Go Back   Team-BHP > Under the Hood > Technical Stuff


Reply
 
Thread Tools Search this Thread
Old 17th March 2012, 17:53   #1
Senior - BHPian
 
Join Date: Nov 2007
Location: Bangalore
Posts: 2,376
Thanked: 528 Times
Default Exhaust sheared & welded back in Subaru (Chevy) Forester

I have been using the Forester (which was bought as used from a second owner) for nearly 1.5 years. From nearly 5-6 months, the engine noise was higher then normal. When I reported this issue with the service station during the service (Sundram Motors), the SA had attributed this to worn out bearings on the front wheels. I wasn't convinced with this as the noise was closely connected with the engine revs and not the vehicle speed.

Last week when I started the car, the noise became 3 times more all of a sudden. Fellow Bhpian Nandish had a look and pointed to the cracked Exhaust pipe.

I decided to get the pipe welded till the time I find a replacement (as it has to be mostly ordered). In the workshop, when the workers took out the exhaust pipe which was in 2 pieces, I realized that the previous crack was so large (all along the diameter) and pipe was holding just by an inch, which could be seen by the clean surface of metal.

Expect for this crack/shear the exhaust pipe seem to be in perfect shape, without any sign of corrosion. This made me think what could have caused the pipe to corrode in one point/section.
One of the theory I can think of is, one of the previous (2) owners must have cut it to do something (ex:remove the Cat con to make it free flow?) and not welded it back properly? Any thoughts from other Bhpians?

Last edited by GTO : 19th March 2012 at 14:14. Reason: Please use paragraph spacing; it leads to superior readability for other forum users
Guna is offline   Reply With Quote
Old 17th March 2012, 18:15   #2
BHPian
 
Join Date: Jan 2012
Location: Bangalore,Coorg
Posts: 790
Thanked: 361 Times
Default Re: Exhaust sheared and welded back in forester

It would definitely be useful if you could show us a photo of this, but from what you have said, it definitely sounds like it was cut. Do the two parts look like they are different, by which I mean is one part older than the other. That would definitely help you figure out why the crack has developed.
pganapathy is offline   Reply With Quote
Old 17th March 2012, 23:35   #3
Senior - BHPian
 
Join Date: Nov 2007
Location: Bangalore
Posts: 2,376
Thanked: 528 Times
Default Re: Exhaust sheared and welded back in forester

Quote:
Originally Posted by pganapathy View Post
It would definitely be useful if you could show us a photo of this, but from what you have said, it definitely sounds like it was cut. Do the two parts look like they are different, by which I mean is one part older than the other. That would definitely help you figure out why the crack has developed.
Unfortunately I was in a hurry to get it fixed so that I can use the car and I could not take the picture.
The two parts looked the same in terms of the age. Also the cut had taken place where the larger diameter pipe was welded to a smaller diameter (by the manufacturer).
The section of the pipe where it had broken did not have any sign of rust and it had the normal deposition from the exhaust gases (indicating the crack existed for long time and the exhaust gas was leaking through it).
If it was indeed cut, my worry is, what other tampering would have been done to the car.

Last edited by Guna : 17th March 2012 at 23:45.
Guna is offline   Reply With Quote
Old 18th March 2012, 00:32   #4
BHPian
 
BuRnT RuBbEr's Avatar
 
Join Date: May 2005
Location: DL 1
Posts: 367
Thanked: 11 Times
Default Re: Exhaust sheared and welded back in forester

Quote:
Originally Posted by Guna View Post
The two parts looked the same in terms of the age. Also the cut had taken place where the larger diameter pipe was welded to a smaller diameter (by the manufacturer).
metal fatigue? or long term failure of weld joint?
BuRnT RuBbEr is offline   Reply With Quote
Old 18th March 2012, 10:52   #5
BHPian
 
Join Date: Jan 2012
Location: Bangalore,Coorg
Posts: 790
Thanked: 361 Times
Default Re: Exhaust sheared and welded back in forester

Quote:
Originally Posted by Guna View Post
Unfortunately I was in a hurry to get it fixed so that I can use the car and I could not take the picture.
The two parts looked the same in terms of the age. Also the cut had taken place where the larger diameter pipe was welded to a smaller diameter (by the manufacturer).
The section of the pipe where it had broken did not have any sign of rust and it had the normal deposition from the exhaust gases (indicating the crack existed for long time and the exhaust gas was leaking through it).
If it was indeed cut, my worry is, what other tampering would have been done to the car.
Would it be possible to take a photo of the exhaust pipe now. Might be better than nothing.

