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Re: Exhaust Manifold Stud Replacement Questions [was Re: Mystery Nut--Anyone Identify?]
"Grumpy AuContraire" <Grumpster@GrumpyvilleNOT.com> wrote
> Elle wrote: >> >> What torque should be applied to the exhaust manifold >> stud >> (91 Civic LX, 176k miles) when installing it in the >> cylinder >> head? This torque specification does not seem to appear >> in >> the service manual or my Chilton's. >> >> I see the locking nuts get 23 ft-lbs, so I suppose that's >> reasonable for the studs, too. Still, perhaps someone >> here >> has some more insight or thoughts on what is reasonable >> here. >> > > Studs should have slightly more torque than nuts as it is > desired that > the nut turn freely (when loosening) while the stud > remains in place. > this can be done by locking two nuts together when > installing the stud. > Using "lock tight" is also a possibility but may not be as > effective due > to the high heat this application must endure. > > > >> Also, ISTM I should replace all nine studs. Any good >> reason >> not to? "If it ain't broke, don't fix it," is a good >> rule, >> but on a car this old, and since broken exhaust manifold >> studs are fairly common, I think an ounce of prevention >> may >> be appropriate here. Your experience on this matter is >> welcome. >> > > Yes, I would replace all of 'em if it is not a big hassle. > > > >> I plan to double nut the studs to remove them, being >> mindful >> that they are fatigued and could very well break off in >> an >> undesirable way. >> > > That's ok. Just be patient and work the studs in both > directions to > gradually loosen 'em up. Also, a direct blow or two to > the top of the > stud itself can be beneficial. Just make sure a nut is > present to > protect the threads. Sounds good. My parts are on order locally and I think I'll work on this before my pass. side front bushings. I'm going to soak as much as I can of the applicable bolt threads in PB Blaster today. Fortunately I had the header pipe disconnected from the exhaust manifold a couple of years ago. Thanks for sharing your experience, JT. >> Again, they're 8 mm nominal diameter studs. >> >> My Civic yesterday recorded the lowest gas mileage since >> I >> started keeping careful records two years ago--36.3 mpg >> vs. >> my average of about 40 mpg (higher in late spring and >> summer). It's never been this low for this time of year. >> I >> googled and it certainly seems that the missing nut may >> be >> causing an exhaust leak and causing the engine control >> system to run rich. >> > > Ethanol mix maybe?? No. I am using the same gas stations I usually use. They haven't shifted. Last time I did get a winter mix, I didn't notice a change in fuel mileage (using odometer miles/gallons added to top off). |
Re: Exhaust Manifold Stud Replacement Questions [was Re: MysteryNut--Anyone Identify?]
Elle wrote: > > "Grumpy AuContraire" <Grumpster@GrumpyvilleNOT.com> wrote > > Elle wrote: > >> > >> What torque should be applied to the exhaust manifold > >> stud > >> (91 Civic LX, 176k miles) when installing it in the > >> cylinder > >> head? This torque specification does not seem to appear > >> in > >> the service manual or my Chilton's. > >> > >> I see the locking nuts get 23 ft-lbs, so I suppose that's > >> reasonable for the studs, too. Still, perhaps someone > >> here > >> has some more insight or thoughts on what is reasonable > >> here. > >> > > > > Studs should have slightly more torque than nuts as it is > > desired that > > the nut turn freely (when loosening) while the stud > > remains in place. > > this can be done by locking two nuts together when > > installing the stud. > > Using "lock tight" is also a possibility but may not be as > > effective due > > to the high heat this application must endure. > > > > > > > >> Also, ISTM I should replace all nine studs. Any good > >> reason > >> not to? "If it ain't broke, don't fix it," is a good > >> rule, > >> but on a car this old, and since broken exhaust manifold > >> studs are fairly common, I think an ounce of prevention > >> may > >> be appropriate here. Your experience on this matter is > >> welcome. > >> > > > > Yes, I would replace all of 'em if it is not a big hassle. > > > > > > > >> I plan to double nut the studs to remove them, being > >> mindful > >> that they are fatigued and could very well break off in > >> an > >> undesirable way. > >> > > > > That's ok. Just be patient and work the studs in both > > directions to > > gradually loosen 'em up. Also, a direct blow or two to > > the top of the > > stud itself