what part (parts) are you missing here ?
(diagram below)

'muffler-shop' "system" installed ?


BMW parts installed ?

using washers at all the bolt heads and nuts ?


_________________
1976 BMW 2002 # 2743711 (sweet dreams)
1986 BMW R65 650cc #______ 20k Mi
1964 BMW R27 250cc # 383851 17K Mi
2002 BMW 325xiTouring # PF01253 33k Mi
1984 M-BENZ W123 300DT # EA105395 188k Mi

Armond wrote:

I have changed to nyloc copper bolts but it keeps getting loose after 2-3 months which results to a exhaust leak. Will a properly positioned flexible exhaust pipe cure this problem? not sure why this keeps happening. Thanks in advance.

I am aware of nyloc nuts but am not aware of nyloc bolts. Besides, even if you are truly referring to nuts, the use of nyloc on an exhaust system is ill advised since nylon has a tendency to soften or melt at temperatures above 230 degree Fahrenheit. It is equally confusing that you mention copper in the same description, unless you are describing a copper nut with a nylon insert. In either case, seems destined for failure. Ever try lock washers?

As mentioned above, the exhaust system is not a place for Nyloc nuts. I've never had a problem with the 3 downpipe studs when using lock washers and NEW copper nuts, torqued as spec-ed.

Bob Napier

sorry i did mean nuts not bolts. CD. All the pieces you circled are present. It is a muffler shop installed system. Double nuts have also been tried.
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73 Tii. 2762730
Volvo V70 Turbo,Wagon

“We are never defeated unless we give up on God.”
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Are the studs backing out of the manifold?

Wether they are or not, try new locking copper nuts and studs. You may need a stud extractor.




Cris
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I used double nuts and loctite on mine and never lost another.
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1971 2002 - "William Grover-Williams" - Track/Weekend Car VIN 2579197
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cj wrote:

Are the studs backing out of the manifold? Wether they are or not, try new locking copper nuts and studs. You may need a stud extractor. Cris

The bolts and copper nuts are only a few months old.
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73 Tii. 2762730
Volvo V70 Turbo,Wagon

“We are never defeated unless we give up on God.”
Ronald Reagan

I've seen this a just a few times before... I think I've even answered this question here before...

Is the transmission to exhaust down pipe bracketry still there? Most of the cars I've seen that have had this problem are either missing these brackets, the bushings are bad or are simply miss adjusted; causing a vibration that loosens the collector hardware. I like to upgrade to the newer style bushings here... #18 21 1 103 237 is the OLD # all the parts programs still show the amount needed as 2 whereas the new superseded # of 18 21 1 712 091 uses 4 of them, different length bolts and fewer washers. I always use either nyloc or pinch lock nuts there too.

Another thing that causes this to happen are worn out flanges on either the down pipe and or the resonator....

Then, sometimes it's because someone miss stocked the smaller seal ring in the '02 box... I don't remember which one it is but it is slightly smaller diameter... 47mm ID for da' 02 one vs, let's say 45mm for the smaller one. It will work but comes loose and leaks, especially with worn flanges.

Been through the new hardware... yes good, now get some new copper nuts again.

I have even asked the owner to come and show me how tight they put them.... simply not tight enough

As much as I like the idea of double nutting the connection I've never had to resort to it.

HTH
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Tom Jones
BMWCCA Life 49246
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use "Stover" nuts.

They are the ones that have a slightly distorted head.

They are great on collectors and also a good solution to the CV/drive axle bolts.

Get from your local metric fastener store.

Anthony

Took the car to a local muffler shop JP Cadoux uses. Muffler guy seems to think that my urethane motor.mounts are causing more vibration and suggests that I go back to rubber. He ended up tac welding the nuts in place. Thanks so much for all your suggestions and time. I appreciate it very much.
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73 Tii. 2762730
Volvo V70 Turbo,Wagon

“We are never defeated unless we give up on God.”
Ronald Reagan

How did he tack weld a copper nut to a steel downpipe?


Cris
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They must have changed the nuts back to steel.Tried to reach you twice.
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73 Tii. 2762730
Volvo V70 Turbo,Wagon

“We are never defeated unless we give up on God.”
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Armond wrote:

Tried to reach you twice.

Your tendencies started to come back to haunt you so I had to swat you away twice!


Cris
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Armond wrote:

Muffler guy seems to think that my urethane motor.mounts are causing more vibration and suggests that I go back to rubber. He ended up tac welding the nuts in place. Thanks so much for all your suggestions and time. I appreciate it very much.

