1993 Mercedes w124 diesel modifications

[SkauneJohan]

Did my first engine modification yesterday, removal of throttle plate(this is a diesel engine)

People I talk to say it is purely for creating vacuum to activate EGR nothing else, since this car was imported it has EGR, many same engine and yearmodel cars were built without this.

This is how it looked like before


Nice, finally gone and yuk full of soot from the EGR


End result


And what can I say after driving 160km(100miles)
WOW!!! never thought it would make this big difference, she has a lot less engine braking so I can coast a lot longer (automatic transmission) and partial throttle response is a lot better,
in fact partial throttle response is so much better that I can leave her in D instead of manually shift to 3rd gear when city driving at the speeds 30km/h and 40km/h.
Same thing in roundabouts no need to use kickdown(or manually downshift) to get her initally moving out of the roundabout, she scoots a lot quicker with less throttle input (or rather the need for full throttle in city driving is gone now)

Another positive is that engine stays cooler, before even during the winter short idling in traffic lights made temp go quite high and it was slow to go down to normal again, now it is slow to rise and fast to go back to normal

The bigger question is, how will this affect fuel consumption my guess is probably for the better

[cRiPpLe_rOoStEr]

What about the effect of this mod to the brakes? Aren't them vacuum-assisted too? On a sidenote, in Brazil I'm aware some people adapted throttle plates to Mercedes-Benz OM-314 engines in order to improve engine-braking, even though I would rather resort to an exhaust-brake for that matter.

[SkauneJohan]

Originally Posted by cRiPpLe_rOoStEr

What about the effect of this mod to the brakes? Aren't them vacuum-assisted too? On a sidenote, in Brazil I'm aware some people adapted throttle plates to Mercedes-Benz OM-314 engines in order to improve engine-braking, even though I would rather resort to an exhaust-brake for that matter.

No effect at all on brakes
like all diesel engines this also has a vacuum pump for the brakes and since it is older style mercedes, this vacuum is used for central locking mechanism and engine shutof also

Like I wrote above this engine was also made without EGR, only difference is intake, exhhaust, a few linkages and pipes between exhaust and intake

So this throttle plate only function is to allow intake get clogged with soot from EGR

Later I will get the non EGR exhaust manifold and intake to increase efficiency even more and make room for water injection (this EGR intake is also very big and makes engine bay crowded)

[jakobnev]

Isn't it going to fail inspection if you disable EGR?

[SkauneJohan]

Originally Posted by jakobnev

Isn't it going to fail inspection if you disable EGR?

Here no, but depending on where you live it might, the egr is still there and everything around it

the thing with EGR on diesel is that if you want it to work it needs cleaning from soot almost once a year, google if you wish to learn more

[California98Civic]

Does water injection work in a diesel?

[SkauneJohan]

Originally Posted by California98Civic

Does water injection work in a diesel?

Of course it is great on supercharged engines but even NA benifit from it, reduces soot and NOx, cleans combustion chamber

The downside is that water freezes during winter

[cRiPpLe_rOoStEr]

Adding some alcohol prevents the water from freezing, plus it becomes easier to vaporize.

Originally Posted by SkauneJohan

like all diesel engines this also has a vacuum pump for the brakes and since it is older style mercedes, this vacuum is used for central locking mechanism and engine shutof also

Since it had a throttle plate, it got me wondering if Mercedes-Benz would've eliminated the vacuum pump.

[SkauneJohan]

Originally Posted by cRiPpLe_rOoStEr

Adding some alcohol prevents the water from freezing, plus it becomes easier to vaporize.

Since it had a throttle plate, it got me wondering if Mercedes-Benz would've eliminated the vacuum pump.

Yeah i know, methanol is the preferred alcohol, it even adds some energy (power) problem here is it is very very expensive, only cheapish alcohol is E85 and then you gotta remove the gasoline after blending it with water.... only other solution is washer fluid wich also is ethanol here and quite expensive


My though was that they maybe also used the vacuum for the automatic gearbox but they did not, it seems to be only EGR wich is nice

[cRiPpLe_rOoStEr]

Originally Posted by SkauneJohan

Yeah i know, methanol is the preferred alcohol, it even adds some energy (power) problem here is it is very very expensive, only cheapish alcohol is E85 and then you gotta remove the gasoline after blending it with water.... only other solution is washer fluid wich also is ethanol here and quite expensive

Is homebrewing vodka totally out of question?

My though was that they maybe also used the vacuum for the automatic gearbox but they did not, it seems to be only EGR wich is nice

So, does its torque converter not feature a lock?