Cheap way to fix disastrous exhaust on 240D? - PeachParts Mercedes-Benz Forum

BodhiBenz1987 · #1 09-23-2010, 10:42 PM

The exhaust is pretty much hanging by threads, if you will, on my 240D. The car has also started idling violently, which I'm assuming is a separate problem, but the exhaust is so loud that I can barely tell what sounds the engine is making at idle and can't hear it at all when revving. It also stinks to high heaven and probably isn't very healthy not to mention good for mother nature. Basically, if I want to continue driving the car, I need to fix the exhaust. I don't plan on sinking a lot of money into this car in the near future ... it is rusted, has almost 366K and, as mentioned, is not running well (although it was a month ago

). I'm more focused on the 87, which with some work can be a really, really nice car. But, I like driving the 240D, especially since the 87 is in drydock right now, and would like to keep driving it until it just craps out. So, what I'm looking for is this: What's the cheapest way to go about fixing (or mostly fixing) the exhaust? It is not patchable ... it's already been patched, and the pipe in front of the patch is half disintegrated. It's rusted all the way up to the header and back to the muffler, and I think it's missing a hanger at the middle of the car. Should I take it to a Midas and see what they say? I don't mind throwing a little money at it, just don't want to spend $800, you know? Is it an option to take a decent looking exhaust off a car in a junkyard and bolt it on?
In short: The car is a beater, but it's a much-loved beater that I'd like to keep plugging along. But my ears (and nose) are starting to hurt.

pawoSD · #2 09-23-2010, 10:46 PM

Straight pipe it.

Fulcrum525 · #3 09-23-2010, 10:51 PM

Quote:

Originally Posted by pawoSD

Straight pipe it.

X2

or find a junkyard exhaust

jonbobshinigin · #4 09-23-2010, 10:53 PM

If you can weld or know someone, a straightpipe can be a very cheap option actually. Maybe put a muffler on the rear part at some point. Apparently the necessary parts can be found at a basic hardware store!

BodhiBenz1987 · #5 09-23-2010, 10:53 PM

Quote:

Originally Posted by pawoSD

Straight pipe it.

I think that's what I have. It goes straight out the header.

I could run pipes up over the ceiling, like stacks. But I think I'm going to go the the boring old traditional cat, muffler, pipe-out-the-back thing.

BodhiBenz1987 · #6 09-23-2010, 10:55 PM

Quote:

Originally Posted by Fulcrum525

X2

or find a junkyard exhaust

I may check junkyard. I mean, even if it's not perfect, its' going to be better than what I have. I can't weld, and don't know anyone off the top of my head. I'll ask my brother in law, though, because I think he has one friend who has fabricated exhaust before.

BodhiBenz1987 · #7 09-23-2010, 10:56 PM

Quote:

Originally Posted by jonbobshinigin

If you can weld or know someone, a straightpipe can be a very cheap option actually. Maybe put a muffler on the rear part at some point. Apparently the necessary parts can be found at a basic hardware store!

Won't a straightpipe still be pretty loud? And dirty?

Fulcrum525 · #8 09-23-2010, 10:58 PM

Quote:

Originally Posted by BodhiBenz1987

Won't a straightpipe still be pretty loud? And dirty?

I've been running without a muffler for a few years now and i've never really noticed an increase in noise

(That was true before the flex pipe broke....hurray for turbo whistles!)

funola · #9 09-23-2010, 11:10 PM

Your 240D has no turbo, which acts like a very good muffler. Straightpipie will be loud.

DeliveryValve · #10 09-23-2010, 11:19 PM

Quote:

Originally Posted by BodhiBenz1987

I may check junkyard. I mean, even if it's not perfect, its' going to be better than what I have. I can't weld, and don't know anyone off the top of my head. I'll ask my brother in law, though, because I think he has one friend who has fabricated exhaust before.

It's a shame many pristine exhaust systems (of course with the rust free cars) wind up in my local yards. Many just laying on the ground under the car just waiting to be picked, but most likely never will. I'd send you one, but shipping would be astronomical you'd be better off buying new.

With that said and if your willing and want to experiment go to Craigslist or used tool shop and find a good used cheap Lincoln or Miller Mig welder setup, chop saw, go to ACE hardware get 2 1/2 inch piping and have fun fabricating your own exhaust. Oh by the way, there is no cat, just resonator, and then a muffler.