can be beneficial. Just make sure a nut is > > present to > > protect the threads. > > Sounds good. My parts are on order locally and I think I'll > work on this before my pass. side front bushings. I'm going > to soak as much as I can of the applicable bolt threads in > PB Blaster today. Fortunately I had the header pipe > disconnected from the exhaust manifold a couple of years > ago. > > Thanks for sharing your experience, JT. > > >> Again, they're 8 mm nominal diameter studs. > >> > >> My Civic yesterday recorded the lowest gas mileage since > >> I > >> started keeping careful records two years ago--36.3 mpg > >> vs. > >> my average of about 40 mpg (higher in late spring and > >> summer). It's never been this low for this time of year. > >> I > >> googled and it certainly seems that the missing nut may > >> be > >> causing an exhaust leak and causing the engine control > >> system to run rich. > >> > > > > Ethanol mix maybe?? > > No. I am using the same gas stations I usually use. They > haven't shifted. Last time I did get a winter mix, I didn't > notice a change in fuel mileage (using odometer > miles/gallons added to top off). I think that all gasoline sold nationally now has to have an ethanol content of 10% that replaces MBTE (sp?) that was declared "dangerous" by the EPA.. There was a big fuss by the oil companies and refiners. JT |
Re: Exhaust Manifold Stud Replacement Questions [was Re: MysteryNut--Anyone Identify?]
Elle wrote: > > "Grumpy AuContraire" <Grumpster@GrumpyvilleNOT.com> wrote > > Elle wrote: > >> > >> What torque should be applied to the exhaust manifold > >> stud > >> (91 Civic LX, 176k miles) when installing it in the > >> cylinder > >> head? This torque specification does not seem to appear > >> in > >> the service manual or my Chilton's. > >> > >> I see the locking nuts get 23 ft-lbs, so I suppose that's > >> reasonable for the studs, too. Still, perhaps someone > >> here > >> has some more insight or thoughts on what is reasonable > >> here. > >> > > > > Studs should have slightly more torque than nuts as it is > > desired that > > the nut turn freely (when loosening) while the stud > > remains in place. > > this can be done by locking two nuts together when > > installing the stud. > > Using "lock tight" is also a possibility but may not be as > > effective due > > to the high heat this application must endure. > > > > > > > >> Also, ISTM I should replace all nine studs. Any good > >> reason > >> not to? "If it ain't broke, don't fix it," is a good > >> rule, > >> but on a car this old, and since broken exhaust manifold > >> studs are fairly common, I think an ounce of prevention > >> may > >> be appropriate here. Your experience on this matter is > >> welcome. > >> > > > > Yes, I would replace all of 'em if it is not a big hassle. > > > > > > > >> I plan to double nut the studs to remove them, being > >> mindful > >> that they are fatigued and could very well break off in > >> an > >> undesirable way. > >> > > > > That's ok. Just be patient and work the studs in both > > directions to > > gradually loosen 'em up. Also, a direct blow or two to > > the top of the > > stud itself can be beneficial. Just make sure a nut is > > present to > > protect the threads. > > Sounds good. My parts are on order locally and I think I'll > work on this before my pass. side front bushings. I'm going > to soak as much as I can of the applicable bolt threads in > PB Blaster today. Fortunately I had the header pipe > disconnected from the exhaust manifold a couple of years > ago. > > Thanks for sharing your experience, JT. > > >> Again, they're 8 mm nominal diameter studs. > >> > >> My Civic yesterday recorded the lowest gas mileage since > >> I > >> started keeping careful records two years ago--36.3 mpg > >> vs. > >> my average of about 40 mpg (higher in late spring and > >> summer). It's never been this low for this time of year. > >> I > >> googled and it certainly seems that the missing nut may > >> be > >> causing an exhaust leak and causing the engine control > >> system to run rich. > >> > > > > Ethanol mix maybe?? > > No. I am using the same gas stations I usually use. They > haven't shifted. Last time I did get a winter mix, I didn't > notice a change in fuel mileage (using odometer > miles/gallons added to top off). I think that all gasoline sold nationally now has to have an ethanol content of 10% that replaces MBTE (sp?) that was declared "dangerous" by the EPA.. There was a big fuss by the oil companies and refiners. JT |
Re: Exhaust Manifold Stud Replacement Questions [was Re: MysteryNut--Anyone Identify?]
