| Home  Blogs Help Search Login Register  
« previous next »
Pages: 1 [2] Print
Author Topic: 2.2 dCI (2002) - general question about performance  (Read 13500 times)
Anders Dinsen
Administrator
YaBB God
*****
Posts: 2823



WWW
« Reply #15 on: July 17, 2008, 07:26:16 pm »

That's very true, Tom. In short, only the problems that the computer can "see" will show up. And mostly, the fault codes only show up when something obvious is wrong, for example a short circuit of a sensor or output.

And the thing about knowing how it works and understanding the system is where it gets very tricky and where you need an engineer more than a mechanic. Fortunately some mechanics have reasonably good intuition to the systems, but  there aren't a lot of them around, I'm afraid.

- Anders
Logged

'82 Murena 2.2 prep 142
'01 Grand Espace 24v
'08 Smart Fortwo 0,8 cdi
ianP
Newbie
*
Posts: 16


« Reply #16 on: July 17, 2008, 09:27:13 pm »

Hi,  this is exactly what's happened at the dealer I've just taken my car back to...  they took it to a garage who plugged it into a computer which reported a fault with the EGR.. so they took it out cleaned it and replaced it (even though I'd done this on the weekend).  They checked again and the error code was gone.  So, apparently the car is fine (as there's no fault codes) - it's a miracle! - but when I asked if anybody had given it a propper  road test,  their response was kind of 'why would we bother...  the computer says it's fine so what's the point?'..  yes..  but is it running properly now?  well, we assume so,  all we can do is clear the fault codes - what elso do you want us to do???...  Roll Eyes

What happened to good old fashioned mechanics?  I've been programming computers for 20 years,  I know their not perfect, i've built some terrible software in the past mysenf (some good stuff also obviously)...  these codes are probably nothing more that a pointer to a problem giving a mechanic a 'general idea' about what sorts of systems are playing up.  If ECU's are like any other computer program in the world - if it doesn't know what's wrong, you can bet bottom dollar that the programmer has build in a catch all error somewhere that will have you running
around for days trying to sort out a fault that just doesn't exist!  I know these Diesels are quite advanced now - but they're still internal combustion engines (aren't they?)... that surely that makes  these issues more of an engineering problem than a 'techy's' problem...  are you saying that a 'traditional' mechanic with years and years of experience fixing 'normal' cars doesn't stand a change of sorting these issues out?

(sorry for the rant...  I'm a bit angry at the moment as cars still off the road)...   any time now though she'll be good as new  Grin (fingers crossed).

All the best,
Ian 

Logged

Ian Powell

2002 Renault Grand Espace 2.2dci "the Race"

2004 mini cooper
Anders Dinsen
Administrator
YaBB God
*****
Posts: 2823



WWW
« Reply #17 on: July 18, 2008, 06:46:01 am »

Hi,  this is exactly what's happened at the dealer I've just taken my car back to...

I'm really sorry to hear that... you have perfect reason to rant about the incompetence.

Quote
these codes are probably nothing more that a pointer to a problem giving a mechanic a 'general idea' about what sorts of systems are playing up.

Indeed.

Quote
but they're still internal combustion engines (aren't they?)...

That's what we want them to be... Grin

Quote
that surely that makes  these issues more of an engineering problem than a 'techy's' problem...  are you saying that a 'traditional' mechanic with years and years of experience fixing 'normal' cars doesn't stand a change of sorting these issues out?

I think there are experienced mechanics out there that can fix these problems because the don't trust the computer or because they actually read what the computer says. My petrol Espace suffered from some bad running some months ago, but the computer showed no fault codes at all. The problem turned out to be the ignition coils, which were rusty and gave a bad spark. The computer just advanced the ignition as much as it could, but obviously coulnd't see what kind of spark that took place in the cylinder. It also couldn't "feel" the jerkyness. I bought a new set of coils for it because I know it's a common problem with these engines, not because I *knew* it would fix the problem. Fortunately, it did, and she's running like a new car now Cheesy

- Anders
Logged

'82 Murena 2.2 prep 142
'01 Grand Espace 24v
'08 Smart Fortwo 0,8 cdi
roy4matra
YaBB God
*****
Posts: 873



« Reply #18 on: October 12, 2008, 03:48:22 pm »

Hi,  this is exactly what's happened at the dealer I've just taken my car back to...  they took it to a garage who plugged it into a computer which reported a fault with the EGR.. so they took it out cleaned it and replaced it (even though I'd done this on the weekend).  They checked again and the error code was gone.  So, apparently the car is fine (as there's no fault codes) - it's a miracle! - but when I asked if anybody had given it a propper  road test,  their response was kind of 'why would we bother...  the computer says it's fine so what's the point?'..  yes..  but is it running properly now?  well, we assume so,  all we can do is clear the fault codes - what elso do you want us to do???...  Roll Eyes

What happened to good old fashioned mechanics?  I've been programming computers for 20 years...