Billybob · #11 09-23-2010, 11:28 PM

Once you figure out exactly what pieces are un-repairable check eBay as there is sometimes NOS stuff that can be had pretty inexpensively. As far as effecting repair in lieu of replacement parts, one strategy which is worth considering is flexible stainless exhaust pipe and stainless flat band clamps. You can cut an un-repairable section out and with two band clamps scab in a section of flex pipe. You don't have to worry about fitting and aligning things because you can just bend things around a little.

Most MB exhaust is 50 mm ID just less than 2'' so 2" flex and band clamps get it done. Auto Zone sells 18" sections of flex pipe in numerous sizes in both stainless and plain steel, band clamps are least expensive from some place like JEGS, their about $6 a piece there. JC Whitney used to sell 304 stainless that was about $8 a foot when you bought a 10 foot section. I've got some pieces that I've used and reused numerous times on various exhausts over 15 years! If I junk a vehicle that used it I would cut it off before consigning the hulk to the bone yard.

The bone yard is a viable alternative also, if they'll sell exhaust parts. I would do a close inspection and surgically remove the section I needed plus a couple inches on the other side of the joint, that way you can disassemble the joint on the bench to avoid damaging it. If you find a good complete exhaust try to get it off in one piece and install it on your car the same way rather than breaking it into pieces and parts. When you go to the bone yard just bring that throw rug in the hallway and the clothes line out back. When you get the entire exhaust off wrap the rug around it to "protect it" and tie it onto the roof for the ride home like a hunter returning to the home hearth with his kill!

pawoSD · #12 09-23-2010, 11:29 PM

Quote:

Originally Posted by BodhiBenz1987

Won't a straightpipe still be pretty loud? And dirty?

Dirty? The stock exhaust has no filtering of any sort, it just muffles the sound of the soot blast.

If I hit mine hard enough I can leave soot on a car behind me if they are tailgating. Which is perfect.

BodhiBenz1987 · #13 09-23-2010, 11:31 PM

Quote:

Originally Posted by DeliveryValve

It's a shame many pristine exhaust systems (of course with the rust free cars) wind up in my local yards. Many just laying on the ground under the car just waiting to be picked, but most likely never will. I'd send you one, but shipping would be astronomical you'd be better off buying new.

With that said and if your willing and want to experiment go to Craigslist or used tool shop and find a good used cheap Lincoln or Miller Mig welder setup, chop saw, go to ACE hardware get 2 1/2 inch piping and have fun fabricating your own exhaust. Oh by the way, there is no cat, just resonator, and then a muffler.

Maybe I'll have a look at one of the nearish pick-n-pulls ... I've been meaning to go for a while anyway and could grab some other stuff while there. I'm not really sure if I can fit an exhaust in my Jeep though ... may have to wait until I can use my dad's van.

I thought it had a cat ... oops. What does purpose does the resonater serve?
And I would love to learn how to weld. I've been saying for three years I'm going to do it, and I never do. I guess I'm afraid and/or don't know where to start, even though I've got a couple simple DIY welding guides I've read. I've kind of got my focus now on replacing the subframe on my 300D (another project I'm kind of afraid to take on) but maybe if I can get that done I'll have the confidence to try another new thing in welding.

bustedbenz · #14 09-24-2010, 01:29 AM

The most difficult thing about any exhaust work is the header bolts where the header bolts to the engine and the first section of pipe. Those bolts are RUSTY no matter what. And hard to get access to without universal joints (which make it harder to get the force where you need it) -- the heads tend to round off, and just generally be difficult (read: miserable) to remove. Some people have better luck than others but I fear those bolts more than just about any others on unknown cars. This may make junkyard hunting at DIY-junkyards difficult, though do-able.

That being said, I pulled the exhaust header off my 603 parts engine without much trouble. Had one of them that rounded off but I was able to get vise-grips on it. Far bigger problem were two stripped head bolts; had to fight one out with an impact wrench and an impact driver, and the other one had to literally be chiseled out. But that's another story.

charmalu · #15 09-24-2010, 02:32 AM

I use Kroil penerating oil on the rusty header bolts. spray them down and wait a bit for it to work, and they come right off. done it to a lot of PNP junkers as well as my own.

I will run circles around PB Blaster.

http://www.kanolabs.com/

Charlie