Dick R

New front exhaust pipe misalignment

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I am in the process of replacing an old poorly installed exhaust system on a recently acquired 1971 2002.   Purchased a parted out stock exhaust manifold from someone on FAQ and bought all the rest on line.  When I put in the front exhaust pipe (the one that is attached to the manifold), it was obviously misaligned by about an inch or so toward the passenger side.  As it is situated, it is impossible to attach it to the transmission mounted support and the pipe is nearly touching the side of the tunnel. 

Additional information:  While I thought I was getting all ANSA exhaust components, the front pipe was actually a IMASAF part.  Investigating further, the IMSAF part number seems to be correct (although the IMSAF website is in a European language). 

Below are a couple of pictures showing the problem. 

Can anyone shed any light on this?  Other than buying another front pipe and hoping for the best, I'm kind of stumped. 

 

 

 

 

 

 

IMG_1218.JPG

IMG_1222.JPG

Edited by Dick R
spelling

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Turn the bracket on the transmission around. It should be oriented toward the rear of the car, away from the drain plug.

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Thanks for the very quick reply. The bracket is installed correctly.  The photo makes it seem wrong.  The pipe is misaligned - nearly touching the tunnel.

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I am wondering if the down-pipe was damaged during shipment. ANSA down-pipe part # BW 0201, cross reference to BMW part # 18111104684. I have used that down-pipe before without any issue.

There is procedure on how to secure down-pipe to back of transmission. See section 13 (exhaust) on following link;

Other possibilities are: tiered engine supports can cause engine to lean more towards passenger side, therefore downpipe robbing on the transmission tunnel.

Observations from pictures – hardware connected drive-shaft to Guibo and transmission output flange to Guibo installed incorrectly. Nuts should always be against drive-shaft flange and Trans output shaft flange. See section 18 (Gearbox/Manual) on following link

 

 

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Thank you very much for your comments.  I think it is possible that the pipe could have been damaged during shipment - it was sent via UPS without any packaging - just wrapped with clear plastic and a shipping label attached.  I thought it was kinda weird, but it seems like such a substantial piece of metal that it would be difficult to damage.  Nonetheless, that could be the problem.  And for some reason, I'm thinking that an ANSA pipe would be more likely to work than the IMASAF front pipe that I received.  I haven't seen any advertising for an IMASAF branded exhaust component.  The online company that I purchased this from turned out to have a terrible Yelp rating (1.5 stars) and significant BBB problems.  I should have looked before I leaped. 

 

I thought about the engine supports possibly being the culprit.  However, the pipe's large misalignment to the transmission-mounted exhaust pipe support bracket shows that the pipe is way off regardless of any possible engine mount problems.  The mounts also seem to be in good shape and the engine doesn't seem to be listing to one side.

 

I appreciate the additional advice about the Guibo bolts.  That's how the bolts were installed as I received the car.  I was going to replace the Guibo since my center bearing was shot and I had the front drive shaft out.  I bought another Guibo, but it just didn't look very good compared the one that was in there already - which obviously wasn't original or the bolts would have been installed correctly.  While it was supposedly made in Germany, I read about fake parts and read about Guibos lasting a few thousand miles.  So I elected after much deliberation and reading lots of  postings on FAQ about new Guibos, old Guibos and Guibo bolts, to leave the current Guibo in place along with leaving the bolts incorrectly located.  From recommendation on this site, I just made sure that to tighten the bolts I rotated the bolt end behind the steel drive shaft connection and held the nut touching the Guibo stationary.  One further thing, since I had decided to not replace the old Guibo, I knew getting it back on would not be a piece of cake due to lack of the metal holding a new one together.  I used hose clamps (2) to help get the four bolts back in and that was a close call.  I think if you take a Guibo off, you're replacing it and in this case, I didn't want to do that. 

 

Thank you very much for your help.  Greatly appreciated. 

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I found a nearly three year old thread on FAQ that shows the identical problem as mine.

A couple of things stood out to me. 

1) Buckeye offered some really good advice about tightening the pipe to manifold flange after locating the pipe in the transmission mounted bracket.  I tried that and it did not work.  It was over too far and could not tighten the right side flange bolt.  I thought it was a great idea, but no luck.  Unfortunately, the original author of the posting never came back with a response to that suggestion or any kind of resolution to his problem.  He hasn't been active for a couple of years, so I assume he is not longer involved.

