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E55 2006
About two weeks ago, while driving I have noticed a hissing sound that resembled air from AC, but AC was off. The higher the RPMs were the louder the hissing got. I gave it a some throttle and car choked up, like it slipped a gear. No power, hesitation, hissing, and at low RPM rattling.
Was able to put the car on jacks and this is what I found. Rattling is coming from the exhaust Maybe one of the cats is dead, but can't make it out which one, left or right. Pulled part numbers: A2114901413, A2114901414, but nothing comes up under those numbers. However, what could be the cause of the the hissing, and why is car chocking?
That is one expensive repair! Suggestions as to what and where I can find a replacement. Dealer is charging $1800 for L and $1800 for R sides of the exhaust.
P.S. tried to upload a video, but getting an error. Hoping link will work.
https://youtu.be/YbmzKfGaeEw?si=wMUsNVIwkphh8BYP
Get the cats off and shake out what's in there. Could be bits of the catalyst broken off, or something else...
Shaking the pieces out would help the rattle, but it would not tell me why the car is chocking upon acceleration.
Could it be that the hissing I'm hearing is coming from the exhaust leak at the heads (if there is one there?).
I have had a catalytic convertor core fail in one large chunk. Partial throttle, the chunk lay in the bottom of the cat shell; full throttle the exhaust flow caused it to shift and block the exit.
You can use an infra-red thermometer or thermal camera to observe the convertors from underneath. A failed cat would stand out as a much lower temperature than normal.
Update:
Did a bit of investigating and found 2 exhaust leaks on a passenger side. One on manifold flange itself and one on a RT main cat. Also, it looks like a piece of cat has broken off and now rattling be the secondary cats.
Now need to find a reputable vendor for LTB all the way to the mid exhaust. Or a way to repair.
Now, I'm in search of affordable long tube headers with some cats and need to find a way to sell the OEM cats to recoup the cost of the headers. I remember seeing a thread in this forum (somewhere) with someone buying cats and paying premium dollar for it, but as of yet I haven't had any luck finding that thread.
I found this post intersting so i click on the link and found it was true that Walmart was selling headers for our cars at $350. That was yeserday, but I had not closed that window and find today the price is $1,153.99!
Update:
car is a daily for me. Been driving a couple of miles here and here to and from work. The hesitation and hissing are so bad now that I don't want to drive the car. Even the slightest of pressure on a throttle, the car sounds like it is about to have an asthma attack. 95% of power is gone! The fumes are getting inside the car, which gives me a headache. My own fault, I guess.
After speaking with a reputable tuner, find out that most places like VRP, German muscle, Becker, OBX and couple of others are out sourced from China. Yet the quality is decent on fitment and welds.
Right away I jumped on a Walmart website, to make a purchase, just to see the price jump from $350 to $1150. So, I went a different route. Fabtech.
While there were mixed reviews on customer service from fabtech-performance, I have had no such issues. Emailed them and got a pretty quick reply. Spoke with a gentleman named Neil. He was prompt to respond to questions, and even discounted a few $$$ off of their already on sale long tube headers. Had to get a catless set, as race cats were on a backorder. Order was placed @ 9am. By 11am order was shipped with a tracking number.
Purchased OEM manifold bolts, nuts, gaskets from online Mercedes store (at a great price). Got oxygen sensor extensions to fool the computer. Now awaiting arrival on all of the items.
Update:
Items arrived from fabtech-performance withing 5 days. Everything was packaged nicely. However one of the clamps was bent. Contacted seller and they sent replacements promptly. Some of the clamps were "evil energy" and some were non-banded. Even though both were the same diameter, "Evil energy" clamped on tightly, non- branded did not.
Long tubes and mid pipe with hardware
Now time to get OEM exhaust off. It was pretty straight forward without major hiccups. Two of the bolts had to be cut due to rust. Used a grinder for that.
Now, on with the new! Passenger side went in under 5 minutes, however, drivers side was a different story. Spent 2 days wiggling things, shifting things, moving things just to get the headers on the studs. Eventually everything went on and got tightened.
***Disclaimer: the headers flange (that sits against engine block) HAS to be leveled off through the entire surface or it WILL NOT sit flat entire surface, causing exhaust leaks.***
Replaced engine mounts while I was there. Made a mistake of thinking that I could put engine mounts after the headers were on. NOPE!!! Engine mounts, then headers. Be careful threading bolts into the mounts, as threads are aluminum and can be stripped super easy. Ask me how I know! 🤦Driver's side went on first, then passenger. Hard part over, right? Not exactly. I'm one of those people that doesn't like things being "an okay".
After getting everything lined up, I've decided to tighten the exhaust clamps to see if there will be any leaks. Sure enough. All but one clamping points had major exhaust leaks, which was the issue that got this whole mess started.
My two options: weld, or figure out how to seal the leaks.
Since car was on jacks and headers were already on the car, this made welding tough (considering I don't weld) and I didn't know any exhaust shops that I could trust the car with. Leaving me with only one option: figure out how to seal the leaks... so, to the drawing board.
After a few days of web surfing and pondering, decided to give grill gasket sealant tape a try. Can be found online. Found some from Academy Sports. Cut it in segments long enough to wrap around the diameter of the exhaust 3 times, enough to cover the cut slits, where the clamp is to be tightened. Applying that gasket created another issue. The clamp diameter was not big enough to go over exhaust and gasket material. To remedy the issue the wedged piece on the clamps has to be grined to allow extra space for the thickness of the grill gasket tape. With that gasket in place it eliminated 98% of the exhaust leak.
The next big issue that I had to address was the passenger side exhaust didn't have a flange, like driver's side did.
The vendor said that everyone just wedges it into the resonator's end of pipe. That's not good enough for me!
Had to cut the missing flange off of factory exhaust and weld it onto the replacement. Red line marked the areas when I had to cut and weld.
Doing so, allowed both of the ends to be tightened ono the resonator's end of exhaust.
Car is on the road and is awaiting a tune from RaceIQ.
The car is now way louder than I thought it would be! Don't know how so many go to a straight pipe on top of C63 mufflers. 😯
Now that everything is tightened, the exhaust is pulled all the way to the driver's side, causing the exhaust to push against the firewall, which in turn produces vibration.
Does anyone have suggestions as to how to better line up the exhaust, so it does not come in contact with anything on the body?
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