but I believe this to be the anti-seize compound burning off the gasket and maybe some of the threading on the 02 sensor. After that, have fun. If you have any more questions, I'll be around. Good luck. Sorry I don't have pics. I was too anxious to finish.

Doom
April 24th, 2004, 08:46 PM
Posted by Nzo13

Headers should come with all the parts that you need including new gaskets and seals. All you need is a wrench and ratchet set, preferrably a torque wrench. Park the car and make sure the engine and its exhaust manifold is cold not hot. And spray every existing bolt with WD-40 and let it sit for atleast 5 minutes so it is easier to unbolt them and so you don't break or snap any of the bolts. Make sure not to over tighten when installing the header causing a loose thread. This is why you should have a torque wrench. Remember that when the engine heats up, it will expand, so it will tighten and seal itself even more. If not, it's always best to use new gaskets when taking off any engine parts like this to prevent leaks, cause the lead/aluminum coating on gaskets can peel off. On the other hand, I noticed that your car is a 2000, so I would think that it will be fairly new and should be fine to re-use the existing gaskets on your car, just be careful when you peel off the parts from each other. You will know by how it looks and if you should replace it or not anyway. Then after it's all done. Start and have someone else rev the motor and listen and feel for leaks while it is cold. then go for a test drive with the windows closed and listen. That is one best way to listen for leaks is actually driving with thw windows and of course everything else off. If no signs of leaks, you are ready for business! Good luck!

PFizzle
April 25th, 2004, 01:32 AM
how did you get the cat. bolts loose cause that was the only problem i had when i wanted to install my headers....

Doom
April 25th, 2004, 10:38 AM
Try bolt loosener spray. It's very very very difficult to unscrew exhaust bolts unless you have air tools.

swears
September 17th, 2005, 02:38 PM
yeah, i couldnt get the cat bolts off. I sprayed it with penetrating oil. Is their a big difference between that and bolt loosener spray?

Also how big of an extension do you need to get the rear headers off?

Doom
September 17th, 2005, 11:00 PM
Honestly mine was done with air tools. You can PM the original posters and see what they used.

Chi
September 19th, 2005, 10:29 AM
Cat bolts let them soak in WD40 for a bit, then for that top bolt use a 12" Inch extension to break it off. The rear header Bolts I used a 24" extension which worked great. The trick is to have your car high enough so you have room to use a breaker down there I foudn it easier to use hand tools down there compared to air tools. (more room w/o hoses everywhere)

v62kaccord
September 19th, 2005, 10:32 AM
all you need is wd-40, some long extensions and GREAT strength... that's how i opened my bolts lol

metallikatz3
September 19th, 2005, 10:45 AM
yeah..i couldnt get my cat bolts off either so i just cut the nuts off then pounded the studs out and replaced them with stainless nuts, bolts, and washers. that was a lot easier than taking them off cuz mine were so rusted there wasnt any size socket that would fit the nuts anymore

kleptodathief
September 19th, 2005, 02:03 PM
nice work guys...dam i can't even do an oil change :( , do headers really help LOW end torque? a mechanic said i just need a UR crank pulley upgrade and not to waste money on headers...i don't race or anything but i just want low end back with my crappy magnaflow cat...

Doom
September 19th, 2005, 04:09 PM
He is right that pullies will help the low range.

swears
September 20th, 2005, 11:45 AM
do headers really help LOW end torque?

I'm pretty sure they help throughout the whole rpm range. Thats why I bought them.

I'll let you know when I install mine, I just need to get some WD-40, Extensions and a breaker bar. Im working on the strength part

Doom
March 19th, 2008, 03:51 PM
Another good headers install thread

http://www.v6performance.net/forums/showthread.php?t=68969

Accord_V6_400m
September 21st, 2008, 05:08 PM
Posting this info in most of the DIY headers install threads, to make the information more available when searching :)

All 3 gaskets for the Comptech headers are the same. They use 2.1" ID/2.5" OD gaskets which means you'll have to find gaskets within this range. The one that i found to work is the Honda Accord V6 pre-catback gasket, use three of these and your set.

Part # 18393-SH3-S00
http://www.hondaautomotiveparts.com/auto/jsp/mws/prddisplay.jsp?inputstate=5&catcgry1=ACCORD&catcgry2=2001&catcgry3=4DR+LXV6&catcgry4=KA4AT&catcgry5=EXHAUST+PIPE+%28V6%29
#15 in pic
http://www.hondaautomotiveparts.com/auto/jsp/mws/catimgs/13S840_B0201.gif

VietNinjaJ30A1
September 22nd, 2008, 09:35 PM
=/...I think my #23 is rattling. Any ideas how to shut it up?

Accord_V6_400m
September 22nd, 2008, 11:17 PM
=/...I think my #23 is rattling. Any ideas how to shut it up?

Emblem molding tape, check for missing bolts/nuts thats pretty much it, or you can just take it off :D

VietNinjaJ30A1
September 23rd, 2008, 04:22 AM
All the factory bolts are there and tight. You mean just double-side tape it to the underside of the floorboards?

Accord_V6_400m
September 23rd, 2008, 11:33 AM
All the factory bolts are there and tight. You mean just double-side tape it to the underside of the floorboards?

Yeah, but are you sure it couldnt be something else, try taking it off completely and see what happens.

VietNinjaJ30A1
September 23rd, 2008, 04:38 PM
I'd probably have to take the cat converter down...which is now completely welded in place in the exhaust line.

I'm like 95% positive that it's the heat shield rattling. I'll see if I can take it off by just wiggling it.

shonda1989
September 23rd, 2008, 06:23 PM
go to a shop and have them cut the shield off and weld the top one to the body that will make the rattling go away.

La0niNja7816
September 27th, 2008, 10:31 PM
Awesome write-ups. I'm hopefully tackling this down soon.