w123 300TD exhaust down pipe question - PeachParts Mercedes-Benz Forum

Chad300tdt · #1 05-26-2010, 09:50 AM

I have:

1 1234905615 Muffler/Resonator; Center
1 1234905715AN Muffler/Resonator; Rear

The header/down pipe is rusty but has no holes. A new one costs $170. I'm also concerned with stripping out the bolts that hold it it to the upper flex pipe that connects to the turbo.

I was considering wrapping the down pipe (minus the flex pipe area) with that muffler tape that cures and fuses when the engine heats up.

Does this sound like a bad idea or a good way to prolong the down pipe and save $170? I think I'd spend about $20 for the muffler tape.

vstech · #2 05-26-2010, 12:13 PM

I wrapped the short tiny section of flex on my 87TD between the #2 and #3 cylinders on the exhaust manifold, it's holding well with a HUGE crack. I used the permatex red exhaust wrap. I think it would do a very good job of sealing off the section. if it were me, I'd totally clean and rust remove the outer section, then treat it with the high temp exhaust paint/epoxy stuff, and follow the instructions to the letter, with it. it's supposed to be cured in an oven for 4 hours or something, then cooled slowly... IIRC you have a kiln. I don't know if it has a low temp setting, but it might be worth looking at.
that tape from permatex will not cover much area, and the down pipe is very large... you'd need like 6 or more packs of the wide tape to cover with the recommended 2-3 layers of the stuff...$$$

aaa · #3 05-26-2010, 11:00 PM

Take the pipe to an exhaust shop. Oddly enough I got my pipe from peachparts for 90... that was last year though.

JB3 · #4 05-27-2010, 09:44 AM

a decent exhaust shop should be able to easily fabricate the area in question for less money, especially if your bring it to them if the bolts turn. Do you have access to a torch?

I had a complete custom 2.5 inch system from the down pipe back put in once for 200 bucks.

t walgamuth · #5 05-27-2010, 10:17 AM

If it has no holes why monkey around with it? They last for decades.

Graplr · #6 05-27-2010, 10:24 AM

Quote:

Originally Posted by dropnosky

a decent exhaust shop should be able to easily fabricate the area in question for less money, especially if your bring it to them if the bolts turn. Do you have access to a torch?

I had a complete custom 2.5 inch system from the down pipe back put in once for 200 bucks.

When my downpipe tore I called an exhaust shop to ask them about fixing the flex pipe. They gave me a quote of around $250!

Like Chad stated, a whole new part was only a hundred something.

I ended up buying a section of flex pipe and welding it in myself for a temporary fix. Cost me like $10-20 for the pipe. I haven't checked to see how it is holding up lately. This was about a year ago.

I'm with Tom, if it is not leaking, leave it as is. You can always replaced it down the road if it starts leaking. Not sure how it is on a wagon but on my SD it is pretty easy to get on and off. I would imagine it would be similar on a wagon. Maybe a 1/2 hour job tops.

Chad300tdt · #7 05-27-2010, 10:30 AM

The down pipe seems OK and the flex pipe portions are fine. I was just concerned since the whole pipe is coated with surface rust and if I tap it, flakes come off.

I was figuring that the pipe must be getting thinner and it's only a matter of time before a hole comes through, especially near that bracket that resides at the bottom of the pipe a few inches before it connects to the center resonator pipe.

Maybe I'll just wrap that area up to the flex portion.

OldPokey · #8 05-27-2010, 12:03 PM

Quote:

Originally Posted by Chad300tdt

I'm also concerned with stripping out the bolts that hold it it to the upper flex pipe that connects to the turbo.

PO's mechanic did that when swapping motors. I got that flange out (along with the manifolds and turbo) and got the stripped stud out. I've got to find another stud before I put it back together.

t walgamuth · #9 05-27-2010, 01:37 PM

Quote:

Originally Posted by Chad300tdt

The down pipe seems OK and the flex pipe portions are fine. I was just concerned since the whole pipe is coated with surface rust and if I tap it, flakes come off.

I was figuring that the pipe must be getting thinner and it's only a matter of time before a hole comes through, especially near that bracket that resides at the bottom of the pipe a few inches before it connects to the center resonator pipe.

Maybe I'll just wrap that area up to the flex portion.

I would fear that wrapping it would lessen its life.