Good egr voltages

[Tdci-Peter]

1 hour ago, yankee_1983 said:

I have tested it as following:

- the resistance between pins 2&3 is ~3.7Ohms. 

- when connected them to GND and 12V (directly to the motor after dismantling the head and the valve) nothing happens, just sparks. 

That sounds a bit like the motor armature is jammed, or the commutator is so worn or covered in carbon as to be a near short circuit. Can the motor armature be turned easily by hand?

If it does move, try energising it the other way round. I think +12v should be pin 3 and Gnd is pin2, but that is just from a little + symbol on the drawing, so is not quite 100% certain.

EGR valves are usually mounted in a place where they can get rather hot, and also get a lot of vibration from being solidly mounted to the engine. The design of many of them is just not up to the job. Other problems might be that if the seals in the valve were weak, soot from the exhaust (they are before the DPF), or oil from the intake air can get in. oil and motor commutators do not go together at all well. The gas pressure at the valve end ramps up and down with the turbo, so can force soot or oil up into the motor.

[yankee_1983]

 

12 hours ago, Tdci-Peter said:

That sounds a bit like the motor armature is jammed, or the commutator is so worn or covered in carbon as to be a near short circuit.

I think this can be the cause. I found soot in the valve housing. But how can be tested electrically that is a short circuit? As I think, it is expected for the current to be higher than normal, but, which is the current for the normal operation? I have already replaced the EGR valve so it is a little difficult to check the current on the engine.

12 hours ago, Tdci-Peter said:

Can the motor armature be turned easily by hand?

After dismantling of the head housing the axle of the rotor could be turned easily.

12 hours ago, Tdci-Peter said:

If it does move, try energising it the other way round. I think +12v should be pin 3 and Gnd is pin2, but that is just from a little + symbol on the drawing, so is not quite 100% certain.

As I said earlier, I have already tried it, and by reversing the the polarities for short time. or, what exactly do you mean by energising?

I don't understand why some guys told above that one pin is connected to F35, but, according to the scheme both pins 2&3 are connected to the ECM module as following (1.6TDCi engine):

OR, other year, but it's the same construction regarding EGR:

12 hours ago, Tdci-Peter said:

Other problems might be that if the seals in the valve were weak, soot from the exhaust (they are before the DPF), or oil from the intake air can get in. Oil and motor commutators do not go together at all well. The gas pressure at the valve end ramps up and down with the turbo, so can force soot or oil up into the motor.

One mention: my engine don't have DPF(it 90PS model, 2007). Regarding oil, I confirm that there is some oil at the intake air (it is consumed around 2/3 of oil dipstick in 10,000km/6,000miles), but that oil becomes soot, so no oil comes to valve module. 

I want to check everything is possible for testing, and after that I'll dismantle by braking it(I don;t think it can dismantle other way) as to check what's happening inside.

Thank you for the unswer.

[Tdci-Peter]

7 hours ago, yankee_1983 said:

But how can be tested electrically that is a short circuit? As I think, it is expected for the current to be higher than normal, but, which is the current for the normal operation?

Testing an electric motor is a bit tricky. The reading of 3.7 ohms with the rotor stationary sounds reasonable, maybe a little high even. But meter connections etc will have an effect.

The current drawn when powered up will vary enormously depending how much work it is doing, A free running motor of that size spinning with no applied torque, may draw under 100mA. But slow down the rotor by some means, and the current will ramp up rapidly, to several amps.

With the valve in situ, all you can do is re-check the resistance at various times, and maybe tap the valve unit, to see if it varies. Bad commutators and other bad connections usually give variable readings.

By energising, yes, I meant applying voltage.

[yankee_1983]

3 hours ago, Tdci-Peter said:

Bad commutators and other bad connections usually give variable readings.

As I remember when spinning the rotor slowly the resistance didn't vary too much, around 3.6~3.8, but when rapid spinning it was a little grater 3.6~4.2 ohm. I'll recheck it at different angles, and also the current. 

[Tdci-Peter]

12 minutes ago, yankee_1983 said:

As I remember when spinning the rotor slowly the resistance didn't vary too much, around 3.6~3.8, but when rapid spinning it was a little grater 3.6~4.2 ohm.

When I have tried moving the rotor of a motor while measuring its resistance, the reading jumps about all over the place, sometimes high, sometimes even reading negative! This is due to the back EMF from any permanent magnet motor, it really upsets most multimeters on ohms range. It should quickly settle to a fairly consistent, low value when the movement stops.

If you are not getting back EMF, then either the motor is not a permanent magnet sort (EGR motors usually are permanent magnet), or there is a more basic problem like a shorted armature. Combined with a bit of poor contact from dirty or worn brushes or commutator, that could be the cause of the failure.

 

[yankee_1983]

9 hours ago, yankee_1983 said:

As I remember when spinning the rotor slowly the resistance didn't vary too much, around 3.6~3.8, but when rapid spinning it was a little grater 3.6~4.2 ohm.

One correction, maybe I didn't spin rapidly. After recheck, also energizing, the following are the results:

- resistance checking: spinning slowly -> 3.4-4.1 Ohms; spinning rapidly -> 2.5-4.9 Ohms.
- current checking when applying voltage: constantly 2.84x A (only x = 4~8 aprox), and no sound
- when spinning the rotor on the ear with the whole rotation(without any voltage), there is a small sound like a wire is touching the housing.

I think the verdict is: UNUSABLE, when I have time and if I can break it I'll show here what's inside..

THank you for the support.

[yankee_1983]

I dismantled the motor and found that the soot can be excluded from the list of causes, because there weren't any soot. 

I think the main cause is the quality of the materials for producing these motors. 

[ojan]

i know it is an old post but i would like to mention that pins 3 and 4 will not give 12v unless the engine is running (ignition on is not enough). sometime, regular cleanning of EGR (once a year) goes a long way. This video shows how to do the cleaning tdci, di turbo(Y6), hdi, ( ford, mazda, volvo, peugeot, citroen)