Car breakdown issues directly after garage service - garage not taking responsibility

Goudy

paul_c123 said:

Except the throttle flap.

In a diesel?

No, rpm is controlled by the amount of fuel injected not by the control of air.

There is no throttle or throttle flap in a diesel. It draws in air as it needs, there's nothing between the outside and the cylinders except an air filter and perhaps a turbo.

WellKnownSid

Goudy said:

paul_c123 said:

Except the throttle flap.

In a diesel?

No, rpm is controlled by the amount of fuel injected not by the control of air.

There is no throttle or throttle flap in a diesel. It draws in air as it needs, there's nothing between the outside and the cylinders except an air filter and perhaps a turbo.

Thought all diesels had throttles these days.  Shuts the engine down cleanly and helps with turbo / EGR behaviour I believe.

Goudy

WellKnownSid said:

Goudy said:

paul_c123 said:

Except the throttle flap.

In a diesel?

No, rpm is controlled by the amount of fuel injected not by the control of air.

There is no throttle or throttle flap in a diesel. It draws in air as it needs, there's nothing between the outside and the cylinders except an air filter and perhaps a turbo.

Thought all diesels had throttles these days.  Shuts the engine down cleanly and helps with turbo / EGR behaviour I believe.

Yes, some have anti shudder valves as part of their emissions systems. Under low load, diesels tend to be very dirty (NOx) so the valve helps increase EGR flow at lower engine load/rpm.

They move at lower engine load/rpm to create a pressure difference to help suck the recirculated exhaust gas back around into the intake..

There can also be a lot of unwanted NVH at shutdown, so these can also work as an air restrictor when shutting the engine off.
When turning off they will alter the air to a lower, smoother flow which helps shut off without the engine stumbling on or shuddering.

They don't control the rpm though like a petrol engines throttle.
A diesels rpm is controlled by how much fuel is injected.

They may or may not help with run away.
If a diesel is ingesting it's own oil and screaming it's head off at max rpm, even if the valve completely shut it will likely find a source of air. The tiny 12v motor and it's plastic gear wouldn't stand of holding that back either.

Insane Runaway Diesel