Xantia 1.9td EGR system?

howiedean · Post by **howiedean** » 16 May 2007, 20:44

I’ve been trying to work out how to improve the performance of my Xantia, see my other post on poor acceleration.

I would be very interested to know if anyone has a photo of the EGR system alternatively have a good description of how to disconnect it?

Thank you very much,

DickieG · Post by **DickieG** » 16 May 2007, 21:17

The EGR valve is controlled via a solonoid positioned on the bulkhead above the gearbox, there are two solonoids there, the other controls the idle speed. To disconnect the EGR valve simply pull the rubber hose off the solonoid.

I'm not sure that disconnecting the EGR will make much difference to performance because IIRC it only opens at idle speeds. However what you will achieve is stopping a horrible black slime being ingested into the engine which I understand causes problems at higher mileages.

Kowalski · Post by **Kowalski** » 17 May 2007, 11:16

The EGR system is irrelevant to the performance of the car, if the valve sticks open, its small diameter pipe compared to the manifold diameter so it can only "dump" a limited amount of your turbo boost pressure and do no more than that.

I remember fastandfurryous posting on here a while ago about a TD 406 that he removed the inlet manifold on and cleaned. Apparently the manifold was full of carbon and oil because of soot from the exhaust going through the EGR system and mixing with the oily residue thats found in your inlet manifold. I've looked inside my manifold and seen it thick with black gungy stuff, perhaps thats happened to yours too.

fastandfurryous · Post by **fastandfurryous** » 21 May 2007, 21:19

Kowalski wrote:I remember fastandfurryous posting on here a while ago about a TD 406 that he removed the inlet manifold on and cleaned.

You've a very good memory... that was the better part of 3 years ago (I think...!)

Indeed. EGR is a horrible device. Theoretically, it reduces the amount of oxygen in the intake charge of air at idle/low engine load, which in turn reduces the oxides of nitrogen emissions (a bit). It was introduced as part of Euro "2" emission regs in about 1997-ish IIRC.

It does also admit soot into the intake manifold, which mixes with the oil which all XUD engines have in their intake manifold (from either the breather, or the turbo, or both) and makes a right royal mess of the intake system.

The 406 I dismantled had literally a 1/4" thickness of this goop everywhere in the inlet manifod, the inlet ports, and all over the inlet valves. The intake ports had been reduced to about 1/2" diameter in places. It took for-****ing-ever to clean it all out.

My advice would be to physically remove the valve. Blank off the manifold ports and plug/remove the vacuum pipes that drive it all. Remove and clean out your inlet manifold too. EGR can only cause problems. The MOT emissions test is completely unaffected. (in fact you may perform better, as the car can now actually breathe properly)

A similar thing happened to a friend's Audi 80 TDI, so the problem is not PSA specific.

howiedean · Post by **howiedean** » 21 May 2007, 22:10

fastandfurryous wrote:
Kowalski wrote:I remember fastandfurryous posting on here a while ago about a TD 406 that he removed the inlet manifold on and cleaned.
You've a very good memory... that was the better part of 3 years ago (I think...!)

Indeed. EGR is a horrible device. Theoretically, it reduces the amount of oxygen in the intake charge of air at idle/low engine load, which in turn reduces the oxides of nitrogen emissions (a bit). It was introduced as part of Euro "2" emission regs in about 1997-ish IIRC.

It does also admit soot into the intake manifold, which mixes with the oil which all XUD engines have in their intake manifold (from either the breather, or the turbo, or both) and makes a right royal mess of the intake system.

The 406 I dismantled had literally a 1/4" thickness of this goop everywhere in the inlet manifod, the inlet ports, and all over the inlet valves. The intake ports had been reduced to about 1/2" diameter in places. It took for-****ing-ever to clean it all out.

My advice would be to physically remove the valve. Blank off the manifold ports and plug/remove the vacuum pipes that drive it all. Remove and clean out your inlet manifold too. EGR can only cause problems. The MOT emissions test is completely unaffected. (in fact you may perform better, as the car can now actually breathe properly)

A similar thing happened to a friend's Audi 80 TDI, so the problem is not PSA specific.