Elle wrote: > > "Grumpy AuContraire" <Grumpster@GrumpyvilleNOT.com> wrote > > Elle wrote: > >> > >> What torque should be applied to the exhaust manifold > >> stud > >> (91 Civic LX, 176k miles) when installing it in the > >> cylinder > >> head? This torque specification does not seem to appear > >> in > >> the service manual or my Chilton's. > >> > >> I see the locking nuts get 23 ft-lbs, so I suppose that's > >> reasonable for the studs, too. Still, perhaps someone > >> here > >> has some more insight or thoughts on what is reasonable > >> here. > >> > > > > Studs should have slightly more torque than nuts as it is > > desired that > > the nut turn freely (when loosening) while the stud > > remains in place. > > this can be done by locking two nuts together when > > installing the stud. > > Using "lock tight" is also a possibility but may not be as > > effective due > > to the high heat this application must endure. > > > > > > > >> Also, ISTM I should replace all nine studs. Any good > >> reason > >> not to? "If it ain't broke, don't fix it," is a good > >> rule, > >> but on a car this old, and since broken exhaust manifold > >> studs are fairly common, I think an ounce of prevention > >> may > >> be appropriate here. Your experience on this matter is > >> welcome. > >> > > > > Yes, I would replace all of 'em if it is not a big hassle. > > > > > > > >> I plan to double nut the studs to remove them, being > >> mindful > >> that they are fatigued and could very well break off in > >> an > >> undesirable way. > >> > > > > That's ok. Just be patient and work the studs in both > > directions to > > gradually loosen 'em up. Also, a direct blow or two to > > the top of the > > stud itself can be beneficial. Just make sure a nut is > > present to > > protect the threads. > > Sounds good. My parts are on order locally and I think I'll > work on this before my pass. side front bushings. I'm going > to soak as much as I can of the applicable bolt threads in > PB Blaster today. Fortunately I had the header pipe > disconnected from the exhaust manifold a couple of years > ago. > > Thanks for sharing your experience, JT. > > >> Again, they're 8 mm nominal diameter studs. > >> > >> My Civic yesterday recorded the lowest gas mileage since > >> I > >> started keeping careful records two years ago--36.3 mpg > >> vs. > >> my average of about 40 mpg (higher in late spring and > >> summer). It's never been this low for this time of year. > >> I > >> googled and it certainly seems that the missing nut may > >> be > >> causing an exhaust leak and causing the engine control > >> system to run rich. > >> > > > > Ethanol mix maybe?? > > No. I am using the same gas stations I usually use. They > haven't shifted. Last time I did get a winter mix, I didn't > notice a change in fuel mileage (using odometer > miles/gallons added to top off). I think that all gasoline sold nationally now has to have an ethanol content of 10% that replaces MBTE (sp?) that was declared "dangerous" by the EPA.. There was a big fuss by the oil companies and refiners. JT |
Re: Exhaust Manifold Stud Replacement Questions [was Re: MysteryNut--Anyone Identify?]
Elle wrote:
> What torque should be applied to the exhaust manifold stud > (91 Civic LX, 176k miles) when installing it in the cylinder > head? This torque specification does not seem to appear in > the service manual or my Chilton's. AFAIK, they basically just thread all the way (half way?) in, and thats it. no torque necessary. when you attach the nut and washer, and torque *that* it tightens the stud as well, or at least causes the stud to become "elastic". |
Re: Exhaust Manifold Stud Replacement Questions [was Re: MysteryNut--Anyone Identify?]
