Thread: Smoky D4 video

With car idling I just tried completely covering the side intake with heavy rubber swim caps and a damp towel over the top of them.

Literally no restriction and not even enough vacuum to hold the swim caps onto the intake against gravity.

Not going to stop a runaway engine this way.

It would've helped if the driver had tried, for example, turning it off. Modern diesels have got throttle flaps on the intake manifold. Its used to create a pressure drop to increase EGR gas flow. It also closes at engine shutdown to choke off the air supply so the engine doesn't rock back and forth like old diesels did.

Originally Posted by PerthDisco

Justin, If you could block the side air intake (not sure if D4 has two) with a pillow or flat cardboard (or even one half of your backside) would it be enough to kill it or can it still suck enough air between intake and air cleaner box to keep running?

I know the Detroit 2 strokes were famous for this but thought it was very hard for a normal diesel to run away?

Edit: it would possible to check this solution on a non runaway engine

I doubt this would work. The pipe running through the wheel arch between the air intake grill and the filter box is not sealed so air would still be drawn in. This pipe is replaced with a sealed pipe on the Safari snorkel.

Originally Posted by Oztourer

I doubt this would work. The pipe running through the wheel arch between the air intake grill and the filter box is not sealed so air would still be drawn in. This pipe is replaced with a sealed pipe on the Safari snorkel.

I tried my Safari earlier with a shopping bag but was foiled by the rain drains in the snorkel head letting in air. You’d need a long heavy bag if it would work at all. I believe there might also be a water drain in the air box as well that needs closing off. All in all, still difficult.

Originally Posted by Beery

It would've helped if the driver had tried, for example, turning it off. Modern diesels have got throttle flaps on the intake manifold. Its used to create a pressure drop to increase EGR gas flow. It also closes at engine shutdown to choke off the air supply so the engine doesn't rock back and forth like old diesels did.

Was thinking the same thing!
Are you sure the intake buttefly and egr valves all close on shutdown?
Surely the driver would have thought to push the off button...

Originally Posted by northiam

Was thinking the same thing!
Are you sure the intake buttefly and egr valves all close on shutdown?
Surely the driver would have thought to push the off button...

The throttle body is opened at some stage once shutdown as whenever I have worked on mine the throttle is always found at the wide open position. If it does close, it’s only temporary.

Originally Posted by DiscoJeffster

The throttle body is opened at some stage once shutdown as whenever I have worked on mine the throttle is always found at the wide open position. If it does close, it’s only temporary.

Yeah I think you're right. Throttle is normally open and Im pretty sure EGR valves are normally closed.

Oh nasty..... had it just been serviced at a dealer? (personal option only).

As for blocking intake with rags/bags/towels etc etc... not a hope in hell, my guess is that there would be that much intake suction anything that was put over intake would cleanly get sucked in.... with your undies

Regards
Daz