Those two last statements show that you Ian (like most unfortunately) don't understand the motor trade and why it has got into the mess it has.  I have been in this trade for over 36 years and have seen the huge changes and development over those years and the problems caused, from the inside, and share your concerns but you cannot entirely blame the garage employees.

You say 'what happened to good old fashioned mechanics?'  Well the first thing you need to understand is that 'mechanics' can only understand mechanical things, which they can see and generally work out what it should do, and what has happened to stop it working.  Their intelligence level is not as great as yours (since you are into programming) and they cannot understand electrics let alone electronics.  This is a historical problem relating to the fact that most mechanics were taken from the low end of the educational system - many were academic failures.  This is still happening today.

Anyone who can do both electrics and mechanics well, has to have a higher level of understanding and is usually known as a technician not a mechanic.  This is an important distinction and it is no good simply giving a mechanic the technician title - he has to be skilled to a high level.  Too many garages abuse the term.  Mechanics think of electrics as a black art and electronics as black boxes of which they have no comprehension at all.  I have seen mechanics make elementary mistakes with very basic electrics and cause wiring burn-outs simply because they don't understand what they are doing.

Now it is difficult enough to separate the ignition system from the mechanical functions of an old engine to decide where the fault lies with an engine that won't start or run properly, but it is impossible to separate the electronics and mechanics on a modern engine when trying to find out why things are not right.  A mechanic just has no chance here.  It has to be a competent technician at least with the right tools to be able, first to understand it, and then work out what has gone wrong.  You have to sort out cause from effect, and even mechanics often get that wrong.  They repair the effect but not the cause, so it happens again.

Manufacturers have zoomed ahead with complex solutions to complex emission legislation using highly skilled and paid engineers without considering the educational standards and skill levels of the service personnel.  Consequently you have the situation now where we have vehicles with complexities beyond all but a handful of the best technicians, who are often hampered by the fact that they won't even give us technicians the information which we want, and the trade is unwilling to pay the levels to get the people they really need.  If you compare the skills required by technicians today, and those in the computer industry, we often have to know more since we have to understand the basic mechanics as well as the electronics, yet we are paid far lower.  The trade may charge a lot, but what does the actual technician get - I can tell you that here in London, the dealers often charge over £100 per hour but the technician rarely gets £12 per hour.  A computer industry technician gets far more.  When you consider this you can see why the person who you need to be a technician is going to get a job in the computer industry where he will get a better salary, whilst working conditions are much better and he doesn't even have to pay for much tooling.  A computer technician can often carry all his tools in a brief case.  A mechanic or technician has a huge set of tool boxes full of tools which can easily cost him £10,000-£20,000.

Renault and other manufacturers answer to this problem is not to pay a decent salary to get the technicians they need.  It is to produce diagnostics systems that you can plug in and should lead the unskilled, step by step to the fault and the cure.  Well I'm sorry but I know that will never work satisfactorily.  In the meantime because of the poor software and understanding, the owners of the vehicles are the ones that suffer.

Quote
... I know these Diesels are quite advanced now - but they're still internal combustion engines (aren't they?)... that surely that makes these issues more of an engineering problem than a 'techy's' problem...

... and that shows how little you (or anyone that thinks the same) really understand the problems we now face in the industry.  I'm not getting at you Ian, it is just that without really understanding the modern engine or vehicle and seeing the changes that have happened with technology, you cannot understand the problems.

To give you just one simple example, there are not many people who really understand what the vacuum advance system does on an old petrol engine distributor.  The 'how' and 'why' of the system.  I have even heard quite skilled mechanics get it totally wrong.  So if they can get something as simple as this wrong, what are they to make of the latest complex engine systems?  For a complex example take this - An automatic is not changing gear properly yet the gearbox computer shows everything is fine in the workshop when hooked up to the diagnostics machine, and there are no errors in any computer.  The problem was with the CAN link between the ABS computer and the injection computer, but both the ABS and injection system worked fine.  Now tell me why?

Quote
(sorry for the rant...  I'm a bit angry at the moment as cars still off the road)...

I'm just as sorry for my rant, but it needed pointing out.  Because I see much of this from both inside the motor trade from bosses who haven't a clue, and the qualification standards are too low; and the outside where the general public gets a raw deal but does not know what is really happening and why.

And it is not likely to change soon either.  My solution was to start working for myself.  Then I can charge a decent rate for my work and skills and have satisfied customers, who are not ripped off by the trade.

Roy
« Last Edit: October 12, 2008, 08:35:27 pm by roy4matra » Logged

Martin Tyas
Sr. Member
****
Posts: 271


Espace, because it's worth it!