 

2) On his car, there was a comment made about the front pipe sticking out past the bracket more than normal.  Seems like mine is also like that.  Maybe that means that this front pipe was intended for a 5-speed or an automatic car, but got a wrong part number label at the factory.  The pipe I have is approximately 26.5 inches long straight line tip to tip.  If someone happens to have a front pipe out maybe they could measure it. 

 

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I had a similar problem a few years ago. In my case, I had swapped in a used tii manifold that I had machined at the head and downpipe mating surfaces to remove some corrosion. That must have thrown things off just enough to make the downpipe hit the tunnel. It wasn't as off as yours though. I took the car into a custom exhaust shop and they bent the downpipe into correct alignment, took about 10 minutes and $25.

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Getting the pipe bent may be the way to go.  Besides, I have nothing to lose because the way it is now won't work and I can't return it.  One potential problem might be that I'll take the pipe only, not the car with it.  I can't drive it with the exhaust straight out of the manifold for safety (fire) and sound reasons.  I'll try to find a good exhaust shop that can give it try out of the car.  Not sure that a shop (or I) would want to try to heat the pipe with a torch on the car in the close confines of the bodywork and transmission - although that's apparently how yours was bent. 

Thanks for the tip. 

 

Regarding the length of the pipe (reference my previous post), after measuring the rest of the exhaust system, it appears to me that the length of my front pipe is correct.  If it were shorter, it wouldn't reach the middle pipe. 

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Fixed.    Without torching or bending. 

 

While I was trying to determine just how much to have the front pipe bent, I noticed that the it was not only misaligned, but actually a little short.  That resulted in the middle pipe only having about ½ inch inside the muffler pipe.   But rather than taking another blind shot at ordering the front pipe online, I tried a nearby BMW repair business (in La Jolla, CA) to see if they had one in stock.   Luckily, they had only one, so I was able to do a side-by-side comparison of the two pipes, and the new one looked to my eye to be slightly different in bend and length. 

 

Turns out that it was noticeably different, much closer to where it needed to be, but still not quite there.  However, it was far enough away from the tunnel and close enough to the transmission mounted support for me to try a minor modification without torching anything. 

 

I made a simple extender from a piece of metal that I got from an Ace Hardware store.  Allowed me to move the bracket over enough to make it all fit nicely.  Seems to be well enough positioned and strongly supported.  The middle pipe and muffler are all in good alignment. 

 

The pictures show it better than I could describe it. 

IMG_1240.JPG

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IMG_1246.JPG

IMG_1249.JPG

Edited by Dick R
punctuation

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Nicely done.  I suggest replacing the tiny stock transmission rubber mount with the E21 version which is stronger.

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The stronger transmission mount sounds like good advice.  I ordered one. Thanks

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It has a slightly larger bolt, so you will need to do a little drilling.

 

Based on your beautiful countersinking skills, this will not be a problem for you : )

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On 7/13/2016 at 8:18 PM, plape said:

I had a similar problem a few years ago. In my case, I had swapped in a used tii manifold that I had machined at the head and downpipe mating surfaces to remove some corrosion. That must have thrown things off just enough to make the downpipe hit the tunnel. It wasn't as off as yours though. I took the car into a custom exhaust shop and they bent the downpipe into correct alignment, took about 10 minutes and $25.

This is the ticket.

 

I bought a new downpipe from W&N that had the exact same fitment problem.  A few minutes on a pipe mandrel will correct it.

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Dick,

Talked to you yesterday at the Encinitas car night   I have a couple of used downpipes you can try if you like

 If one will fit you can have it.  I'm 5 miles away from you

Rob

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Are you Shure that it's the pipe's fault?

Check this out-

1c5953adbb37ba7b51cc08ba67660818.jpg

A PO did this hack crazy ugly DP hanger, and it's one of the parts on the far that drives my perfectionism absolutely crazy.

So, I ordered a new hanger from WN, and it's waaaaayyy shorter than the hack job mount... Something tells me there's either an issue with the part, or there's additional longer hangers that should be able to be had.

There's no way to make the new one work without the extension mod you're showing

-J

Sent from my iPhone using Tapatalk

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