Stupid question about exhaust

Riot_Polizei

Comp Engineering Student
V
2002 Mazda Protege5
I received my headers, put them in, and found two new exhaust leaks.

One's on my RB catback exhaust system between the resonator and muffler connection.

The second's at the header and midpipe connection (donut gasket). The bolts are tightened as far as they could be on the header/midpipe connection (new bolts, springs, sleeves), as the springs don't compress anymore.

So, two questions:
  1. What gaskets do I need? I swear I put the right ones in, but I'm getting leaks
  2. Why can't I seal the header to midpipe connection over the donut gasket?

Most likely a noob question, but damn I'm tired of chasing fixes now. I did search the forum, and someone stated that the rear engine mount may cause this, but I don't know.

I just want my car to properly run agin.
 

pcb

The Diagram Dude
V
2002 mazda protege 5
[*]Why can't I seal the header to midpipe connection over the donut gasket?
[/LIST]

... I did search the forum, and someone stated that the rear engine mount may cause this, but I don't know.
The engine rotates front to back in the engine bay so that connection needs to flex.
A worn out rear engine mount will create excessive movement.

If it were me, I'd put some copper RTV silicone on the donut and reinstall it.
It might fix your other leak too.
It's good to 700 Fahrenheit.


 

pcb

The Diagram Dude
V
2002 mazda protege 5
It worked for me... I didn't want to weld it.



It's kinda cheesy and doesn't look pretty but it doesn't leak.
 

Riot_Polizei

Comp Engineering Student
V
2002 Mazda Protege5
If push comes to shove and my car still sounds like shit, I think I'll go for it. Is it removeable?

Should I put it directly on the donut gasket?

Guess I gotta go check that rear motor mount. What do I look for?

An also, the gaskets that came with the RB catback were circular without flanges. They didn't really seat very nicely. The one between my resonator and muffler flange is busted. Should I get a flanged gasket, or something else?
 

pcb

The Diagram Dude
V
2002 mazda protege 5
It's not really removable, if the surface is clean it sticks really good and has to be scraped off.

You could put it on the donut itself or the other two surfaces.
Try not to get any inside the exhaust pipe or on the inside of the donut because a piece could peel off and get blown into your muffler and get stuck in there.

I would think flanged gaskets would work better because a round one wouldn't be held in there too good.

You could put a thin layer of silicone on both sides of the gasket... That would help give it a rubbery sealed contact.
Maybe let it dry up before installing it, so it doesn't squish out when you tighten it up.

I remember reusing a head gasket on my '85 626. I just covered it with copper RTV silicone. It worked fine, I reused my head bolts too... Apparently you're not supposed to do that either.

The copper RTV silicone comes in a spray can too.
That might work better for you and sprays on nice and smooth. You could spray all your gaskets, let them dry then install them.
It makes for a neater job too.

 

Riot_Polizei

Comp Engineering Student
V
2002 Mazda Protege5
Excellent suggestions -- I'll try these out as soon as I have time to work on my car again!

Thanks a lot!
 

pcb

The Diagram Dude
V
2002 mazda protege 5
Guess I gotta go check that rear motor mount. What do I look for?
It will probably be ripped/torn inside where the rubber is.
It will look sloppy inside where it's been banging around.

PS.. The rear engine mount is a Royal PITA.
You have to break a stud off to gain access and use two foot long extensions that don't fit square on the nuts then you round them off then you're screwed.
 

Riot_Polizei

Comp Engineering Student
V
2002 Mazda Protege5
Fuck

Man, I'm getting so frustrated with this car. I'm out of money, paying off school, and this thing keeps throwing a panoply of problems at me. So many damn problems, and half of them annoying or impossible with my tools!

Christ, maybe I should've bought a corolla.
 

pcb

The Diagram Dude
V
2002 mazda protege 5
The front and rear engine mounts kinda work together to stop the engine from rolling forward and back.
The side ones stop left to right roll.

Replacing just your front engine mount can go along way towards stabilizing your engine.
Aftermarket ones are cheap and easy to install.

