[first mercedes]

I know that i have a vacuum leak somewhere but I have no idea of where to look. I have the 300se. Would be grateful for some advice.

 

[Aussiemerc]

What doesn't work?

I know that i have a vacuum leak somewhere but I have no idea of where to look. I have the 300se. Would be grateful for some advice.

How do you know you have a leak- ie what doesn't work? There are different systems.

 

[first mercedes]

The car will not accelerate normally under 35mph (it's worse than grandma driving), and the transmission shifts really hard. It gets a little better when the car is warmed up but not much.

 

[foolio2]

First step is to get yourself a mityvac.

 

[Aussiemerc]

Vac problem

The car will not accelerate normally under 35mph (it's worse than grandma driving), and the transmission shifts really hard. It gets a little better when the car is warmed up but not much.

That narrows down the vacuum issue. Do you have a manual?.There are vac diagrams in it. If you don't have one I think you can download a freebie. I believe Mclare (spelling?)is the "manual guru".

MityVac mentioned above allows you to test each line to confirm it's holding/can hold vacuum.

 

[first mercedes]

I have a manual but i don't see a diagram for the inline 6 engine can anyone tell me if there is one?

 

[Teutone]

The 'new members please read, welcome....' announcement on top has the W126 service manual which includes the M103 engine. The vac diagram should be in there.
Otherwise, The W201 forum FAQ sticky has a manual with the M103 2.6 L which should be similar.
The announcement will also show how to search the forum with 'vacuum leak' etc on how to pin point vac leaks.

 

[Aussiemerc]

The diagram should be in section 14-050.That seems to be the common section in the manuals. Some manuals don't show the colors in English eg black may be Swartz, red Rot etc. The US one s/be English though.I've experienced difficulty because my RHD 107 has some colors different to US manual diagrams because of the difference in emission control. I have not closely inspected my V126 yet, but it's a 420.
Also, be aware that there maybe differences between year models (there are for 107's)
Good luck

 

[luckymike]

I've experienced the hard shifting. A vacuum line at the back of the engine had fallen off. I would check very carefully all around the engine to see if that has happened on your car.