Andrew Camarata

[MinnesotaEric]

And it takes an edge case to cause vacuum on a turbodiesel.

Aaron Z

I've only taken a sip of my first coffee today, so not all of my switches are flipped on yet, but I'm not following what you're trying to explain to me.

 

[deezler]

That a modern turbodiesel engine rarely has any intake vaccuum.

I dunno about "edge case" though, zero accelerator pedal coast-down will definitely have a little vaccuum, and sitting at a steady idle speed will too. Just not anything close to a gasoline engine with a throttle plate.

 

[4570Man]

That a modern turbodiesel engine rarely has any intake vaccuum.

I dunno about "edge case" though, zero accelerator pedal coast-down will definitely have a little vaccuum, and sitting at a steady idle speed will too. Just not anything close to a gasoline engine with a throttle plate.

My old 7.3 truck has an aftermarket boost gauge installed which is the first diesel I’ve had to have such a thing. The boost gauge sits at zero when it’s not accelerating or going up hill.

 

[deezler]

I suppose it can depend on the motor. If the turbo geometry or programming is such that it still pumps a little air, easy to stay at positive pressure under no load.

My VW diesel would go just a little negative under no load; the cylinder intake strokes are sucking air in past a filter, makes sense there would be a little vacuum if the turbo isn't making any boost.

 

[4570Man]

I suppose it can depend on the motor. If the turbo geometry or programming is such that it still pumps a little air, easy to stay at positive pressure under no load.

My VW diesel would go just a little negative under no load; the cylinder intake strokes are sucking air in past a filter, makes sense there would be a little vacuum if the turbo isn't making any boost.

My gauge doesn’t have the capability to read vacuum and it’s not a high precision instrument to start with. It would be interesting to see when it pulls a vacuum vs the turbo is equaling the intake.

 

[MinnesotaEric]

My old 7.3 truck has an aftermarket boost gauge installed which is the first diesel I’ve had to have such a thing. The boost gauge sits at zero when it’s not accelerating or going up hill.

No vacuum?

Years ago when Ford came out with the first eco-boost in their F150 and the engines started hydraulically locking because water would accumulate in the intercooler, and then slug the engine, I suggested drilling a 1/16" weep hole on the lowest lefthand portion of the intercooler to let water out.

After all, every intercooler before canister emissions came with a factory weep hole in their intercoolers for that reason but Ford couldn't because the brave, new world is more interested in saving the children than good design and reliability.

The internet blew up on me. It'll suck crap into the engine, they cried.

Clearly, they didn't understand what a turbo does. Eventually, I made a video that showed the intercooler was never under vacuum.

Now, if the hole isn't a small hole, but a larger hole, you can get scavenging which could draw outside air into the intake through a hole in an intercooler.

 

[4570Man]

No vacuum?

Years ago when Ford came out with the first eco-boost in their F150 and the engines started hydraulically locking because water would accumulate in the intercooler, and then slug the engine, I suggested drilling a 1/16" weep hole on the lowest lefthand portion of the intercooler to let water out.

After all, every intercooler before canister emissions came with a factory weep hole in their intercoolers for that reason but Ford couldn't because the brave, new world is more interested in saving the children than good design and reliability.

The internet blew up on me. It'll suck crap into the engine, they cried.

Clearly, they didn't understand what a turbo does. Eventually, I made a video that showed the intercooler was never under vacuum.

Now, if the hole isn't a small hole, but a larger hole, you can get scavenging which could draw outside air into the intake through a hole in an intercooler.

It doesn’t have a vacuum gauge to know.

 

[spitter]

It's only pressurized when it's running. When it sits a hole in the intake anywhere depending on the size mice, bugs, salt spray, dust, anything will find its way in there. If it was me, I would fix it as soon as possible. But my stuff doesn't look like his.

 

[lman]

Neat trip to MT.

 

[mcfarmall]

No vacuum?

Years ago when Ford came out with the first eco-boost in their F150 and the engines started hydraulically locking because water would accumulate in the intercooler, and then slug the engine, I suggested drilling a 1/16" weep hole on the lowest lefthand portion of the intercooler to let water out.

After all, every intercooler before canister emissions came with a factory weep hole in their intercoolers for that reason but Ford couldn't because the brave, new world is more interested in saving the children than good design and reliability.

The internet blew up on me. It'll suck crap into the engine, they cried.

Clearly, they didn't understand what a turbo does. Eventually, I made a video that showed the intercooler was never under vacuum.

Now, if the hole isn't a small hole, but a larger hole, you can get scavenging which could draw outside air into the intake through a hole in an intercooler.

I followed your advice years ago, Eric the Oracle, and never had any issues afterwards.