Recirculation valve focus tdci help

[Damien]

Hey all, hope you all well newbie here needing little help needing to find the recirculation valve on my 1.8 tdci 2007

any help would be appreciated or pics of the location.

[Tdci-Peter]

I guess you mean the EGR (Exhaust Gas Recirculation) valve.

It is the big lumpy thing at the top of the back of the engine, partly under the plastic grille. It is partly built in to the inlet manifold.

I had to fix mine, was giving EGR related DTCs, and little power dips.

See

Focus-EGR.pdf

For quite a bit more info. Or post another query here. No guarantee of immediate answer though!

You will find lots about it on this site, it is a troublesome thing.

Peter.

 

[Damien]

Hi Peter thanks for reply, if am right is this the part that's comes off the 90 degree turbo hose?

just above the water reserver tank

[Damien]

Hi Peter only reason asking is to fit this, but looking at the egr it don't look right to attach it too.

 

[Tdci-Peter]

Hmm, not quite sure where that needs to go.

Pic of whole inlet manifold (Mk2, 1.8TDCI) below. ("Borrowed" off eBay, courtesy of The No1 Car Parts Centre)

The small flanged hole facing you is the connection for the exhaust gas from the EGR cooler.

The large hole at the far right (facing right) is the air intake from the intercooler. The big hose near the coolant reservoir is the hose from intercooler to this port on the inlet manifold.

And the four downward pipes go to the cyl. head.

The pipes and hose from the turbo to the intercooler are harder to see, it runs under the air filter. The turbo is quite hard to see on this car, it is under the EGR valve and other bits.

I guess this unit goes in the pressurised pipes from turbo to inlet, probably does not matter where if is just to de-pressurise the system quickly on demand. So anywhere in that hose run where it fits will do, I expect. (The pipe from turbo to intercooler is a bit smaller than the one from intercooler to inlet manifold though.)

[Damien]

Hi Peter, spent half hour looking last night and no idea, just got your post now which has made even more sense 👍 Will have look in bit and see.

if not will just pop to local garage n ask where needs to be lol

[iantt]

there is no recirc valve on your 1.8 diesel.

[Damien]

Ohh right thanks for that, guy on eBay said fits my car grrrrr been to garage who done all my tuning and they don't know where it goes.

 

looks like I be returning it

[Tdci-Peter]

Following Ian's answer, I have just looked up "recirc valve", and the EGR valve is a red herring!

********** From LaurenceFrost on PistonHeads:

Dump valves come in to flavours: recalculating and atmospheric.

Upon lifting off the throttle (after giving it some), the throttle plate is slammed shut so that very little air can get into the cylinders. This means that you have full boost pressure built up, and nowhere for it to go. Air will always try and uncompress itself, so it looks for the easiest escape route.

This escape route is the turbo (where the air has just come from)! The air can now escape this way because there is no longer any exhaust gas driving the turbo (foot is off the throttle remember). Even though the turbo is not being driven at this point, it will still be spinning incredibility quickly, but the compressed air going back through it the wrong way will slow it right down (and can actually damage it in extreme cases).

The atmospheric dump valve works by opening when the throttle is lifted (I ll explain exactly how it knows when to open if anyone is interested). The easiest escape route for the air is no longer the turbo s compressor housing, but the dump valve that has just opened. The woosh is the air escaping. The turbo will still be spinning nice and fast, and a lot of the lag between changing gears will be eliminated.

The recalculating valve works just the same, but is much quieter (although some air still escapes back through the air filter). The excess boost is routed back to the piping just before the turbo, so the pressure goes back through the system, which eliminates more lag than the previous method, and still relieves the strain on the turbo between changes.
 

************** End of quote.

So all is (fairly) clear. A diesel does not have a throttle. When you lift your foot, all that happens is the injectors shut down, no fuel, but full air flow continues. (The turbo vanes or wastegate will also open.) The lack of engine braking, caused by a throttle, is very noticeable on a diesel .

Therefore there is no build up of pressure, and no tendency for the turbo to stall or surge. No need for a recirc or dump valve.

I notice appreciable turbo "after-boost" on my car. If you lift your foot slowly after full power, there is a (slightly disconcerting!) increase in power for a while. This is due to the inlet air pressure continuing after the vanes have opened to release the exhaust back pressure. It is the opposite of turbo lag.

 

 

[Lenny]

On Thursday, June 02, 2016 at 10:11 PM, Damien said:

Hi Peter only reason asking is to fit this, but looking at the egr it don't look right to attach it too.

 

😀😅😂😭👍

Diesel turbo is very different to petrol they don't spool the same, 

Modern diesel engines have variable vain turbos making them more efficient and dont create excess boost for blow off valves.

 

Don't fit that to your egr valve or you will most definitely gas yourself to death 😁

[iantt]

ive got to admit it did make me smile when i read this thread , every day is a learning day. lol

[Damien]

Thanks for help guys seen this on Internet attached to a diesel car so thought would work.

any you guys know what to put on for decent dump sound 

[Lenny]

38 minutes ago, Damien said:

Thanks for help guys seen this on Internet attached to a diesel car so thought would work.

any you guys know what to put on for decent dump sound 

I genuinely apologie for the laughing mate In my six years on here ive never jeered anyone and i wasn't ever laughing at you, just the idea not you as an individual were all here to learn and relay information.

The thing is; diesels don't need dump valves, I too would love to have one but diesel turbo doesn't need a blow off valve to prevent cavitation in the casing of the turbo; which is a blow off valves true purpose is to release pressure when clutch is pressed to prevent the compressed air from pitting the cast iron compression housing.

you could fit a saber electronic dump valve 👌

 

[Damien]

No offence taking mate, only reason want 1 is just love the sound of them n know some diesel cars have them fitted n sound mint.