Exhaust Leak!

Anonymous · April 5, 2004, 15:32

Hi!
I have been considering gutting my Pre-cats but when I checked out the procedure I noticed my Top Secret modded exhuast has removed the main cat! s:shock: :shock: s:shock:
I'll be keeping my precats in the hopes that it will help me pass my emissions with a tank of BP cleaner fuel and prehaps some additives s:roll: :roll: s:roll:
I will just have to convince myself it is a rarer problem than previously thought ~(only about 5% of american spyderchat members have had any problems with their 2000-2002 model MR2's)

The worrying thing though is i have noticed that the exhaust seems to be leeking at the point where the pre-muffler pipe connects to the muffler pipe, there is soot on nearby pipes and a more obvious gap at the joint. I dont think it can be tightened any more than already is.

Is there anything than can be used to fill this gap without removing the exhaust or similar? Like a filler?
Would rust free paint work? s:? :? s:?

Advice appreciated s:D

s:D

markiii · April 5, 2004, 15:41

there should be a crush gasket that sits there, and teh pipes should be connected with spring loaded bolts to keep it under tension.

you probably hgave one or teh oteh rmissing.

as for MOT, I had mine checked with just teh pre-cats and it passed.

GSB · April 5, 2004, 15:52

I think its more a sort of reinforced graphite "doughnut", rather than a traditional crush type gasket, it allows a little movement between the cat section and the silencer. See part 9 below:

The 2 flanges at this point have a gap between them by design, as the stock bolts have an unthreaded section that wont let you tighten them up to much, the springs then provide enough pressure on the joint surfaces to enable a seal, while the rounded surfaces of the gasket allow some angular flex.

markiii · April 5, 2004, 16:17

true, however having seen the state of mine that came off when teh H&S was done, it was certainly crushed beyond re-use

Anonymous · April 5, 2004, 19:01

Thats whats missing then.. I have no springs!
I can understand why it wont tighten any more, but couldnt think how it would seal properly otherwise.

I think i will try to fill in the gap somehow, the nuts are pretty rusted and look REAL tight.

Thanky for the input guys s:D

s:D

Chris · April 6, 2004, 13:32

don't ya just hate tight nuts? s:wink: :wink: s:wink: s:roll: :roll: s:roll:

another case for captain wd40 me thinks...

Anonymous · April 6, 2004, 23:41

sorry for going off topic, but how much power do you rlease if you get rid of the main cat?

Tem · April 7, 2004, 08:20

Quote from: "Tomr2"sorry for going off topic, but how much power do you rlease if you get rid of the main cat?

m http://www.ppeengineering.com/mr2header.htm m

Stock 121hp, with header 126hp, with high-flow cat 129hp, without any cat 132hp.

So in that case losing the cat gave 6hp...might be a bit different with stock/another header, but should be in that area..

mph · April 7, 2004, 08:40

Quote from: "Tomr2"sorry for going off topic, but how much power do you rlease if you get rid of the main cat?

removing CAT and replacing stock exhaust with custom? 44bhp s8)

s8) ..but turbos are a bit more picky about gas flow s:wink: :wink: s:wink: Sorry!

Anonymous · April 7, 2004, 10:34

I found some really cool filler at Halfords, it just slipped into my hand and seems perfect for the job s:D

s:D
A kind of putty that when moulded turns as hard a steel (apparently) and operates at tempratures of 0 - 160 degrees C (or thereabouts.. possibly 0- 120).

THought i'd let anyone with a similar problem know, there are many varieties but only some suitable for the temperature and resiliant to vibration s8)

s8)

aaronjb · April 7, 2004, 13:18

Yikes - if you mean the stuff I think you do..

You do realise that will either a) form a wedge and fall out (either into your exhaust! or onto the road. Hope for the latter!) or b) weld your exhaust together so you can never get it off.. right?

GSB · April 7, 2004, 13:27

Quote from: "vibratingsky"I found some really cool filler at Halfords, it just slipped into my hand and seems perfect for the job s:D s:D
A kind of putty that when moulded turns as hard a steel (apparently) and operates at tempratures of 0 - 160 degrees C (or thereabouts.. possibly 0- 120).

THought i'd let anyone with a similar problem know, there are many varieties but only some suitable for the temperature and resiliant to vibration s8) s8)

No,no,no... Fix the fault, NOT the symptom.

That joint filler will only make a mess, and fall out when the system flex's. You are adding more work to when you fianlly fix it properly and have to clean that crap off.

