Engine: D5: Soot Filter driving me crazy...HELP !

[Bill_56]

Originally Posted by RoyMacDonald

It's certainly not part of the fuel injection system.

To be honest Roy, I'm mystified as to why you think that statement is relevant to anything I've said. I'm becoming more and more convinced that we are talking about different parts of the car, and so it may be best if I simply thank you for your attempts to help, which I'm sure were well intentioned.

Feel free to have the last word. But as it's such a friendly forum, let's agree to disagree without falling out?

[RoyMacDonald]

Originally Posted by Bill_56

To be honest Roy, I'm mystified as to why you think that statement is relevant to anything I've said. I'm becoming more and more convinced that we are talking about different parts of the car, and so it may be best if I simply thank you for your attempts to help, which I'm sure were well intentioned.

Feel free to have the last word. But as it's such a friendly forum, let's agree to disagree without falling out?

I was under the impression you thought it was for controling the air ratio which is controled by the injection system. Hence you appeared to me to be thinking it was part of the injection system.

Using a throttle to control the EGR gases is not something new for Volvo. That photo of a 2002 S40 engine I posted a few posts ago shows that.

The throttle valve on the D5 engine appears to be in the EGR return pipe from the exhaust to the intake.

I have the same thing on my pre DPF car but can't find a decent picture of it. No one seems to go further than cleaning the mixer plenum and it's in the EGR valve.

When mine eventually fails I'll take a photo of it.

Have you got your throttle replaced yet? I'd be interested to see if it was carboned up or a straight forward electrical fault?

[RoyMacDonald]

On removing the DPF Bill. I thought you really disliked it and thought it had no redeaming features, hence my suggestion, but I see you think it is worth keeping.

It's nice to know you're thinking about the enviroment.

[Bill_56]

There's a very nice diagram of the EGR & related parts in this document on the VOC website, at page 15.

http://www.volvoclub.org.uk/tech/New...-Technical.pdf

The distinction between Throttle Body & the EGR Throttle is clear to see, and I hope that is of some help.

Now, can anybody please confirm two questions for me...

(1) If the butterfly in the throttle body opposite the supply to inlet manifold, (item 8 in that diagram) is in the engine intake main airflow? If not, then I fail to see how any fresh air reaches the engine, which would be a serious design oversight that I suspect would have been noticed by now. But I may be missing something.

(2) If the same throttle body, item 8 (forgetting about the EGR throttle), was fitted prior to DPF-equipped cars (Euro IV, post 2005)?

Cheers,
- Bill

[Clan]

1 , Yes that butterfly IS in the main air flow .. from the air filter to manifold .

2, No it wasnt fitted to the original D5244T only when the engine was modified to the 185 bhp version in 2005 .

[chris vince]

One point I haven't seen mentioned so far (I may be wrong) re: DPF life, is that the use of an incorrect grade of oil will drastically shorten the life of a DPF.
Cars with these filters need a class 'C' oil, i.e. a low SAPS oil.
Unsuitable oils containing Sulphated Ash, Phosphorous, Sulphur will produce excess ash and block the DPF.
I cannot see the wrong grade of oil being put in at a main stealership (hopefully), but a smaller independent who may possibly stock a 205 lt barrel of 'fits all' oil could get it wrong.
Lastly re: EGR's, my opinion is block them off if possible.
I have on my wife's 2003 D5, and my Nissan Navara, without any problems at all, only clear benefits of cleaner oil, smoother running engines and very significant fuel savings.
Their only purpose is to reduce Nitrous Oxide (old fashioned Smog, London pea-soupers), if they weren't fitted manufacturers couldn't sell their cars in many countries and USA states, the real reason.
But, in reducing NoX the recirculated exhaust soot blocks up air inlet tracts, contaminates engine oil with excess soot (possibly another reason for DPF failures), thickens oil, blocks up oilways, scours out bearings, and generally shortens engine life.
Alongside strangling the life and performance of engines by denying them their lifeblood, clean fresh air.
An also very unwanted effect is the dramatic increase in fuel usage.
Just my two'penarth.
Chris

[RoyMacDonald]

Originally Posted by Clan

1 , Yes that butterfly IS in the main air flow .. from the air filter to manifold .

2, No it wasnt fitted to the original D5244T only when the engine was modified to the 185 bhp version in 2005 .

I take it there is some sort of valve though on the 163 bhp as the tech info says it is controlled by a solenoid instead of an electric motor on the 163 bhp, but mine dosn't appear to be in the main airflow. It is connected to it though. Or am I following the pipes incorrectly? My EGR gases look like they come from the exhaust through the cooler and into the inlet manifold. My version of the butterfly valve looks to be on the exhaust side before the main inlet so would only control the EGR gases, but by omission affect the air flow. ie exhaust gas replaces air.

For anyone thinking of removing the EGR flow. The engine will run too hot without the EGR gases. The engine is designed to work with them cooling the system and improving combustion.

Very usful document Bill Thanks.

[Clan]

some confusion again ,
yes there is a electronicaly controlled valve on both versions to control exhaust gas into the mixer unit , but the 185 bhp vesions also have an electronically controlled air throttle controlling the main air supply into the mixer unit from the air filter .. (the mixer unit is that cast alloy pipe on the front of the engine which the EGR is fixed to) The 163 bhp doesnt have an air throttle it gets a full supply of fresh air from the air filter at all times

[RoyMacDonald]

Sorry Bill I didn't realise your engine had an extra butterfly valve over mine. I take it your main air intake one has failed? Not the EGR one? In which case it's not going to be carboned up I would have thought, just electronic motor failure.

[chris vince]

[QUOTE=RoyMacDonald;886680]
For anyone thinking of removing the EGR flow. The engine will run too hot without the EGR gases. The engine is designed to work with them cooling the system and improving combustion.

Not quite right.
The only reason for the introduction of exhaust gases into the combustion chambers, is to reduce the amount of available oxygen and replace it with inert, dirty, sooty waste.
A by product of this is a reduction in combustion temperature within the cylinders.
Nox production, is dependent on the amount of oxygen available, and the temperature (higher) of the combustion process.
The engine will actually run cooler with a charge of cool fresh air drawn in through an intercooler (but will contain too much oxygen and produce too much Nox), rather than receiving a charge of hot exhaust gases.
Dirty exhaust gas is almost inert, it can't possibly improve the combustion process, which can only be done with oxygen that is present in air, hence the introduction of turbo and super chargers.
The more air that is forced into a cylinder the more powerful and hence efficient an engine will be.
Chris