Anyway, it sounds like possibly the original weld was not done well, which is why it was rewelded. That is the glass half full view of it.

See if you can find photos online of what the original exhaust looks like. Normally manufacturers don't weld different size pipes together. What they do is use a one piece pipe which will reduce in size. Possibly that area was cut and the previous owners FNG did the easiest thing by cutting and then welding the pipe. Does the exhaust pipe look an inch or two shorter
pganapathy is offline   Reply With Quote
Old 18th March 2012, 12:47   #6
Distinguished - BHPian
 
dhanushs's Avatar
 
Join Date: Oct 2009
Location: Bathery/BLR
Posts: 3,446
Thanked: 4,054 Times
Default Re: Exhaust sheared and welded back in forester

Weld the exhaust together, and check for any broken clamps that hold the exhaust.

Vibrations from broken clamps, could cause this. If not rectified, exhaust will still break in the same place.
dhanushs is offline   (1) Thanks Reply With Quote
Old 19th March 2012, 15:15   #7
Senior - BHPian
 
Join Date: Nov 2007
Location: Bangalore
Posts: 2,376
Thanked: 528 Times
Default Re: Exhaust sheared & welded back in Subaru (Chevy) Forester

Quote:
Originally Posted by pganapathy View Post
What they do is use a one piece pipe which will reduce in size. Possibly that area was cut and the previous owners FNG did the easiest thing by cutting and then welding the pipe. Does the exhaust pipe look an inch or two shorter
Pipe doesn't look like it has lost length.
I am posting couple of pics from net, one to show the point at which it broke and the second to show the kind of uneven diameters were welded.

Quote:
Originally Posted by dhanushs View Post
Weld the exhaust together, and check for any broken clamps that hold the exhaust.

Vibrations from broken clamps, could cause this. If not rectified, exhaust will still break in the same place.
Good point. I will check. When the workshop people inspected they did not come up with any observation but I don't want to rely on their judgement.
Attached Images
  
Guna is offline   Reply With Quote
Old 19th March 2012, 17:58   #8
BHPian
 
Join Date: Jan 2012
Location: Bangalore,Coorg
Posts: 790
Thanked: 361 Times
Default Re: Exhaust sheared & welded back in Subaru (Chevy) Forester

Quote:
Originally Posted by Guna View Post
Pipe doesn't look like it has lost length.
I am posting couple of pics from net, one to show the point at which it broke and the second to show the kind of uneven diameters were welded.

Good point. I will check. When the workshop people inspected they did not come up with any observation but I don't want to rely on their judgement.
That photo of the two size pipes being welded was exactly what I meant, just didn't express it clearly enough. Anyway, as dhanush said, check the clamps. Preferably take it to your FNG or exhaust specialist. They will pay more attention to details like this.

Additionally, check that a proper welding job has been done. If not, the issue will crop up again.
pganapathy is offline   (1) Thanks Reply With Quote
Old 19th March 2012, 18:06   #9
Senior - BHPian
 
Join Date: Nov 2007
Location: Bangalore
Posts: 2,376
Thanked: 528 Times
Default Re: Exhaust sheared & welded back in Subaru (Chevy) Forester

Quote:
Originally Posted by Guna View Post
I am posting couple of pics from net, one to show the point at which it broke and the second to show the kind of uneven diameters were welded.
Sorry I had posted the wrong picture (1st one)
Attached Images
 
Guna is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Back-to-back drive - Chevy Camaro Auto - Ford Mustang GT Auto - Chevy Camaro Man XH_Vee The International Automotive Scene 8 12th August 2010 12:36
Spotted Subaru Forester & "Chevy Forester" in Hyderabad midlifecrisis The Indian Car Scene 14 26th October 2007 12:29
Chevy nee Subaru Forester Revvmaster The Indian Car Scene 27 15th July 2005 22:29
For all you Subaru Forester Fans GTO The International Automotive Scene 10 6th March 2004 15:00


All times are GMT +5.5. The time now is 18:54.

Copyright 2000 - 2017, Team-BHP.com
Proudly powered by E2E Networks