Blue smoke, rough idle - Forscan DTC code

[Albert27]

Hi all,

Some of you may remember from my previous thread in November that for the past year I've had blue smoke on cold starts and rough idle for 20 seconds then everything is fine.  One of you suggested running Forscan to see if that throws anything up.  Finally got round to setting it up with a smartphone app and it's thrown up a code:

 

P1402-21 Exhaust Gas Recirculation Metering Orifice Restricted *what a mouthful* ( the latter bit didn't appear on forscan!)

-Status Previously set DTC- not present at time of request.

- Malfunction indicator lamp is off for this DTC

Module : Powertrain control module

This stuff is all new to me so would be grateful if you more knowledgeable guys could throw some light on this for me and whether or not this code is connected with my original symptoms.  It's a 1.6tdci 2008.  Thanks in advance!

[alexp999]

Sounds like EGR valve needs a clean.

[Albert27]

7 hours ago, alexp999 said:

Sounds like EGR valve needs a clean.

Thanks Alex.  What does cleaning it involve?  Is it a job someone like myself with only basic knowledge could do without too much difficulty?

[Tdci-Peter]

On 27/01/2017 at 2:10 PM, Albert27 said:

throw some light on this for me and whether or not this code is connected with my original symptoms.

I find it hard to link smoke & rough idle on cold starts with a restricted EGR valve. I would link those symptoms with a jammed open EGR, or, if it is temperature dependent, with glowplugs. A closed or restricted EGR  should reduce smoke rather than increase it. But the code could be a bit misleading, maybe a sticking valve could cause it if it is jammed part open.

I have been having some very rough starts when the temperature is below about 5C. It fires up ok, but then sounds like it is running on two cylinders, with clouds of smoke, for about 30sec. Once warmed up it is fine. I have found one glowplug to be non-working (high resistance), and replaced it, but have not had a cold enough start to test it yet. And I have yet to test two of the plugs, rain stopped play on Friday!

I have not seen a 1.6TDCI EGR valve myself. It is relatively easy to remove off the 1.6. The plastic trim under the wipers should come off (remove wipers by pulling the ratchet handle towards the wiper arm, avoiding putting force on the wiper drive mechanism. The clips along the front of the plastic cover are a pig, I flattened out the spikes on one side of all of them so they are still secure but much easier to remove now.)

Then the EGR is just held on by two bolts, the book says. I am not sure how easy it is to move the valve mechanism, I would use a variable power supply to drive the motor in it, to verify it works. A 12v battery charger could probably also be used as a crude test. The pin-out of the EGR is below. The motor pins should have a low resistance (under 10ohm, I guess), and the pot pins probably in the region of 1000 to 10,000 ohms end to end On my car, I have had at least 3 electrical connection problems inside the EGR, the valve itself seems fine. Just as well, on the 1.8 the valve is a massive job to remove, but the actuator is easy to get off.

For cleaning, remove any obvious build up, but it really needs operating to get it working freely. Alcohol (IPA or meths) can be used as a cleaning agent for oily residues without harming rubber or electrical parts.

[Tdci-Peter]

On 27/01/2017 at 2:10 PM, Albert27 said:

P1402-21 Exhaust Gas Recirculation Metering Orifice Restricted

If you are not planning to take the car to a garage, then it is a good idea to note down the code, any relevant symptoms & the date etc, and clear the DTCs. The frequency at which it re-occurs is part of the diagnostic process. If rare and irregular, it may be an intermittent electrical fault. Or it may re-occur under certain conditions. Either would be an additional clue.

For a non-critical fault like this, which you are intending to investigate yourself, this is the best path.

Also, if the MIL is on, it will not be possible to see if any other errors, perhaps more critical, occur.

After servicing or replacing the EGR valve, it may be necessary to make the car relearn the EGR closed position. Forscan can do this, there should be a "Reset EGR Valve Adaptations"  or similar service procedure in the menu.

[Albert27]

On 29/01/2017 at 10:56 PM, Tdci-Peter said:

If you are not planning to take the car to a garage, then it is a good idea to note down the code, any relevant symptoms & the date etc, and clear the DTCs. The frequency at which it re-occurs is part of the diagnostic process. If rare and irregular, it may be an intermittent electrical fault. Or it may re-occur under certain conditions. Either would be an additional clue.

