Friend has 09 E350, which had classic exhaust manifold leak/tick.

Decided to attack the job, which ended up being the worst thing that I've done.
Every stud broke off as soon as I tried to remove exhaust nuts. Heating nuts with Oxy Acetylene until they were cherry red didn't help. Still broke off

After manifold came down, I kept welding washers/nuts to studs in most awkward positions. Generally first 2 attempts failed for each stud.
After 6-7 hours, I finally had all 7 out...

Now just waiting on used Manifold from California and new studs/gasket





I wouldn't wish this job to my worst enemy

 

I take it you live in the rust belt?

 

Been there, done that. You have my sympathy.

 

I would have to agree, that's one job i would giveaway to my indie! More power to ya.
R
2Merks

 

Very painful to even look at.

 

Curious if you tried soaking the studs with PB Blaster or similar for a day or so before attempting disassembly? I may be way off base here, but wouldn't heating things until visibly red turn them into butter, leading to inevitable breakage? Gentle heat (a few hundred degrees) has usually worked for me, in combination with a good penetrating oil and loosen/tighten/loosen some more/tighten a tiny bit/spin it off.
Water under the bridge, but maybe helpful later.

 

Definitely a rust belt car.

And no penetrating fluid would help here. Problem is that those sadistic German Benz engineers made the studs super thin
If you look at the how crusty those nuts/threads are, then you can see that nothing helps. And considering how thin studs are, no wonder they all broke off

Fun continued with this car.
I also had to change front left strut. First of all, had to disassemble everything to get it out and then, me and my friend thought we were going to die while compressing the spring with his Branick wall mounted compressor
Two pry bars on top to direct the mount over strut piston rod, while compressing the ultra strong spring all while fearing it will fly out.

 

That. Is. Brutal.

Well done. I imagine the expletives flowed as freely as the beer.

 

correct with the heat and PB blaster, sea foam deep creep makes a huge difference

 

To be honest, in my experience only thing that works is heat and beat (impact and oxy-acetaline)

 

How'd you go about removing the exhaust manifold? Did you have to drop the exhuast system?

 

I'm currently dealing with this issue right now on my W204 4matic. I bought a boroscope and taped a long straw extension to it so I could spray down every nut and bolt with penetrating spray for 2 weeks straight. I switched off between Liquid Wrench and PB Blaster. I managed to get one nut started which i think was removing the stud with it which is great and what I wanted but then the second stud snapped, though I swear it was coming out but i decided to tighten it back up then it snapped off. Thankfully i can tell there are still threads on the stud so its not broken flush with the engine. Vise grips?

I made a huge mistake of bringing the car to a local auto shop thinking they can hopefully do welding or other tricks to get broken studs out but instead they said they had to pull the engine. I said go ahead and just get it done. Thankfully they called me days later saying they dont feel comfortable doing the job. I picked the car back up and all they seemed to do was remove the section of exhaust after the manifold and remove the shielding over the front drive shaft and engine mount. But they left the shields off and didnt bother to give me back the bolts to put them back on. Also one of the metal clamps for the air box is missing which is ridiculous. And now I have a check engine light on for one of the O2 sensors.

Learned a valuable lesson not to bring it to just anyone. Thinking my only option is to bring it to a Mercedes dealer. Im sure they have dealt with this issue before.

 

The check engine light is due to the exhuast detached from the exhuast manifold. Heating up the bolt might free it up.

 

Check engine light turned out to be for the upstream O2 sensor. Code 0445 "output for heater of O2 sensor 1 bank 1 has a fault". Turns out that shop had damaged the upstream sensor AND they seriously installed them back into the wrong locations. They put the upstream sensor where the downstream belongs and down stream where the upstream belongs. I bought a new Bosch upstream sensor and installed them where they belong.

Downstream sensor installed in upstream hole:



Damaged upstream sensor installed in downstream hole:






I finally gave in and decided to bring it to Mercedes, dropping it off tomorrow to have the work done. Mercedes is giving me a loaner vehicle and they said they will install all the parts I have already. I went to an independent Mercedes/BMW shop and he refused to install any part that I bring in claiming he cant warranty the work, where I said thats fine I dont need a warranty I just want the work done. he still said no. Not including the exhaust manifold i spent over $100 just in hardware. A new exhaust manifold is over $400, I bought a used one in very good condition for $40.

Used exhaust manifold I bought for $40 and after I cleaned it up.



I noticed even more damage that shop did, instead of removing the large plastic undertray panels under the car to remove a metal brace they cut the panels away. Its mind blowing, the panels are just held on with a few 10mm plastic nuts, but they decided to cut them instead. I even have photos of the panels I took last year when I was replacing a few broken exhaust clamps so I know for a fact they are the ones that cut them.