TeGGeR ( Exhaust Question)

TeGGeR

Exhaust question if you have the time to answer as I appreciate your
opinion's.

I want to change the exhaust header pipe flange gasket on a 01 CR-V .

The flange is on the exhaust header pipe , to the rear of the oxygen sensor
where the cat/converter, bolts to the header pipe. Does not appear to be a
very big job for one person, with the car on jack stands, one O ring hanger
on the exhaust pipe after the cat/converter and one hanger-on the muffler,
not sure if I can remove bolts and old gasket with out dropping the whole
system., Might try and shove it to the rear enough to R&R the gasket.

The flange bolts appear to have springs on them, assuming I can get the
bolts loose with out breaking them, (plenty of penetrating oil over night)
I have a torch if I have to cut them off, and install a new gasket I am not
sure how tight to torque the flange bolts. I think that this gasket is what
is refereed to as a donut type. Not sure over tightening the bolts will
compress the new gasket and damage it.

Any ideas?

Thanks
Tom

 

I'm not familiar with this specific setup, but you may well be able to flex
it enough to get the gasket out. You may have to undo a bracket or two
downstream, I don't know.

The chance of you being able to undo those bolts is next to nothing. You'll
probably just snap them in two. Go to the dealer and get a new bolt set
(you'll probably get new springs as well). Don't substitute aftermarket
bolts. They often have the wrong step profile.

If yours are anything like mine, you can either just twist until they
break, or hacksaw them in half in the middle of the spring. The other end
of the bolt is held by a nut that will fall off once you break/cut the
bolt. Watch the spring! It's under tension!

Torque on the flange bolts is on the order of 16 ft lbs. Tighten evenly
little by little, alternating side to side.

 

The reason I want to R/R the flange gasket is I suspect it to be leaking and
causeing a what sounds like a rattle in the exhaust system, when the rpms
are at 2000-2300. I have read about other owners experienceing the this
problem.

Tom

 

----------------------------

I had mine apart a month ago. Leave the exhaust system in place while
working on the 'donut' gasket. The springs aren't terribly strong, and
the bolts that go through the springs are only held on by the small
nuts. There are no threads on either of the flanges. I used a nut buster
to mangle the nuts and Vise Grips to get them loose. Don't try to turn
the bolts since the nuts are the key to the job. I got replacements for
the nuts at Canadian Tire.

'Curly'

 

More likely a heat-shield's loose. You're just the right age for that.

 

Guess I overstated the corrosion issue. How much rust can an '01 have on
its exhaust anyway?

You're probably more right than I am here, but I still think our friend has
a loose heat shield, not anything wrong with his gasket. How often do those
go bad, anyway? I'VE never seen one.

 

----------------------------------------------

Yeah, he was asking HOW to do it. I didn't feel (today) that it was my
duty to ask WHY. I had mine apart because of a plugged CAT. The
'donut' gasket looked like it would go 10 more years . . . .


'Curly'

 

Curly Q.

I called the dealer yesterday to ask about replacement bolts and nuts, to
fasten the cat to the header and they said there are no bolts, there were
only the studs in the converter, mine sure look like bolts. He said if you
break them you had to buy a new converter.

Assumeing I don't have a loose heat shield, which I hope thats all it is,
and the fastners that hold the converter to the header pipe come off with
out alot of work how much time am I looking at replacing the donut?

Thanks

Tom

 

OH yeah the donut cost $28.10. bolts $9 ea , ouch!

Tom

 

-------------------------------

Dealer is a goof. He's describing the special splined bolts on the BACK
side of the CAT, which are almost identical to wheel nut studs. They are
replaceable, but almost welded to the CAT with rust, but it's a great
LINE, if you can sell a guy a new $800 CAT just because the bolts are
rusted.
-----------------------------

---------------------------------

Heat shield is most likely rattler, since the donut is non-metalic, and
under spring pressure. Using 10 mm socket on a medium extension, remove
bottom half of shield, beat it to pulp with hammer. re-install. Rattle
fixed.

If you feel you have to do the donut, look at the diagram at
www.slhondaparts.com for a (poor) view of your parts. Just bust the nuts
with a cheap nut splitter and crank them off with Vise Grips, take one
of the very special spring-retaining bolts to store and get 3 new nuts
(I always manage to drop one under something immovable along the way).
Mine has 140,000 Km and donut didn't look 'worn'.

'Curly'

 

Curly Q.

I will be sure to check out that heat shield this week end as the noise
(rattle ) seem to increase daily, I only have 33 k on my CR-V and also find
it hard to believe that the donut is in need of replacement. Thanks to you
and TeGGer for your assistance.

Tom

 

Crawled under the car today looked at the heat shields, nothing loose there,
exhaust connections looked OK also no evidence of a leak.I would think I
would see a carbon substance it there were a leak!

Maybe its a vibration issue at the 2300rpm range, thats making the noise, or
a baffle in the muffler, but I am not going to bother with the noise it
makes, it only does it when in OverDrive gear on a flat surface,with a
slight load on the engine, no noise in the lower gears. that being said I'll
have to get used to it, and live with it.

Tom

 

Integras have a double-walled "A" pipe from the exhaust manifold to the
cat,and a weld on the inner ppipe breaks and you get a buzz at ~3300 rpm.
I'm not sure if your CR-V has such a dbl.walled A pipe,though.
I've seen a procedure on the web where you cut two slots 1/4" apart with a
hacksaw through only the outer pipe,dimple in the inner piece to contact
the inner pipe,and braze the opening shut.I have not tried this myself yet.
My GSR has the buzz/rattle,the heat shields are removed except for the
manifold shield,and that has a hose clamp snugged down on it.

 

I wonder if the Honda people would know if the pipe is double walled, or if
there is a service bulletin on this?

Funny the buzz is only at 2300 rpm and in overdrive gear with the slight
load on the engine.What pisses me off is this is about the RPM that I drive
in most of the time

I supose people with dual exhaust on there V8's get used to the noise, I can
get used to the buzz,rattle,shutter,or what ever it is!

Tom