Xantia HDi smoking

Post by **DHallworth** » 23 Jan 2011, 23:10

Thanks for the advice guys.

Is the EGR valve the thing that sits on the inlet at the back by the bulkhead? The thing that's held on by 2 nuts and is a sod to get on and off!

It's got a metal pipe that comes out of the side and has a rubber pipe that goes onto it?

Are there any problems likely to be caused by completely blocking it off?

Is there any easy way to measure the boost that it's producing?

David.

dieselnutjob · Post by **dieselnutjob** » 23 Jan 2011, 23:20

it sits on top of the exhaust manifold and has a shiny metal pipe that runs across the back of the cylinder head and joins the inlet manifold with two bolts
there is also a small bore rubber pipe which is the vacuum that actuates it

to measure boost
either
1. boost guage
2. if it has Bosch injection any EOBD scanner that does live data, or a Lexia
if it has Seimens injection, a Lexia

Post by **DHallworth** » 23 Jan 2011, 23:29

Ahh, didn't realise I could monitor the boost pressure using the Lexia!

That's ideal!

Will have a look at it tomorrow and let you know what I can find.

Thanks again!

David.

citroenxm · Post by **citroenxm** » 24 Jan 2011, 07:56

Of course you can D, goto the Parameter Measurements section...

Shows you ALL sorts of live info in there...

These EGR's come off a bit easyer then the old of XUD due to the slightly more efficient engine design. IIRC its only 2 10mm bolts hold the EGR on the top of the exhaust manifold, and two 4mm allen head bolts hold the metal pipe to the edge of the inlet manifold...

Paul

Post by **RichardW** » 24 Jan 2011, 07:59

If you suspect a dodgy remap, fit the ECU off the other car and see if it improves?

citroenxm · Post by **citroenxm** » 24 Jan 2011, 09:55

Is that possible?? I thought all three Items, the Key, Body computer and ECU were all matched together as one?? Or is it just the Key and Body computer that work together to unlock the ECU?

Paul

Post by **RichardW** » 24 Jan 2011, 09:56

Not sure...I wrote it then a bit later thought maybe not! DickieG fitted a new ECU to his the other week, not sure what was involved in getting it to play though

citroenxm · Post by **citroenxm** » 24 Jan 2011, 09:59

Not a problem with a Lexia Im sure....

Paul

Post by **DHallworth** » 24 Jan 2011, 11:08

The other thing I've got is a KWP flasher so I can actually copy the map file from one car to the other rather then changing the ECU's.

You back the smokey car up, then rewrite it with the good cars file.

If it solves it great, if it doesn't you've still got the old file you can put back on.

Cheryl is bringing the car down this afternoon before she goes to work so I'll report back once I've had a fiddle.

David.

dieselnutjob · Post by **dieselnutjob** » 24 Jan 2011, 11:15

I don't think it's the mapping.
If someone had "chipped" it to put more fuel in this would only affect it at full power. Even a massively overfueled diesel is running very lean at idle, and this car clearly has a problem even at idle.
It's either
a: retarded injection timing
b: lack of oxygen
c: one or knackered injectors
d: burning oil
e: lack of compression

to go through the options
a: the timing is electronic and controlled by crank and cam position sensors. If either were missing you would get a warning light or possibly a non start. If the cambelt was out causing a bad timing on the cam sensor the ECU would complain about lack of sync between the sensors
b: a stuck open EGR valve will starve the engine of clean air which is why I suggested disabling it
c: if an injector is opening when it shouldn't I would expect a very knocky engine. It would sound like pinking. If you have this then correct it as eventually it can burn a hole in a piston
d: oh dear. still I guess you would notice the oil level dropping?
e: oh dear

Post by **DHallworth** » 24 Jan 2011, 18:03

Well I spent this afternoon messing around with the Xantia.

I fabricated 2 metal plates and used them to blank off both ends of the EGR valve.

Is leaving these plates in place going to cause any long term problems with the car?

Once fitted I started the car and took it for a run, unfortunately it was dark so I didn't get a chance to properly monitor the smoke until I got home.

I'm used to driving a 406 HDi 90 and by comparison this 110 Xantia feels like it's flying. I also started our SX and listened to them running side by side to compare. I wouldn't say one of them sounds noisier then the other.

The car that smokes does have a bit of injector rattle, my 306 did this also but it didn't smoke at all. I believe this is common on the HDi's though.

Another thing I noticed today was if I took the oil filler cap off with the engine running there was a puff of smoke that came out of that. It sounded almost like it was breathing through the oil filler.

I'm just about to go and stick it on the Lexia to see what the boost pressure is running at too.

David.

DickieG · Post by **DickieG** » 24 Jan 2011, 18:08

citroenxm wrote:Is that possible?? I thought all three Items, the Key, Body computer and ECU were all matched together as one?? Or is it just the Key and Body computer that work together to unlock the ECU?

RichardW wrote:Not sure...I wrote it then a bit later thought maybe not! DickieG fitted a new ECU to his the other week, not sure what was involved in getting it to play though

Prior to fitting the new ECU I was of the opinion that as per the Citroen diagnostic manual the ECU needed to be coded to the Body Computer and key but now I'm not so sure as at no time through initialising the ECU was the four digit immobilser code required. The process consisted of selecting whether the car was fitted with single or 2/3 speed cooling fans, whether cruise control was fitted and other similar factors, hence why I'm now not so sure, there is of course one definite way of finding out,,,,,,,,,

Post by **DHallworth** » 24 Jan 2011, 19:56

Well, I've had a session on the Lexia earlier and got the following:

Turbo Pressure Measured: 2014 millibar
Turbo Pressure Setting: ~2000 millibar

2014 millibar is just over 2 bar.

That's around 1 bar more then what it should be isn't it?

David.

DickieG · Post by **DickieG** » 24 Jan 2011, 20:09

What were the circumstances the engine was running under? Idle or under load and at what revs etc.

Post by **DHallworth** » 24 Jan 2011, 20:12

When it was giving those readings the engine was at wide open throttle in 2nd gear.

The readings were the same wether the car was accelerating up hill or accelerating on the flat.

David.