« Reply #19 on: October 13, 2008, 01:11:41 pm »

If you compare the skills required by technicians today, and those in the computer industry, we often have to know more since we have to understand the basic mechanics as well as the electronics, yet we are paid far lower.  The trade may charge a lot, but what does the actual technician get - I can tell you that here in London, the dealers often charge over £100 per hour but the technician rarely gets £12 per hour.

If you think that the motor trade is bad Roy you should try the Agricultural or Construction equipment markets.
The going rate is more like £9.00 an hour and the dealers are lucky if they can charge much more than £45 per hour and yet the machines have all the complexities of modern cars in terms of engines, management systems and electronics PLUS complex hydraulic systems and computer controlled electro-hydraulic systems & transmisions. Add to that the fact that they are dealing with machines on which a single wheel & tyre can weigh more than a Murena and an axle more than a fully loaded Espace and must-have service tools are a fortune (as an example the tooling required just to service the brakes of a wheeled loading shovel are £1800). Then realise that 9 times out of 10 they are carrying out repairs in the mud, rain and cold and not in a workshop.
When I was in that game we used to wonder how we could attract service personnel to work in such an environment when they could earn 25% more in the relative comfort of a workshop within the motor trade. So if you think that the car trade has it's problems don't go into either Agriculture or Construction equipment because the hassles were enough for the owner of a company where I used to work for him to take the rather drastic decision to ventilate his own head using a shotgun.

Martin
« Last Edit: October 13, 2008, 02:27:12 pm by Martin Tyas » Logged

1968 Cessna 182L Skylane
1991 BMW 520i SE Auto
2002 Grand Espace 2.2dCi "The Race"
2003 Astra 1.8i Cabriolet "Edition 100"
2011 Insignia SRi VX-Line Red
2011 Honda VT1300CX Fury
MarkJHarris
Newbie
*
Posts: 5


« Reply #20 on: November 10, 2008, 06:54:30 pm »

Hi all.

My name is Mark Harris and I've just registered on this site. I have a 2006 2.2Dci Espace, with only 22,000 miles on it and so went looking for EGR stuff online and arrived here.

I tend to do my own work on cars, and despite being a Pilot by trade, am well read on car mechanics, as well as my passion of motorbikes. Unfortunately, our local Renault dealer is staffed by cynical types so is not easy to deal with, and our car is still under the curse of it's manufacturer's warranty. only april till I can get the tools out!

Roy, I fully understand your dismay. I really do. I spent a few hours trying to treach the local Vauxhall Technicians how a thermostat worked, because they didn't have a clue as it didn't generate a fault code! Enough said.

Ian. The EGR valve on a 2.2DCi Espace Mk4 or 5 should be a solenoid electronic one. This should be shut when de-energised, and the two chambers withing the body will be sealed off from each other. If yours was open, then it was sticking and that's not good. The Turbo was pumping air out of both valves and thus your engine was probably getting no more than atmospheric pressure, yet the airflow meter and any air pressure sensor would detect all was normal and allow the ECU to give full fuel as per revs and your foot pedal position. Result./...no power and loads of soot.

As Roy will no doubt agree, the fundementals are oft forgotten. A Diesel is not like a petrol engine. It does not rely on a correct air/fuel ratio to produce combustion, thus correctly ratioed air/fuel is not premixed and fed to the engine via a throttle to restrict airflow to adjust power made.

A Diesel always gets a full lung-ful and does not have that throttle butterfly. The power depends on fuel supplied...up to the point where it gets too much and then the excess will come out as soot.

Old simple diesels demonstrated it well. You could leave a cloud of black soot behind you and by lifting the pedal slightly, stop the soot cloud without any reduction in power.

Modern engines are covered in electronic valves, pumps and clever stuff, but at the heart of it, if the engine is fed too much fuel for the air it breathes, it will generate soot. Simple as that. Stopping it is less simple.

Why does our Espace fill the EGR with soot? Too much fuel. (You can see this by the fuel consumption- mine's giving 15.2mpg around town Angry) But the Fuel is metered according to an ECU based on Airflow, Absolute pressure, revs and pedal position. So if the fuel is right, the obvious is NOT ENOUGH AIR! Again, this is a fundemental truth, and often not covered by a fault code.

Either; dirty air filter, knackered turbo, sooted up or sticking EGR or leaking hoses or inlet plenum.

None of these will generate a fault code, because they don't involve a closed loop electronic part.

A spinning but underspeed turbo is not going to last long. It'll make a noise and be pretty obvious. Leeking hoses won't happen unless a dodgy mechanic has been playing, and the hiss when you get Mrs to push the loud pedal while you stand at the front should make that obvious too.

The Air filter is bloody hard to get at, but Renault reckon they last 20,000 miles. Hmm.

The EGR is the most likely culprit then. It should be closed or open. Closed when de-powered.