For a non-critical fault like this, which you are intending to investigate yourself, this is the best path.

Also, if the MIL is on, it will not be possible to see if any other errors, perhaps more critical, occur.

After servicing or replacing the EGR valve, it may be necessary to make the car relearn the EGR closed position. Forscan can do this, there should be a "Reset EGR Valve Adaptations"  or similar service procedure in the menu.

Been out to the car this morning to have another go at using forscan and the original code (P1402-21 EGR) has vanished.  No sign of it.  I didn't reset the code either to my knowledge.  Does this indicate anything?  The only code I have now is a 'U' code relating to power steering and something about a missed message or engine rpm faulty data.

The usual symptoms, blue smoke, rough idle continue...... 

Also I notice on the lite app in the menu there is an option for 'Tables', 'Dashboard', 'Graphs' and a reference to PID's.  Can't get them to do anything and unsure what a PID is?

[GaryPL]

Doesn't tie in with the error code you got, but the symptoms you describe are typical of valve stem seals. This happened on my old diesel Corsa.

Rev it slightly from a cold start and it'd judder and belch a lot of smoke. Then 30 or so seconds later after you moved off or booted it, it was all back to normal.

[Albert27]

4 minutes ago, GaryPL said:

Doesn't tie in with the error code you got, but the symptoms you describe are typical of valve stem seals. This happened on my old diesel Corsa.

Rev it slightly from a cold start and it'd judder and belch a lot of smoke. Then 30 or so seconds later after you moved off or booted it, it was all back to normal.

Do you mean the P EGR code or the U code? How long did you drive your corsa like that?  Mine's been like it for the best part of a year.

[GaryPL]

Am I missing a U code? Can't see one in this thread?

I drove mine like it for quite a while. Basically, what happens is as the engine cools, everything contracts. As the oil is thinner, it seeps past the seal and into the cylinder. Only a tiny amount. But the engine, as it fires over, burns the oil. Hence judder and blue smoke.

Get it checked though as burning oil can be a symptom of far more serious stuff.

[Tdci-Peter]

7 hours ago, Albert27 said:

in the menu there is an option for 'Tables', 'Dashboard', 'Graphs' and a reference to PID's.  Can't get them to do anything and unsure what a PID is?

A PID is a reading or value stored in one of the modules in the car, that can be read by external equipment, like Forscan. There are a lot of these, and they contain lots of useful information. Usually all of the engine sensors can be read, from basics like speed & rpm to fuel rail pressure and fuel injection quantity. They can be very useful aids in tracking down problems. There should be one or two relating to the EGR, eg valve position & maybe demand signal. These reading are in real time, varying as the engine etc varies.

Once you have selected  the data (table/dashboard/graph) option, there should be an symbol, at the bottom of the screen on the laptop version, which is called setup, and will give you a list of available PIDs. You basically move the PIDs you want to monitor into another list on the screen. Then, on going back to table or dashboard, they should appear. Another symbol at the bottom of the screen will now start real-time monitoring. Other buttons are to stop monitoring, to store the results, and to recall previous results. So you can start monitoring, drive, stop the car, stop monitoring, save the results and review at leisure. It is a good system once you have mastered the slightly quirky interface. But then it is Russian!

The smoke could be oil. The term blue smoke usually refers to oil, but the colour difference between diesel smoke and oil smoke is not very obvious, unless perhaps you are an old hand at it. The smell is more noticeable, burnt oil is particularly yukky. Most drivers will have followed a car burning oil at some time. Though it is rather less common now.

Careful monitoring of the oil level is a better indicator. It is best to monitor it some time after a decent run that has heated the engine up fully, and then cooled. And always on the same gradient, ideally flat, but the same location each time on a sloping drive will do. It is an important difference as the causes will be very different.

 

[Albert27]

47 minutes ago, Tdci-Peter said:

A PID is a reading or value stored in one of the modules in the car, that can be read by external equipment, like Forscan. There are a lot of these, and they contain lots of useful information. Usually all of the engine sensors can be read, from basics like speed & rpm to fuel rail pressure and fuel injection quantity. They can be very useful aids in tracking down problems. There should be one or two relating to the EGR, eg valve position & maybe demand signal. These reading are in real time, varying as the engine etc varies.

