Fuel Tank leak

[Zagato]

I'm not sure we are looking at the right part.

Which item number is it on page 2 of http://handbook.w116.org/Engine%5C107%5CM117_45%5C073-270.pdf

Michael

PS, I assumed a '1976 450SE since you didn't say it looks nothing like Tim's picture.

#24, Damper, and it's a 1974 model.

[13B]

Its an empty can, don't pay more the $2 for it at a MB breakers.  It works a bit like a air tank on your air compressor does.

$USD114 from the stealership is just ridiculous.

I.

[Papalangi]

I'm not sure we are looking at the right part.

Which item number is it on page 2 of http://handbook.w116.org/Engine%5C107%5CM117_45%5C073-270.pdf

Michael

PS, I assumed a '1976 450SE since you didn't say it looks nothing like Tim's picture.

#24, Damper, and it's a 1974 model.

I'm gussing you got one of these,

This goes up on the intake.  I'd follow 13B's advice and hit a wrecking yard.

Michael

[Zagato]

I'm gussing you got one of these,

This goes up on the intake.  I'd follow 13B's advice and hit a wrecking yard.

Michael

Ah, I'm glad I didn't order that part yet. Would've cost me $80.

Hope I'll find a salvaged 'empty can.' W116 are rather rare in Canada as I don't think they were officially imported here from Germany. Most W116's I see have imperial gauges like mine, as they're imported from USA dealerships. Oh well, W123's may have identical dampers.

But would it be okay to just bypass the damper and have the main fuel feed line go straight to the fuel pump? Would make it easier to cross the massive speed bumps over here without repeating the incident.

[TJ 450]

The damper is only as low as the fuel pump... it is protected by the diff and the spare wheel well, so damage from impact is unlikely inless you are driving off-road or the rear of the car is dragging along the road.  

The W126 also has the same damper.

Tim

[Papalangi]

I'm just south of Seattle, if you can't find one and we can figure out customs/shipping I can probably find a used one locally.

Michael

[Zagato]

Well, it's now fixed. With a new fuel filter too.

The last shop was useless, the damper was not the problem. The main fuel feed line as suggested before was the problem. Thanks to the independant Merc shop, they got it worked out in an hour. Unlike the last shop who sat scratching their heads for 3 days, telling me the wrong part was leaking, even though I told them to look at the main fuel feed line!

With that over and done with, I have a quick question.

The adjusting screw on the idle valve, next to the powersteering reservoir. Do you turn it clockwise or counter-clockwise to lower the warm up idle? Current warm-up idle is 1700RPM.

[Big_Richard]

The adjusting screw on the idle valve, next to the powersteering reservoir. Do you turn it clockwise or counter-clockwise to lower the warm up idle? Current warm-up idle is 1700RPM.

It sounds like your auxillery air valve is jammed open.

I wouldnt of thought even with this adjustment at maximum that you could even get close to 1700rpm's with a functional auxillery air valve.

[oscar]

Don't know if a 350 is any different but it can easily get to 2000rpm with an open AAV and idle screw.

Clockwise screws it in zagato and should lower RPM but my valve's stuck or slow again and it gives me the shits.  I've only used WD40 type penetrant sprays  but this time I'm going to go with what TJ recommended, carb cleaner. 

Good news on the fuel leak!

[pez]

Pull that air valve and soak it in carb cleaner.

What you see in that air valve will be what is inside your other vacuum hoses and your intake manifold. if it's gunky in there, then it's gunky everywhere.

If that's the case, pull it all [including upper & lower intake manifold], soak it all in carb cleaner for a day or so, the put it all back together.

[TJ 450]

I would only remove the intake manifold as a last resort... Murphy's Law states that at least one bolt will shear off and there will be coolant leaks afterwards because of pitting around the coolant ports.
Unless it is proven that there is a vacuum leak beyond the throttle body, it's a real case of "if it ain't broke, don't fix it", IMHO.

Speaking from experience, it's just one of those jobs that isn't really worth doing unless you remove the heads for reconditioning as well, or there is a proven leak.

Normally, all that's required is getting everything from the air cleaner up to and including the throttle body up to scratch and possibly running a carbon cleaning system through the intake. On a D-Jet car, this should be fairly straight-forward, as there isn't much to contend with.

Tim

[Big_Richard]

Its an empty can, don't pay more the $2 for it at a MB breakers.  It works a bit like a air tank on your air compressor does.

$USD114 from the stealership is just ridiculous.

I.

Incorrect, I examined my new one sitting in my parts box awaiting installation, there is a diaphragm at one side of the cylinder housing, the one with the crimped on and soldered edge. seems also to be spring loaded.

[koan]

Incorrect, I examined my new one sitting in my parts box awaiting installation, there is a diaphragm at one side of the cylinder housing, the one with the crimped on and soldered edge. seems also to be spring loaded.

You're right PB, I just dug out the new one I didn't use (126 470 0116),  there is a diaphragm in there, feels like a thin flexible metal shim with foam behind it. Think I've seen it called an intake noise damper.  Wonder if the old type is the same.

koan

[Big_Richard]

Incorrect, I examined my new one sitting in my parts box awaiting installation, there is a diaphragm at one side of the cylinder housing, the one with the crimped on and soldered edge. seems also to be spring loaded.

You're right PB, I just dug out the new one I didn't use (126 470 0116),  there is a diaphragm in there, feels like a thin flexible metal shim with foam behind it. Think I've seen it called an intake noise damper.  Wonder if the old type is the same.

koan

clearly it does something, because i recall reading somewhere that when it fails doing what its supposed to do, one can end up with a destroyed fuel distributor.

I suspect the old big versions (discontinued over a decade ago) did have something in them that has probably perrished, and "good second hand" ones that were used, were infact just as shithouse as the ones they were replacing

[koan]

clearly it does something, because i recall reading somewhere that when it fails doing what its supposed to do, one can end up with a destroyed fuel distributor.

Can't see how the fuel distributor could be damaged, The chamber is on the low pressure  pump inlet, the fuel accumulator is on the pump output. There's a pressure damper associated with the warm up regulator and fuel distributor at the back of the engine, that could be what you read about.

I think its something to reduce fuel pump noise.

koan