There was one guy here on the forums that didn't even have a rear engine mount... He broke some studs off and couldn't install the mount.
He said he couldn't even tell,.. And he had a turbo installed too.
 

pcb

The Diagram Dude
V
2002 mazda protege 5
Some guys fill their engine mounts with Window Weld to get more life out of them.
Normally you remove the mount, clean it, then fill it with the goop.
I'm pretty sure you could cleanup the rear mount and fill it with the Window Weld right on the car without removing it.



I just jammed a piece if urethane rubber in mine and called it fixed.

 

pcb

The Diagram Dude
V
2002 mazda protege 5
A lot of guys have had to replace their engine mounts,.. They get old and wear out., and a lot of them just skipped the rear mount.
The mounts are cheap on eBay but sometimes they don't fit quite right. I remember Jackie Chan got mounts and the holes didn't line up. He had to dremel the holes bigger to get them to fit.

Another sign of bad mounts is wheel hop. The engine is bouncing around and the wheels follow.

There are special mounts available (like AWR) where you can order the durometer number that you want but they are expensive.

A lot of guys that race (or drive like it) get really stiff engine mounts. It gets more power to the ground but your car starts to buzz and your teeth start to rattle.

The engine mounts are only $10-$20 each at rock auto but are over $100 each at the dealer.
 
V
2003 protege 5
Ive got 3 mounts with inserts. The sides are awr. The front is a rr and super hard. Probably like 90a. I got a rear one from them too and tried it out for like 3 months. Too many rattles for me tho so i pulled it. After a while the rear mount started to sag and i got some vibes. Then i found some liquid urethane at suspension.com in like 60a. I filled a used rear mount and 2 days later i put it in. Suprisingly it had less vibes than the sagging one. Im mentioning this for 2 reasons - one being a mount with no inserts will be the one to start failing because its still flexing. And second the window weld needs to fully cure or else it will fail and puke the uncured stuff out the sides.
Yes its true the rear mount sucks to swap but installing a mount that will last means a long time before youve gotta do it again. I chose to fill mine because i have the sport auto making a full urethane replacement too annoying for a daily driver. And the liquid urethane will do 3-4 mounts for like $40.
 
V
2003 protege 5
Yes they must be removed and the inserts fill the gaps. The awr inserts are kinda plyable so if the mount has sagged it still goes in pretty easy. The rr racing ones are stiffer and it takes some effort to get them in if the mount is older.
I chose inserts over full urethane mounts because i have an auto and its my daily. I was looking for long term reliability with some performance upgrades without making it annoying. My setup is barely noticable to my passengers and still gives firm shifts.
 

pcb

The Diagram Dude
V
2002 mazda protege 5
So Riot, you do have a few options and price ranges to choose from but being as you race, you may want to go stiffer.
Maybe remove and fill the ones you have and try to get some in the rear one ??

The window weld is thick and won't run out if it's vertical.
The liquid stuff Sleeper spoke of may work nice for the three easily accessed mounts.

Some guys were using silicone to fill their mounts but it's kinda soft.

On a related note, its illegal to fill your mounts in Australia. If you get caught you're in trouble. It's an illegal modification.
 
V
02 protege5 ES 5dr
Not all doughnut gaskets are equal. Get the variety that's tight wound wire, I wouldn't reuse an old one as they compress a fair amount.

I would look into your mounts ( maybe an issue ).

There is always this:

I have a spare AWR front mount if your wanted to try that route.
 

pcb

The Diagram Dude
V
2002 mazda protege 5
There is always this:

.
I've used that stuff too but it dries up brittle like ceramic and becomes solid.

I don't think it would work very good on the donut gasket because of the movement that would break and crumble the connection.

The high heat silicone absorbs movement and won't crumble away,... It remains flexible.
 

pcb

The Diagram Dude
V
2002 mazda protege 5
What would be nice is a flex joint instead of the leaky donut.

Our car doesn't come with it but I'm sure you could put one in there.

 
V
02 protege5 ES 5dr
What would be nice is a flex joint instead of the leaky donut.

Our car doesn't come with it but I'm sure you could put one in there.

Lol yeah but weld it. I jammed one in a lost it in traffic mid pass. Hahaha. Live 'n learn.
 

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