Once you have selected  the data (table/dashboard/graph) option, there should be an symbol, at the bottom of the screen on the laptop version, which is called setup, and will give you a list of available PIDs. You basically move the PIDs you want to monitor into another list on the screen. Then, on going back to table or dashboard, they should appear. Another symbol at the bottom of the screen will now start real-time monitoring. Other buttons are to stop monitoring, to store the results, and to recall previous results. So you can start monitoring, drive, stop the car, stop monitoring, save the results and review at leisure. It is a good system once you have mastered the slightly quirky interface. But then it is Russian!

The smoke could be oil. The term blue smoke usually refers to oil, but the colour difference between diesel smoke and oil smoke is not very obvious, unless perhaps you are an old hand at it. The smell is more noticeable, burnt oil is particularly yukky. Most drivers will have followed a car burning oil at some time. Though it is rather less common now.

Careful monitoring of the oil level is a better indicator. It is best to monitor it some time after a decent run that has heated the engine up fully, and then cooled. And always on the same gradient, ideally flat, but the same location each time on a sloping drive will do. It is an important difference as the causes will be very different.

 

Thanks Peter.  I think I'm with you on the PID's. Will give it another go and see what i can figure out!  

I'm almost certain that the smell when it occasionally gets wafted in the car with a door open is that of strong Diesel and not burning oil.  The oil level has remained pretty constant since my last change 7000 miles ago; I've not topped up once.  Assuming then that the blue smoke is diesel; are we pointing back towards the EGR valve being the main suspect again?  But does it make any sense that the DTC code has now gone?

[Tdci-Peter]

59 minutes ago, Albert27 said:

pointing back towards the EGR valve being the main suspect again?  But does it make any sense that the DTC code has now gone?

The code you saw was a pending one, it had not lit the EML (according to your 1st post), which is normal for this type of fault, the EML comes on if happens twice in close succession. This is to avoid little one off glitches from worrying drivers or causing Warranty work (from Ford's point of view). As it was a one off, and has now not re-appeared, then the EGR problem may just be an intermittent electrical fault, or even not a real fault. All you can do there is run a diagnostic check from time to time, to see if and when it comes back.

That leaves the smoke & rough idle after start. Assuming it is diesel:

If it is limited to very cold conditions, I would suspect glowplugs first. I am not sure how easy it is to disconnect the plugs on a 1.6, and test them. It is almost impossible to test them when linked together, without a clamp on current probe. But when separate, they can be tested with a multimeter, and should be virtually short circuit (less than 1 ohm), from the terminal to the engine.

EGR remains possible, but is not the prime suspect for me. Fitting a cheap blanking plate would rule out that, even if it did put the EML on (some 1.6s do not like blanking plates). Disconnecting the MAF is another easy test, a variety of bad running problems can be caused by this. Disconnecting it will again put on the EML (with a MAF DTC), but some people have found it cures their problem, as a faulty MAF is worse than no MAF. (Faulty MAF could even cause the EGR error, as the MAF is used by the ECU in determining the EGR flowrate.)

Then it may go into the realms of fuel pumps and injectors, and Forscan can assist in diagnosing problems here, but it is rather difficult.

[Albert27]

On 04/02/2017 at 10:13 PM, Tdci-Peter said:

The code you saw was a pending one, it had not lit the EML (according to your 1st post), which is normal for this type of fault, the EML comes on if happens twice in close succession. This is to avoid little one off glitches from worrying drivers or causing Warranty work (from Ford's point of view). As it was a one off, and has now not re-appeared, then the EGR problem may just be an intermittent electrical fault, or even not a real fault. All you can do there is run a diagnostic check from time to time, to see if and when it comes back.

That leaves the smoke & rough idle after start. Assuming it is diesel:

If it is limited to very cold conditions, I would suspect glowplugs first. I am not sure how easy it is to disconnect the plugs on a 1.6, and test them. It is almost impossible to test them when linked together, without a clamp on current probe. But when separate, they can be tested with a multimeter, and should be virtually short circuit (less than 1 ohm), from the terminal to the engine.

EGR remains possible, but is not the prime suspect for me. Fitting a cheap blanking plate would rule out that, even if it did put the EML on (some 1.6s do not like blanking plates). Disconnecting the MAF is another easy test, a variety of bad running problems can be caused by this. Disconnecting it will again put on the EML (with a MAF DTC), but some people have found it cures their problem, as a faulty MAF is worse than no MAF. (Faulty MAF could even cause the EGR error, as the MAF is used by the ECU in determining the EGR flowrate.)