Elle wrote:
> What torque should be applied to the exhaust manifold stud > (91 Civic LX, 176k miles) when installing it in the cylinder > head? This torque specification does not seem to appear in > the service manual or my Chilton's. AFAIK, they basically just thread all the way (half way?) in, and thats it. no torque necessary. when you attach the nut and washer, and torque *that* it tightens the stud as well, or at least causes the stud to become "elastic". |
Re: Exhaust Manifold Stud Replacement Questions [was Re: MysteryNut--Anyone Identify?]
Elle wrote:
> What torque should be applied to the exhaust manifold stud > (91 Civic LX, 176k miles) when installing it in the cylinder > head? This torque specification does not seem to appear in > the service manual or my Chilton's. AFAIK, they basically just thread all the way (half way?) in, and thats it. no torque necessary. when you attach the nut and washer, and torque *that* it tightens the stud as well, or at least causes the stud to become "elastic". |
Re: Exhaust Manifold Stud Replacement Questions [was Re: Mystery Nut--Anyone Identify?]
SoCalMike <Mikein562athotmail@hotmail.com> wrote in
news:oqCdnSJZjp0WLu7ZRVn-qw@comcast.com: > Elle wrote: >> What torque should be applied to the exhaust manifold stud >> (91 Civic LX, 176k miles) when installing it in the cylinder >> head? This torque specification does not seem to appear in >> the service manual or my Chilton's. > > AFAIK, they basically just thread all the way (half way?) in, and thats > it. no torque necessary. when you attach the nut and washer, and torque > *that* it tightens the stud as well, or at least causes the stud to > become "elastic". > I suspect you're right. Just tighten until it bottoms, then stop. I just checked several factory manuals here, and not one specifies a torque figure for the studs. -- TeGGeR® The Unofficial Honda/Acura FAQ www.tegger.com/hondafaq/ |
Re: Exhaust Manifold Stud Replacement Questions [was Re: Mystery Nut--Anyone Identify?]
SoCalMike <Mikein562athotmail@hotmail.com> wrote in
news:oqCdnSJZjp0WLu7ZRVn-qw@comcast.com: > Elle wrote: >> What torque should be applied to the exhaust manifold stud >> (91 Civic LX, 176k miles) when installing it in the cylinder >> head? This torque specification does not seem to appear in >> the service manual or my Chilton's. > > AFAIK, they basically just thread all the way (half way?) in, and thats > it. no torque necessary. when you attach the nut and washer, and torque > *that* it tightens the stud as well, or at least causes the stud to > become "elastic". > I suspect you're right. Just tighten until it bottoms, then stop. I just checked several factory manuals here, and not one specifies a torque figure for the studs. -- TeGGeR® The Unofficial Honda/Acura FAQ www.tegger.com/hondafaq/ |
Re: Exhaust Manifold Stud Replacement Questions [was Re: Mystery Nut--Anyone Identify?]
SoCalMike <Mikein562athotmail@hotmail.com> wrote in
news:oqCdnSJZjp0WLu7ZRVn-qw@comcast.com: > Elle wrote: >> What torque should be applied to the exhaust manifold stud >> (91 Civic LX, 176k miles) when installing it in the cylinder >> head? This torque specification does not seem to appear in >> the service manual or my Chilton's. > > AFAIK, they basically just thread all the way (half way?) in, and thats > it. no torque necessary. when you attach the nut and washer, and torque > *that* it tightens the stud as well, or at least causes the stud to > become "elastic". > I suspect you're right. Just tighten until it bottoms, then stop. I just checked several factory manuals here, and not one specifies a torque figure for the studs. -- TeGGeR® The Unofficial Honda/Acura FAQ www.tegger.com/hondafaq/ |
Re: Exhaust Manifold Stud Replacement Questions [was Re: Mystery Nut--Anyone Identify?]
