1984 Euro W126 500SEL, Charcoal canister and CAT removal

[werminghausen]

I am working on my Euro 500SEL which was first delivered in 1984 to Germany (around Stuttgart). I was imported to the US (don't know when), a grey market car (was converted according US specs I guess) and
I am trying to convert it back to its original state.

I'd need your help for the charcoal canister and CAT removal.

Charcoal Canister: I see a metal line ending at the left side engine ba. That line is connecting to the charcoal canister with a rubber line.
I removed the canister now and removed the rubber line but don't know what to to with the remaining metal line.
Does anyone know how the original tank vent ended?

Also I don't know where to smaller rubber line was connecting to. Could have been connected to a vacuum line..
As this smaller rubber line was loose I don't know where it was connected to. Does anyone know.
I guess I need to cap the smaller open line as well.


CAT, o2 sensor
Then I read that the grey market car received a CAT and o2 sensor, also a frequency valve?
I think I saw remnants, a CAT and butcher-installed o2 sensor.
Any ideas on how to properly remove all these parts and convert back to original?

Thanks, Martin

[Frank Reiner]

w:

The european tank vent ended by the back of the rear footwell on the left side. You should find a junction at that point to the line that comes up to the engine bay. The OEM vent had a screen device on the end of it. The charcoal canister was vented to the throttle body.

Re: exhaust system. Is there a crossover pipe fron left to right above the bell housing? Or are there down pipes on each side that were then joined aft of the transmission to enter a cat?

[werminghausen]

Thanks Frank,
This is very helpful information. I'll follow the gas vent line back and will hopefully find the junction and take the front part off. I can put something on temporarily, a screen until I'll find something better, close to original.
I guess the line's screen was designed for creating a balanced atmospheric pressure for the air volume above the gas level? This means that mostly gas-air mix might come out or in rare occasions air move in.
Dirt should not enter the line...I guess a foam filter might work for the time being?

I was moving the 500SEL on the lift this evening and will have a look over the weekend and find this vent line.

The other smaller line to the air intake: I have lost that line. It was not on the car. The location where that line could have ended [at the air intake as you mentioned] could be at the right engine bank's valve cover rubber hose to the air intake. That hose (finger thick ID) as a small T for a vacuum line.
Is this vacuum line the small vent line connection from the charcoal canister?

Exhaust : I'll check how the two down pipes are connecting and take pictures.

I'll be back soon.

Thanks again, Martin

[werminghausen]

This is a picture of the right side cylinder bank with the rubber vent connection to the air filter housing. The blue dot is the T- connection which could be the
line connection for the charcoal canister.
Best, Martin

[werminghausen]

Frank,

here are a few pictures from today from under the lift.

the first one is the junction at the left side rear axle where the line was extended for the charcoal canister. I disconnected the old rubber extension.
Can I leave that end piece that you see in the picture? Is that the original part?

Then you see the exhaust. So yes there are the 2 down pipes and the lines where joined below the driveshaft cover. The cat was welded in place and the o2 sensor opening was plugged. Very crude cut out for the o2 sensor and electrical line. What was the idea of that cat?

What would you do with this cat?

Martin

[Frank Reiner]

Originally Posted by werminghausen

Frank, here are a few pictures from today from under the lift.
The first one is the junction at the left side rear axle where the line was extended for the charcoal canister. I disconnected the old rubber extension.
Can I leave that end piece that you see in the picture? Is that the original part?

Then you see the exhaust. So yes there are the 2 down pipes and the lines where joined below the driveshaft cover. The cat was welded in place and the o2 sensor opening was plugged. Very crude cut out for the o2 sensor and electrical line. What was the idea of that cat? What would you do with this cat?
Martin

The device on the vent line is a vent valve; it allows air to flow into the tank freely, but delays venting of vapors until pressure in the tank reaches some predetermined level. Although it is not original, it can remain.
The catalytic convertor was installed to comply with US emissions regulations. If the car is now exempt from MA emissions inspection the cat can be removed and replaced with sections of straight pipe (or an "H" pipe).

[werminghausen]

Thanks,

Vent Valve:
air moving freely into the tank: that means that valve would not allow for vacuum to build up in the tank (I have seen vacuum numerous time when air get sucked in after you open the tank cap.

Positive vapor pressure in the tank can build up until the valve opens: will hold some vapor pressure. That won't be much pressure I guess as the valve sits currently on the rubber hose without a clamp.

I removed the added line and built the area back to how it was roughly in its original state.

For the cat I think MA inspection did not care so far as the cat did not really work without the o2 sensor (That o2 sensor was removed and only a capped port and cable was left...because I passed inspection various times before.

I think I can remove that cat but wanted to check more closely.

Could it be that the cat is partially clogged and thus restricting the exhaust flow?
If this could be the case then it would be a bigger argument for removal.
If not then I can wait and remove it whenever I have time for exhaust renovation (there is so much on the renovation list already before I can have this car as a daily driver).

Martin