Then it may go into the realms of fuel pumps and injectors, and Forscan can assist in diagnosing problems here, but it is rather difficult.

I've been rather distracted of late with brakes, discs and a heat shield falling off so my rough idle and blue smoke has gone to the back burner. Have finally had a chance to get out and run one of those PID tests on the EGR while on a short drive.  I picked two from Forscan and I'll post the graph below.  All looks very clever but I have no idea how to interpret the results!  If you could glance your eye over them Peter I'd be grateful.  Worth noting that since the EGR DTC disappeared it has not returned.

With the warmer mornings the car has still been up to its antics so I guess that makes glow plugs less likely.  I'm yet to have a go on the MAF so that's still to do.  I have however been keeping an eye on the oil level and there is no sign of it losing any although I need to check it again after the weekend.  

The MOT is due in May, will the blue smoke issue make it a problem emission wise in the MOT?

[Albert27]

[Tdci-Peter]

If I recall, EGRVP is valve position, which will be signal coming back to the PCM from the EGR, and EGRVR is the duty cycle, which is the drive signal from the PCM to the EGR. Your Forscan system should verify this, there should be an option that displays an explanation of each PID, buried in the system somewhere. I can't remember if it came up when just hovering with the mouse pointer (laptop version), or there was a button at the bottom of the list of PIDs that showed it. (I can't easily get this info, the 1.8 has a different PID list)

That EGRVP trace (red one?) looks dodgy to me. It seems to jump wildly between near zero and near full scale in response to quite small changes in the duty cycle. I would expect a much more proportionate behavior. That suggests that either the valve is sticky, and jumping about, or there is an electrical fault in the pot feedback signal.

I would get that valve out, test it (though that needs a variable 0-12v power supply really, and a DMM), and probably clean it.

These EGRs are just not up to their jobs! I have just had to blank mine off again, as the closed position signal is moving about, and it is starting to affect the driving, by causing little unexpected power dips, again. I have already repaired it 3 times. It has been (different) electrical bad connections inside the actuator each time so far. The combination of heat & vibration at the valve is tough, and the actuator is just not designed to cope. Diesel engines use rapid combustion as one important way to gain efficiency, but this does shake all the stuff bolted to the engine about a bit.

 

 

[Albert27]

17 hours ago, Tdci-Peter said:

If I recall, EGRVP is valve position, which will be signal coming back to the PCM from the EGR, and EGRVR is the duty cycle, which is the drive signal from the PCM to the EGR. Your Forscan system should verify this, there should be an option that displays an explanation of each PID, buried in the system somewhere. I can't remember if it came up when just hovering with the mouse pointer (laptop version), or there was a button at the bottom of the list of PIDs that showed it. (I can't easily get this info, the 1.8 has a different PID list)

That EGRVP trace (red one?) looks dodgy to me. It seems to jump wildly between near zero and near full scale in response to quite small changes in the duty cycle. I would expect a much more proportionate behavior. That suggests that either the valve is sticky, and jumping about, or there is an electrical fault in the pot feedback signal.

I would get that valve out, test it (though that needs a variable 0-12v power supply really, and a DMM), and probably clean it.

These EGRs are just not up to their jobs! I have just had to blank mine off again, as the closed position signal is moving about, and it is starting to affect the driving, by causing little unexpected power dips, again. I have already repaired it 3 times. It has been (different) electrical bad connections inside the actuator each time so far. The combination of heat & vibration at the valve is tough, and the actuator is just not designed to cope. Diesel engines use rapid combustion as one important way to gain efficiency, but this does shake all the stuff bolted to the engine about a bit.

 

 

I have to say I didn't think it looked normal but that was pure guess work on my part and probably it being a red graph made it look sinister  and yes you are right it is the valve position. I will give it a clean in due course. As ever thanks for the helpful info.  Do you think this issue will affect MOT result if not rectified before then?

Also Peter, I intend to clean or disconnect the MAF first as has been suggested.  If I go for the clean, is it good enough to use Halfords Electrical contact cleaner?  It has good reviews.......  If I am to run the car for a bit first with the MAF completely disconnected;  Do I just unscrew the sensor and leave a gap in the pipes?  Or do i remove the section of pipe the MAF is fitted too?  If this is the case do the other pipes stretch to fill the gap?  Hope that makes sense.......