Now you tell us you've got Poly motor mounts! WHY didn't you tell us thayt in the first place??????????????????

& I was being my usual nice gut and wrote up a nice concise answer for you...................... Arg! Now I know why CJ and Sean..........
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Tom Jones
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check these out....
i got em solved all my problems
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got bolts?....well i sell them...ask me how....

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You posted a picture of studs that attach the exhaust manifold to the cylinder head. The poster was complaining of loosening fasteners where the manifold bolts to the down pipe. See CD's (Sorry he sold it!) diagram no. 2.

Ernesto wrote:

You posted a picture of studs that attach the exhaust manifold to the cylinder head. The poster was complaining of loosening fasteners where the manifold bolts to the down pipe. See CD's (Sorry he sold it!) diagram no. 2.

Um, he was complaining about the collector bolts loosening.... down pipe to center muffler flange.
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Tom Jones
BMWCCA Life 49246
A Tech@ http://www.vmwerks.com
http://www.caseymotorsports.com
http://www.ipb-autosport.com
Drive coordinator
http://www.bayarea02.com
67 1600-2 Granada
3 more 1600-2s
67 1800A
86 528e 5sp Mine 379k
86 528eA Wife's

I'm going back to the OE rubber engine mounts and hope to feel the difference. I've been using the IE Urethane engine mounts for more than a year and dont mind the added stiffness and some vibration. Hopefully, it will fix collector nut issue.
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73 Tii. 2762730
Volvo V70 Turbo,Wagon

“We are never defeated unless we give up on God.”
Ronald Reagan

So, the muffler shop guy welded the nuts to the bolts, right?

That means next time some poor schmuck mechanic is gonna quote some price for oh let's say replace some part at the back of the tranny and be stuck with having to take the extra time to cut off those welded bolts.... and then replace them... It's either gonna cost him or you more the next time something has to be done in that area. Since I do some work at Sean Casey's it may even be ME!

There are always right ways to fix things and wrong ways.

Sorry for the rant but as a professional mechanic I hate getting stuck with other peoples "fixes".... it's a waste of my time and sometimes your money.

BTW why did you omit the very important and pertinent fact that you're running poly mounts in your original question???
_________________
Tom Jones
BMWCCA Life 49246
A Tech@ http://www.vmwerks.com
http://www.caseymotorsports.com
http://www.ipb-autosport.com
Drive coordinator
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67 1600-2 Granada
3 more 1600-2s
67 1800A
86 528e 5sp Mine 379k
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tjones02 wrote:

So, the muffler shop guy welded the nuts to the bolts, right? That means next time some poor schmuck mechanic is gonna quote some price for oh let's say replace some part at the back of the tranny and be stuck with having to take the extra time to cut off those welded bolts.... and then replace them... It's either gonna cost him or you more the next time something has to be done in that area. Since I do some work at Sean Casey's it may even be ME! There are always right ways to fix things and wrong ways. Sorry for the rant but as a professional mechanic I hate getting stuck with other peoples "fixes".... it's a waste of my time and sometimes your money. BTW why did you omit the very important and pertinent fact that you're running poly mounts in your original question???

the muffler guy zapped or tacked welded the nut once and a impact gun should be able to get it out. Not mentioning the fact that I had urethane engine mounts was not a omission but rather ignorance. I didn't realize the urethane mounts had a contributing factor to the problem.

Now my question is, why even bother with urethane engine mounts? what's the purpose? TIA
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73 Tii. 2762730
Volvo V70 Turbo,Wagon

“We are never defeated unless we give up on God.”
Ronald Reagan

Armond wrote:

Now my question is, why even bother with urethane engine mounts? what's the purpose? TIA

Racing... Track junkies... to make money off those who want to be...
_________________
Tom Jones
BMWCCA Life 49246
A Tech@ http://www.vmwerks.com
http://www.caseymotorsports.com
http://www.ipb-autosport.com
Drive coordinator
http://www.bayarea02.com
67 1600-2 Granada
3 more 1600-2s
67 1800A
86 528e 5sp Mine 379k
86 528eA Wife's

tjones02 wrote:

Armond wrote: Now my question is, why even bother with urethane engine mounts? what's the purpose? TIA Racing... Track junkies...

got it. wish I was educated on that prior to purchase and installation. Watch for these mounts on the F/S section soon. time for me to search on R/R of my engine mounts. Thanks Tom
_________________
73 Tii. 2762730
Volvo V70 Turbo,Wagon

“We are never defeated unless we give up on God.”
Ronald Reagan