Buy a new gasket, and get yourself a couple of springs, pull the joint apart, clean the joint faces with emery paper, insert new gasket, and remake the joint, ensuring that its not so tight it crushes the gasket...

Anonymous · April 14, 2004, 12:58

Now here is where some of you will get smug s:oops: :oops: s:oops:
The stuff from Halfords is operational from -40C to + 180C however it started to burn on a high speed cruse and stank the car out (via air conditioning)

It just burned and flaked off! s:shock: :shock: s:shock:
I need a new crush gasket but cant find a dealership that does one for a 'Top Secret' performance exhaust s8)

s8)
the garage guy thinks the mix of exhaust gasses and air will screw up the O2 sensors and affect performance s:(

s:(

Anyone know where i can get one...
I hope my experience help someone out s:roll: :roll: s:roll:

GSB · April 14, 2004, 13:08

Just to get this straight, asn so we know we're talking about the same joint here...

Are you refering to the joint that is right under the car at the bottom of the exhaust manifold? (2 pipes side by side - 3 bolts - big flexy tubes)

Or, the joint where the standard cat unit connects to the silencer. (close to the rear left light cluster, 1 pipe 2 bolts with springs)

If its the former then the gaskets are available from MR T. part number is above.

Anonymous · April 14, 2004, 13:36

I dont have a standard cat anymore s:? :? s:?
But your right MrT might be able to help out, since the manifold running from the precat will likely be the same size.

Thanks! s:wink: :wink: s:wink:

GSB · April 14, 2004, 13:45

Quote from: "vibratingsky"I dont have a standard cat anymore s:? :? s:?
But your right MrT might be able to help out, since the manifold running from the precat will likely be the same size.

They'll be exactly the same size, as they'll be the standard Toyota Gaskets. Should cost no more than about £20, and will work an awful lot better than Halford's exhaust gunge!

Anonymous · April 14, 2004, 15:53

Right went ot see Mr T. He says its not really a problem, but if it was the stock gasket wouldn't fit anyway.
I dont know the make of my exhaust, i think it is Top Secret but cant say for sure. So i have tried the gunk again, this time tempted by Holts FIREGUM, 100% CO2 proof and resistant to 1000'C, heat from the exhaust hardens it to a gastight joint. s8)

s8)

If this doesnt work im looking at alot of expense for a minor problem s:(

s:(

I'll keep you posted!

Anonymous · April 14, 2004, 17:46

So far so good, the FIREGUM swelled up at first making the neat seal look more like a doughnut around the gasket s:shock: :shock: s:shock: This has become hard now though, only where an air bubble escaped during the setting process needs to be resealed.

There is a definate difference in exhaust note! She'll be back to her old self i hope s:wink: :wink: s:wink:

GSB · April 18, 2004, 10:14

Quote from: "vibratingsky"Right went ot see Mr T. He says its not really a problem, but if it was the stock gasket wouldn't fit anyway.

Of course he'd know that for sure, having stripped the joint apart. s:roll: :roll: s:roll:

My guess is that if only one side of the joint is different to stock, and the other is a stock Toyota manifold, then the stock gaskets will be right for the job. In fact I'd put money on it. £5.22 in fact, because thats what a pair of these gaskets cost from Mr T.

Anonymous · April 18, 2004, 11:32

Having a few brains myself i thought the same thing. The mech thought the entire manifold had been changed, but at least i know what to do the next time i have cause to remove my exhaust...
and with a $500 exhaust i isnt't going to be replaced in a hurry s:shock: :shock: s:shock:

Anonymous · April 28, 2004, 17:35

The seal didn't hold for more than a couple of weeks s:roll: :roll: s:roll:
Looks like i will be hunting for a gasket especially for my exhaust.

If anyone knows where they can get a Top Secret exhaust from I would appreciate the link, hopefully there i can find my golden gasket s:lol: :lol: s:lol:

Moral of the story: Fix the problem not the symptom *sigh*

GSB · April 28, 2004, 18:03

I'll just say it one more time...

Buy a couple of Toyota Gaskets at the grand price of £5.22, as its 99% likley that when you pull the joint apart, they'll be the gaskets you need...

If not, its a fairly simple measure to take some measurements and either have one made, or obtain the marerial required to make one yourself. If you need help with this, I have a load of contacts in the gasket world, who will be able to advise you on the best material to use....

Anonymous · April 28, 2004, 18:36

Thanks, i will go to Toyota ASAP and get some. Your right s:wink: :wink: s:wink: