I understand that exhaust runs through the EGR. what I don't know is:

Does the EGR valve control the amount of exhaust into the air intake?

If so, does only the amount of exhaust let through the valve go through the EGR?

if so, if the EGR valve is closed then no exhaust will go through the EGR?

thanks!

 

Yes, yes, and partial yes. A closed EGR valve will eliminate flow through the cooler, but gas will still be present in the cooler. A failed cooler could still let exhaust gas into the coolant side despite the valve being closed.

 

So if the EGR cooler has or is not failed then exhaust gas will not flow through the EGR cooler?

 

I actually thought it was the other way around? The EGR valve is closed, but even so there is Coolant on the other side of the EGR cooler, and if the Cooler fails it can still allow coolant into the intake...

Scott

 

The egr cooler is a heat transfer mechanism that always has coolant flowing through regardless of a lot of exauster gas or a little. If the egr cooler has not failed, coolant does not mix with intake nor exhaust gas into coolant.

if the egr valve is closed is there any exhaust gas flowing through the egr cooler?

if there is no exhaust gas flow then it seems to stand to reason there is little to no heat transfer, cooling, and therefore little to no stressing of the egr cooler component.

if there is always exhaust gas flowing through the EGR cooler regardless of egr valve position being open or closed, then there is always stress on the egr cooler.

 

The gas is always there regardless if the valve is open or closed. The gas comes from the uppipe into the cooler then to the valve in the manifold.

 

So a closed valve does not create a dead head of pressure that prevents flow of exhaust gas? There is an outlet for the gas other than the egr valve that allows gas flow through the egr cooler?

 

The pressure in the cooler will be what you see at the EBP sensor. But it is deadheaded so to speak but the rest will go into the turbo and out the exhaust pipe.

 

The exhaust goes in the top side of the picture the out the bottom of the pic into the manifold from there to the valve and back into the intake.

 

It is deadheaded but you will always get some heat transfer as the coolant flows and cools down the gas at the exchanger surfaces its density increases and hot gasses rise. It probably isn't much, but it is some (especially considering how the cooler is oriented).

 

My apologies to packagerjr: you had it right, and I was the one thinking of it backwards: EGR valve letting flow INTO the cooler, NO it let's flow INTO the intake!

And all ya' gotta do (Scott speaking to himself) is look at where the damn valve is!!!

 

No problemo. no apology needed!