[Tdci-Peter]

11 hours ago, Albert27 said:

If I am to run the car for a bit first with the MAF completely disconnected;  Do I just unscrew the sensor and leave a gap in the pipes?  Or do i remove the section of pipe the MAF is fitted too?

It should be enough to just electrically disconnect it, IE remove the plug. The MAF itself offers very little resistance to the airflow, and is best physically left in place. The ECU will detect it is disconnected, and use other ways to calculate the airflow, form the MAP & rpm & Inlet air temperature. If the MAF was faulty, this will give better results.

For cleaning delicate and electronic parts, I usually use alcohol, either Meths, or Isopropyl Alcohol (IPA). These do nor atack plastics or rubbers, and dry with little or no residue. But I expect contact cleaner is similar, and will do ok.

I think the MoT should be ok. On my car (1.8), the EGR shuts above 2500 rpm, and the MoT smoke test is done at high rpm. So providing the valve is not jamming open (it does not look like it is), then it should be ok.

 

[Albert27]

On 29/01/2017 at 10:56 PM, Tdci-Peter said:

After servicing or replacing the EGR valve, it may be necessary to make the car relearn the EGR closed position. Forscan can do this, there should be a "Reset EGR Valve Adaptations"  or similar service procedure in the menu.

Peter, is there any alternative to resetting the EGR valve with forscan?  For example, would disconnecting the battery achieve the same?  I only ask because I have forscan lite and am unsure if the reset is possible on that.  I've just posted a thread on the forscan forum to see if they can enlighten me on the lite app.

I've disconnected the maf and it's made little difference. So I'm going to have to get the EGR out and go for the clean.  What do you use to clean the EGR? 

[Tdci-Peter]

1 hour ago, Albert27 said:

is there any alternative to resetting the EGR valve with forscan?  For example, would disconnecting the battery achieve the same?

All the info I have heard suggests that a battery disconnect will not do it. Also I do not think the Lite (app) versions can do service functions. I got this from:

http://forscan.org/comparsion.html

(This page may already be out of date, the Forscan team update their programs more quickly than they update their support & documentation pages!)

If the valve is only being cleaned, I doubt if the reset adaptions will be needed. I would worry about that later. There is a complex thread on these valves on this site, I have been attempting to help, with little success () I have to admit. The problem there seems to be getting the relearn service procedure to work. On the 1.6 there are a lot of EGR PIDs, including whether each end of the travel is "learnt", current learnt values, and current position & duty cycle values. So I would not advise any reset unless there was a clear need.

I have not cleaned the inside of one yet. On the 1.8, the mechanical valve part is very hard to access. I have only done the electrical actuator part. But for the mechanical valve (flow path), carb cleaner is one, quite aggressive, cleaner often used. WD40 or meths are possible alternatives. Though most cleaners will only soften the gunk a bit, careful use of a stiff brush or other tools may be needed to remove it. For any electrical parts or connectors, I would used meths, Isopropyl alcohol or contact cleaner.

The EGR thread (Warning: it is a bit technical!) is:

 

[Albert27]

3 minutes ago, Tdci-Peter said:

All the info I have heard suggests that a battery disconnect will not do it. Also I do not think the Lite (app) versions can do service functions. I got this from:

http://forscan.org/comparsion.html

(This page may already be out of date, the Forscan team update their programs more quickly than they update their support & documentation pages!)

If the valve is only being cleaned, I doubt if the reset adaptions will be needed. I would worry about that later. There is a complex thread on these valves on this site, I have been attempting to help, with little success () I have to admit. The problem there seems to be getting the relearn service procedure to work. On the 1.6 there are a lot of EGR PIDs, including whether each end of the travel is "learnt", current learnt values, and current position & duty cycle values. So I would not advise any reset unless there was a clear need.

I have not cleaned the inside of one yet. On the 1.8, the mechanical valve part is very hard to access. I have only done the electrical actuator part. But for the mechanical valve (flow path), carb cleaner is one, quite aggressive, cleaner often used. WD40 or meths are possible alternatives. Though most cleaners will only soften the gunk a bit, careful use of a stiff brush or other tools may be needed to remove it. For any electrical parts or connectors, I would used meths, Isopropyl alcohol or contact cleaner.