Elle,
I have 2 4 piece sets of these (the picture doesn't show the bottom) It has 3 cams that roll out and pinch the stud for removal and installation. It sometime leaves small dimples in the stud but has never effected the operation. Check Sears, Harbor freight. Saves tones of time on studs. (i.e., threading two nuts on, having them slip, re tighten, remove stud now try to remove the nuts for the next go-around. http://www.toolsource.com/ost/produc...JT1CDLFPKJ5AD9 http://www.bugsandbuggies.com/Parts....626&SN=67&GN=9 -- Stephen W. Hansen ASE Certified Master Automobile Technician ASE Automobile Advanced Engine Performance ASE Undercar Specialist http://autorepair.about.com/cs/troub...l_obd_main.htm http://www.troublecodes.net/technical/ http://www.familycar.com/Alignment.htm |
Re: Exhaust Manifold Stud Replacement Questions [was Re: Mystery Nut--Anyone Identify?]
Elle,
I have 2 4 piece sets of these (the picture doesn't show the bottom) It has 3 cams that roll out and pinch the stud for removal and installation. It sometime leaves small dimples in the stud but has never effected the operation. Check Sears, Harbor freight. Saves tones of time on studs. (i.e., threading two nuts on, having them slip, re tighten, remove stud now try to remove the nuts for the next go-around. http://www.toolsource.com/ost/produc...JT1CDLFPKJ5AD9 http://www.bugsandbuggies.com/Parts....626&SN=67&GN=9 -- Stephen W. Hansen ASE Certified Master Automobile Technician ASE Automobile Advanced Engine Performance ASE Undercar Specialist http://autorepair.about.com/cs/troub...l_obd_main.htm http://www.troublecodes.net/technical/ http://www.familycar.com/Alignment.htm |
Re: Exhaust Manifold Stud Replacement Questions [was Re: Mystery Nut--Anyone Identify?]
Elle,
I have 2 4 piece sets of these (the picture doesn't show the bottom) It has 3 cams that roll out and pinch the stud for removal and installation. It sometime leaves small dimples in the stud but has never effected the operation. Check Sears, Harbor freight. Saves tones of time on studs. (i.e., threading two nuts on, having them slip, re tighten, remove stud now try to remove the nuts for the next go-around. http://www.toolsource.com/ost/produc...JT1CDLFPKJ5AD9 http://www.bugsandbuggies.com/Parts....626&SN=67&GN=9 -- Stephen W. Hansen ASE Certified Master Automobile Technician ASE Automobile Advanced Engine Performance ASE Undercar Specialist http://autorepair.about.com/cs/troub...l_obd_main.htm http://www.troublecodes.net/technical/ http://www.familycar.com/Alignment.htm |
Re: Exhaust Manifold Stud Replacement Questions [was Re: Mystery Nut--Anyone Identify?]
"Stephen H" <hansensw@hotmail.com> wrote in
news:RnScg.92413$Fs1.54575@bgtnsc05-news.ops.worldnet.att.net: > Elle, > I have 2 4 piece sets of these (the picture doesn't show the bottom) > It has > 3 cams that roll out and pinch the stud for removal and installation. > It sometime leaves small dimples in the stud but has never effected > the operation. Check Sears, Harbor freight. Saves tones of time on > studs. (i.e., threading two nuts on, having them slip, re tighten, > remove stud now try to remove the nuts for the next go-around. Now what do you do for studs that have broken off flush with the head or below? -- TeGGeR® The Unofficial Honda/Acura FAQ www.tegger.com/hondafaq/ |
Re: Exhaust Manifold Stud Replacement Questions [was Re: Mystery Nut--Anyone Identify?]
"Stephen H" <hansensw@hotmail.com> wrote in
news:RnScg.92413$Fs1.54575@bgtnsc05-news.ops.worldnet.att.net: > Elle, > I have 2 4 piece sets of these (the picture doesn't show the bottom) > It has > 3 cams that roll out and pinch the stud for removal and installation. > It sometime leaves small dimples in the stud but has never effected > the operation. Check Sears, Harbor freight. Saves tones of time on > studs. (i.e., threading two nuts on, having them slip, re tighten, > remove stud now try to remove the nuts for the next go-around. Now what do you do for studs that have broken off flush with the head or below? -- TeGGeR® The Unofficial Honda/Acura FAQ www.tegger.com/hondafaq/ |
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