As I use a gloopy fuel anyway, I guess that the EGR will be caking up the intake manifold on my motor!!!
Do you happen to know if anyone has got an idiots guide on how to disable the nasty EGR system?
Any advice and I would be greatful.

Cheers

fastandfurryous · Post by **fastandfurryous** » 21 May 2007, 22:23

Disabling it will simply mean that the problem will not get any worse. To fix the problem:

Remove inlet manifold. Remove EGR valve (sortof comes out with the inlet manifold anyway).

Make up plate to blank off the exhaust manifold port (or fit earlier-type manifold). Make up plate to blank intake manifold (or again, fit earlier-type manifold)

If keeping the old manifold, wash it out with petrol, diesel, kerosine, pressure washer, gunk white spirit.... ANYTHING that gets the crap out of it.

Put it all back together.

Note how much faster the car now goes.

If you want to do a "complete" job, then really the head needs to come off, the ports cleaned out and the valves cleaned & reground in, but that's lots of work.

Eventually, what remains of the goop should slowly dissolve, and dissapear of it's own accord.

howiedean · Post by **howiedean** » 21 May 2007, 22:29

Fast reply fastandfurryous!!
Great I'll have a look at doing this job very soon. What needs to be considered regarding the vacuum pipes? I have already disabled the cold start system as this didn't work when I 1st purchased the car.

cheers

fastandfurryous · Post by **fastandfurryous** » 21 May 2007, 22:48

The vacuum hoses can be removed. I think I left the electrical solenoid connected on the 406, as it seemed to "know" that it wasn't connected, and throw up a fault, so the solenoid valve is still there, clicking away, just doing nothing.

The vacuum pipes were all removed. The vacuum "supply" came from a t-piece with some other vacuum system, so the t-piece was removed to make it look like the system was never there.

howiedean · Post by **howiedean** » 22 May 2007, 17:58

fastandfurryous wrote:The vacuum hoses can be removed. I think I left the electrical solenoid connected on the 406, as it seemed to "know" that it wasn't connected, and throw up a fault, so the solenoid valve is still there, clicking away, just doing nothing.

The vacuum pipes were all removed. The vacuum "supply" came from a t-piece with some other vacuum system, so the t-piece was removed to make it look like the system was never there.

One last question on this topic honest!!!!
If I simply disconnect the Vacuum pipes, how does the EGR valve react?
I wasn't if it would default on or off?

Regards

Howie....

fastandfurryous · Post by **fastandfurryous** » 22 May 2007, 18:58

If you remove the vac pipe from the EGR valve it will stay closed. Vacuum is applied to open it.

davethewheel · Post by **davethewheel** » 22 May 2007, 19:00

not sure myself how you would do the job correctly but when i first got my 2.1td xantia it was down on power and smoking badly due to the EGR valve sticking so i pulled of the rubber hose leading to it and stuck a bolt in it just to try it and it made a huge difference to the performance and stopped it smoking, it's been like that ever since

i had a look inside the manifold and it's completely caked in black goo

fastandfurryous · Post by **fastandfurryous** » 22 May 2007, 19:05

davethewheel wrote:i had a look inside the manifold and it's completely caked in black goo

TaDaaa....

....and for my next trick....

howiedean · Post by **howiedean** » 22 May 2007, 21:00

fastandfurryous wrote:If you remove the vac pipe from the EGR valve it will stay closed. Vacuum is applied to open it.

Ok I lied one more question. Closed is

and Open is 8) I take it?

Howie

fastandfurryous · Post by **fastandfurryous** » 22 May 2007, 21:04

No. The valve needs to be closed. It's when the valve is open (thus allowing exhaust into the inlet manifold) that the problem occurs.

With the valve closed, it's effectively a non-egr engine.

howiedean · Post by **howiedean** » 22 May 2007, 22:12

fastandfurryous wrote:No. The valve needs to be closed. It's when the valve is open (thus allowing exhaust into the inlet manifold) that the problem occurs.

With the valve closed, it's effectively a non-egr engine.

Thanks for that... I now understand the system a little more.

Cheers