Been trying to understand how this manifold works as i blocked my egr and have some issues later that i dont know if related or not.

 

So basically i had a turbo failure a year ago.

Had it replaced and blocked the egr with a plate.

 

Now the turbo kicks in late, 2500rpm,

At low rpm, when accelerating i get loud rattle in engine and black smoke that immediately goes away.

Only seem to happen at very low rpm in 2nd gear, comming out of a intersection.

 

Overall the car also doesnt feel as "sporty" as it did before the turbo failure.

 

However, this post was mainly me wanting to understand how the inlet manifold and egr works on this engine. Please help me with some insight

Pictures attached below for refference. Follow my numbers on the images.

 

What i noticed is that this manifold has a "throttle" flap at nr1 in the picture.

 

This is right where the turbo hose connects to the manifold.

What is this?

This thing is controlled by vacuum lines from (nr2)

And if i manually push the rod upwards (nr2) the engine chokes/flap closes.

 

This somewhat tells me its an egr flap??

Yes? No?

As if it were closed, but i did NOT blank my egr, then i guess car wouldnt choke as it still got "air" from the egr cooler? (which is now blocked)

 

So what is nr3? A sensor?

Also nr4 and nr5 seem to have some connection with this flap?

 

I ask because i am confused by the internet saying that the egr valve is electronically controlled and its unit is to the right/mid side of this manifold.

 

I am getting hung up on this vacuum controlled flap as i have a suspicion its messing with my performance and fuel/air ratio after blanking the egr.

 

The flap/vale is also wide open at idle, and seem connected to boost maybe? Which has me thinking it might close or partially close during boost and mess up performance?

Please give me some input.

Not all of the 1.8 TDCI's have the flap.  That's probably what's causing the confusion here.  The EGR valve is just the small electronic part at the right hand side.

You are right, that flap closes partially to restrict fresh intake air so that the full amount of EGR gas is drawn in to the engine instead.

It is vacuum controlled as you say.  And I suspect the sensor on top is a throttle position sensor measuring the flap angle (though not 100% without a clearer picture).

Number 4 is the MAP sensor, measuring boost pressure.

Number 5 is the vacuum solenoid for the flap.

 

Honestly, I'd just leave the EGR blank out.  You could try disconnecting the vac line to the throttle flap, but if it's being measured by a sensor, the ECU will see that and potentially trigger a fault code or limp mode.

32 minutes ago, TomsFocus said:

Not all of the 1.8 TDCI's have the flap.  That's probably what's causing the confusion here.  The EGR valve is just the small electronic part at the right hand side.

You are right, that flap closes partially to restrict fresh intake air so that the full amount of EGR gas is drawn in to the engine instead.

It is vacuum controlled as you say.  And I suspect the sensor on top is a throttle position sensor measuring the flap angle (though not 100% without a clearer picture).

Number 4 is the MAP sensor, measuring boost pressure.

Number 5 is the vacuum solenoid for the flap.

 

Honestly, I'd just leave the EGR blank out.  You could try disconnecting the vac line to the throttle flap, but if it's being measured by a sensor, the ECU will see that and potentially trigger a fault code or limp mode.

Thank you for the clarification.

This makes sense.

And i need the egr blocked because the cooler has a leak and with this old age i really dont wanna cash out a new cooler.

 

So i hoped i could mess with the vac lines to make the car have the flap wide open all the time considering the egr is now blocked.

 

If i just could find someone to code out the solenoid so it wouldnt trigger the code.

Is the solenoid only controlling the flap.

 

Or maybe i could modify the flap so that the sensor still could get readings, but the flap basically wasnt able to block anymore🤔

Confusing situation because the egr cooler is so broken, i couldnt reverse the egr block without a new cooler, and my budget passed looong time ago, when getting new turbo.

 

Old car. SMax 2006. With over 300k.

 

 

A used EGR cooler for these only costs about £20 on ebay UK.