The EGR thread (Warning: it is a bit technical!) is:

 

Enough material there to keep me occupied for a few hours!  Thanks Peter.  What is actually being done when 'resetting the valve'?  If i remove the valve and clean it why would it not need resetting?   Is it because I'll put it back in the same position it was removed?  I'm only concerned in case I can't re start the car and get stuck (flash backs of my fuel filter change in December ).

[Tdci-Peter]

9 minutes ago, Albert27 said:

is it because I'll put it back in the same position it was removed?  I'm only concerned in case I can't re start the car

Yes, the position should not have changed since it learnt its positions last.

I have not heard of any EGR faults causing a failure to start. Usually the worst is the EML on, or a little loss of power. The car would still drive ok.

I believe the valve goes though a test on every switch off of the ignition. It can find the open and closed positions here just by driving it to the stops. Normally an error here causes the EML on. After a reset adaptions, when re-learning, it should instead accept the new positions as the learnt ones. But there does seem to be some doubt about that, on at least some versions of this car. I will keep watching the other thread to see if any clues emerge.

(Valves, flow & pressure are my job, or a major part of it. So I do, sadly, get drawn to these sorts of things!)

[Albert27]

2 minutes ago, Tdci-Peter said:

have not heard of any EGR faults causing a failure to start. Usually the worst is the EML on, or a little loss of power. The car would still drive ok.

This has somewhat allayed my paranoia of tampering with it!  

And just finally on the MAF; I've had it unplugged for two days now and the engine light has come on and the MAF fault codes have appeared.  Does it matter how long I leave it unplugged? 

[Tdci-Peter]

51 minutes ago, Albert27 said:

Does it matter how long I leave it unplugged? 

Not if there are no other symptoms like rough running, smoke or excess combustion noise. But do check the DTCs, because with the EML on, you can not tell if something else has happened as well.

[Albert27]

@Tdci-Peter Well, 7 months later and I've finally removed and cleaned the EGR Valve.  It was stiff in its movement and had some carbon deposits.  Cleaned it all up and put it back in.  However, it has made no difference to the blue smoke and rough idle.  Can we completely rule out the EGR now? 

I'm kind of wondering where I go next in terms of narrowing down this fault.  Just as a reminder, I have no DTC codes showing, my only symptoms are Blue smoke on cold starts regardless of outside temperature, rough idle for 15- 30 seconds immediately after & a strong smell of diesel.  It has now been like this the best part of two years although I think the blue smoke is getting worse in terms of the amount it pumping out and the strength of it on a cold start.  

Valve stem seals & injectors have been mentioned but how would I go about narrowing it down as far as possible?  

[Tdci-Peter]

39 minutes ago, Albert27 said:

Valve stem seals & injectors have been mentioned but how would I go about narrowing it down

Valve stem seals will leak engine oil into the combustion chambers, and this can happen while the engine is stopped, with a resulting period of burning oil when started. But burning oil smell is usually very different to diesel, and there would be a gradual loss of engine oil.

I have not heard of an injector fault which only happens when cold. Maybe a small leak inside an injector could be allowing fuel into the engine all the time, and this will continue for a while after switching off, as the fuel rail retains some pressure for quite a time (it does on my 1.8, anyway). If there was a pool of diesel in a cylinder when starting, it would give rough running & smoke until it had all been removed. Though that would not take long. I would say less than 15 seconds.

Maybe another possible is poor compression caused by sticking piston rings, that seal ok once the piston warms up and expands. This would increase the ignition delay, so making the fuel burn later than normal, or not at all, again likely to give rough running & smoke.

If there is no noticeable oil loss, then a cylinder compression test maybe the next easiest test, followed by a leak-off test that can identify some types of injector fault. The leak-off test just measures the fuel returning to the tank from each injector, so is not a major job, but does need some equipment (fittings & pipes, mostly).

What about cool starts, after say an hour? So the engine is just warm, but all the internals like pistons & injectors will be well below their operating temperature? Is there a critical temperature. If so, maybe glowplugs are back in the frame. My car starts fine without waiting for glowplugs down to about 10C, but below about 5C (engine water jacket temperature), it really needs them. The temperatures may be different on the 1.6.