Mine? Well it's under warranty and the Dealer said it was sticking but fine when cleaned.

Note: I'd removed it and cleaned it myself last week. It moved freely, but the outer of the two valves was about 1/2mm off it's seat when the inner one was fully seated. I know it was seated, because petrol wouldn't flow through it. They're on the same shaft so clearly the outer one is out of adjustment. Which is why I booked it in.

The Dealer Foreman doesn't want to speak to me as he thinks I'm full'o'shite as I keep asking questions he can't answer. He reckons it's fine. it must be as it doesn't generate a fault code..... Undecided

Ian, sorry for hyjacking your thread for a moment, but we appear to share at least the same model car, and my fresh experience sounds relevant enough.

What I don't know, is where the air goes that comes out of the end valve in the EGR. anyone?

 
Logged
Matra_Hans
YaBB God
*****
Posts: 642


Owner of Bagheera, Rancho, Murena & Espace


« Reply #21 on: November 10, 2008, 10:25:47 pm »

Hi
I can only say that my newly purchased Espace 2.2 dT 113 HP from 1998 which has done 215,000 km drives like a dream.
It feels powerful, it is very quiet comfortable and fast. I am already sorry that the Espace is going to be my wife's car.
My wife already loves the Espace. When she has been driving the Espace on her own she have actually taken a longer rout then necessary just to enjoy the car, and she is already planning next years summer vacation in the Espace to the south of France with some friends in the Espace.
Good for me that the wife is happy with my choice of car for her!!

Hans


Logged
roy4matra
YaBB God
*****
Posts: 873



« Reply #22 on: November 12, 2008, 07:51:14 pm »

Hi all.

My name is Mark Harris and I've just registered on this site. I have a 2006 2.2Dci Espace, with only 22,000 miles on it and so went looking for EGR stuff online and arrived here.

As Roy will no doubt agree, the fundementals are oft forgotten. A Diesel is not like a petrol engine. It does not rely on a correct air/fuel ratio to produce combustion, thus correctly ratioed air/fuel is not premixed and fed to the engine via a throttle to restrict airflow to adjust power made.

A Diesel always gets a full lung-ful and does not have that throttle butterfly...

Hello Mark,

Yes I agree with almost all you've said.  However, be aware that some modern diesels (including Renault) do now have a throttle plate so the old idea that they can take in as much air as they want no longer applies.  And the common rail diesels have so many differences that you have to very careful not to assume anything, because you can easily be misled, or injured or damage the engine or components, if you do certain things, which would not have been a problem with the old type.

Quote
What I don't know, is where the air goes that comes out of the end valve in the EGR. anyone?

If you mean where does the exhaust gas go, it is fed back into the engine in small quantities to reduce certain pollution by effectively stopping the cylinders filling with fresh air and fuel!

Roy
Logged

MarkJHarris
Newbie
*
Posts: 5


« Reply #23 on: November 15, 2008, 08:44:28 pm »

Thanks Roy. no, what I wanted to know was this;

When you look at the EGR valve, it's obvious the exhaust "feed" is the one nearest the solenoid body, from the amount of soot. When the solenoid operates, exhaust gas is drawn into the other chamber via the valve and sucked into theengine thereafter. However, the outer end of the EGR has another valve on the end, presumably to vent boost pressure or something? Having not seen the body the ER sits in properly, I don't know where air would go if, as on my EGR valve, that outer valve head is mis-adjusted and sits slightly open, even when the inner is closed.

It appears on my car, that the outer one stays slightly open, and I'm wondering if some boost pressure is being lost overboard somewhere? If so, it would explain my fuel consumption woes.....Of course, if that outser valve is just a pressure balancer, and the air that comes out just goes round in the body and onto the engine, then, I'm on a dead end. However, I just don't know that one.

Help.
Logged
colin4255
Sr. Member
****
Posts: 119



« Reply #24 on: August 01, 2009, 01:00:18 am »

i know this is an old post, but you could have actually made the EGR valve problem worse by the way you cleaned it. it sounds like you were far, far to harsh in the cleaning method.   Use only solvent cleaners like carbon cleaner or brake cleaner and a soft brush. Problem with the EGR vale seats is that they have to seal 100% to work effectively and you have effectively been sanding them down and scoring them by using wire wool etc. I know this to my cost.  I'll bet if you bought a new egr valve and fitted it, the issue would go away. One small piece of carbon, that you could hardly see would be enough to jam an egr valve seat open just enough to destroy an engines power in the way you have explained in your initial post, but please, when cleaning them, be patient and be careful - do not use anything that can mark or score the valves or the valve seats in the egr valve, or you'll get the same result from a cleaned valve as from a dirty one.
Logged
Pages: 1 [2] Print 
« previous next »
Jump to: