Peugeot 406 2.0 HDI 90HP, cold start problem

[AndreiNCS]

That's a good idea.

You could well have a tiny leak at the fuel filter, (can be too small for fuel to leak out, but air still gets in).
It's also worth checking the strainer, (filter), in the fuel tank is not blocked, this can give similar problems.

Hi, Doggy

Thanks for the informations. I will come back next week with news, after replacing the whole tank circuit with a bottle with diesel.

Regards

Hi,

As an update, the car starts in the same old way even with this change, so I guess it's not an air leak issue.

Now that the temperature had raise to almost 30 C degrees by day and 15 by night, it starts easier but not at the first second, and still blows some smoke in the first 30 seconds after starting.

[frog]

...and it blows a lot of white / slighthly blue smoke.

and

... and still blows some smoke in the first 30 seconds after starting.

Makes me think of an oil leak into the cylinders...

Valve guide seals maybe?

[AndreiNCS]

Hi, Frog

Could this be also the problem for the hard enginge start, beside the blown smoke?

Thank you very much for your sugestions!

[frog]

I admire your persistance! You will certainly find and fix the problem!

I summarize (copy-paste) what you said earlier, please correct me if i'm wrong:

Symptoms:

• Bad cold start: car starts only after 2-3 keys
• At cold start: blows a lot of white / slighthly blue smoke
• After start, 1 minute of engine working weird (RPM have small deviations, between 700 to 1000 RPM, but after that, it will be constant at 800).
• A lot of white/slightly grey smoke, all these until the engine temperature starts rising. After this, it runs perfectly, and it blows only a little trace of smoke wich I guess it's normal
• After 3-5 hours engine off, depending of how cold it's outside, again the same problem
• Even now when on the day are 20+ and on the night 10+ celsius degrees, it still needs 3-4 engine spins to turn on...

Observations:

• Engine cranks fast
• As long as the engine it's hot, it will start with no problems
• In the summer, the car starts perfectly
• If you unplug the coolant temp sensor jack from the engine, then the car starts way better
• Battery is good
• Compresion test was done twice, in different services and it's on parameters, no value to worry about
• Tried the ingnition on/off trick multiple times, but no effect... I verified if current reach to the glow plugs, if the relay works, and everything works properly. Glow plugs are working fine.
• The electric circuit was checked by 3 different persons, and it seems that is all good
• Last week a different ECU was checked (with all including reprograming and syncronizing) and still the same struggle on starting
• Replaced the whole tank circuit with a bottle with diesel --> the car starts in the same old way even with this change, so I guess it's not an air leak issue
• Tested 2 injection pumps (5WS40018) , and the car shows no difference, it starts in that same hard way

What you already replaced:

• Glow plugs relay
• Glow plugs
• Fuel injection pump
• Coolant temperature sensor
• 3 injectors from second hand
• ECU

My personal rule is: don't fix what is not broken . So first start with a proper diagnosis. A proper diagnosis requires good observation, and "smart but simple" experiments to verify (like you did with the tank circuit and by disconnecting the CTS ). Take into account that there may be more than one issue playing up.

My questions for you at this point:

• If the engine is warm and starts directly, does it still blow white / slighthly blue / grey smoke? You already said: "a lot of white/slightly grey smoke, all these until the engine temperature starts rising. After this, it runs perfectly, and it blows only a little trace of smoke wich I guess it's normal." Is the "little trace of smoke" still white/slightly grey? A hot HDI engine running idle should not give any (visible) smoke al all. Only when you are driving at constant speed then suddenly ask full power, then you might get a bit of soot (black smoke), everything else is not normal.
• "Cylinder head will be removed the see if the head gasket it's broken or any other parts are broken inside the engine... it's my last try" --> did you have this done?
• You say: "After start, 1 minute of engine working weird (RPM have small deviations, between 700 to 1000 RPM, but after that, it will be constant at 800)." Is the engine shaking or running very rough when this happens? That might point to a cylinder not working correctly. The engine may be running on 3 cylinders. I'm asking, because if there is an oil leak along the valve stems, it will probably not be on all 4 cylinders at the same time. If there is such an oil leak, it will start with 1 valve, maybe 2, so that means that 1 or maybe 2 cylinders are not working optimally during the time that the (cold, unburnt) oil is still in the ignition chamber.
• Does this article describe your sypmtoms? Note that this article is for petrol engines, so "high levels of vacuum" does not apply; diesel engines do not have vacuum.

[AndreiNCS]

Hi, Frog

Once again, thank you very much for your time and your attention regarding my issue.

https://www.youtube.com/watch?v=zr66op47OL0

Here it is a video with a start after a night...by the night were aroung 5'C degrees by that time. On this video you can notice the followings:

- engine cranks fast enough
- it needed 2 hard key spins ( and that was a good-ish start... at -10 C degrees it was needed 3 or 4 key spins to start and if I slightly press the acceleration, the engine tend to die. Once at -20 degrees, it really died).
- the colour of the smoke. I've just talked with an mechanic and he said that is unburned diesel. If it was oil in the burn chamber, would have been
blue smoke, but not white-grey.
- the small RPM deviations at the begin... you can even hear that the engine runs not that smooth after what is starts in the first minutes by winter, and seconds by sprind .

Sadly, cylinder head wasn't removed becuase of the money needed and also because no one know certainly what could it be, so for my wallet is not that nice to pay out around 200£ on a guess. I alreay spend enough on others guesses.

Now that the temperature has raised it's starts at the first key, with 2-3 engine spins, around 20 seconds of smoke, and an nonlinear accelaration in the first one minute of runing.

Few more remarks: I always used Total 5W40, and at 10.000km, around 1 liter is "eat", I always have in trunk one liter and do the level after 1-2000 km.

At the replacing parts, yes , these are all:
Glow plugs relay
Glow plugs
Fuel injection pump - also from second hand, i bought it from UK a friend brought it to me from there because it was cheaper
Coolant temperature sensor
3 injectors from second hand
ECU

Another issue that came up, is that the oil temp on the hot days, it's around 130'C degrees at 110km/h. I don't want to know where could it go at 140km/h on 35'C degrees days in June/July. - could it be the oil temp sensor broken? I mention that the coolant it's always 90'C..

Due to my bad English, I don't know if I explained all correctly, but I think that video summarize a good part of the problem.

Once again, thank you very much for your support.

[frog]

You're welcome

If your mechanic is right and the smoke is unburnt diesel, then http://www.dieselsmoke.com.au/ might give an answer:

"White smoke occurs when raw diesel comes through the exhaust completely intact and unburned. [...]
When white smoke occurs at cold start, and then disappears as the engine warms up, the most common causes are fouling deposits around piston rings and/or cylinder glazing."

I must say i have no experience with this.

Maybe you can try first to replace the valve stem seals, they seem to be not so expensive.

You may want to have a look with an endoscope camera into the cylinders, entering e.g. via the glow plug hole or the injector hole.

If all of that does not help i would save some money so you can spend around 200£ to have the cylinder head removed for diagnosis of cylinders and valves... I really think the problem is mechanical here.

Another issue that came up, is that the oil temp on the hot days, it's around 130'C degrees at 110km/h. I don't want to know where could it go at 140km/h on 35'C degrees days in June/July. - could it be the oil temp sensor broken? I mention that the coolant it's always 90'C..

I would not worry about that too much now. Oil temp of 130'C is pretty ok, a little bit high but ok. First solve the smoking and bad starting

[AndreiNCS]

I guess, removing the cylinder head would give me some definitely aswers, and by that I refer to the valve stem seals, head gasket and so on...
By then, I think I will buy an endoscope camera to do what you said.

Is it possible to replace to valve steam seals without removing the cylinder head?

[frog]

Is it possible to replace to valve steam seals without removing the cylinder head?

I never did it myself but it seems to be accessible by lifting the rocker cover. So no cylinder head removal necessary.

Here is the diagram from "Service box".

Valve stem seal.jpg

I found the seals for sale on Internet part shops for as little as € 1,34 a piece (Google for part number "095648"). For that kind of money you can always try...

[frog]

Not sure if it is an easy job, even if you don't have to remove the cylinder head. You may need some special tools.

Some details on https://frenchcarforum.co.uk/forum/view ... hp?t=19808 . At the very least, take good care that you not drop the valve into the cylinder!

See it as a "challenge"

[AndreiNCS]

Once again, thank you very, very much for these valuable informations.
I will definitely investigate on this path ...

I will come back in a few days with updates.

I'm working at 200 miles away now and I get the chance to see the car only by the weekend.

[AndreiNCS]

Hi guys

After a walk to the mechanic, he said that certainly it is not the steam valve seals.

Here: https://www.youtube.com/watch?v=Yz_fTT4Tagw
I uploaded a video with a start at 20+ C degrees, and even in the night there was above 15 C degrees.

You can notice the smoke after starting, and if you're listen carefuly, you can hear the jerky accelarations ... it will accelerate smooth, as it suppose to do, after 1 minute of engine running, and I forgot to film it, but it also blows a lot of smoke when pressing the acceleration in that first minute of running.

Thanks in advance for your suggestions!

[jasper5]

I think you may have an injector problem here, however, by the looks of things and given the mileage (high Kilometers covered) I think you should be realistic and see that this problem may be one of a tired engine.

I agree with your mechanic...the smoke looks like unburnt diesel.

[AndreiNCS]

I think you may have an injector problem here, however, by the looks of things and given the mileage (high Kilometers covered) I think you should be realistic and see that this problem may be one of a tired engine.

I agree with your mechanic...the smoke looks like unburnt diesel.

Sadly, it's not an injector problem. I have tested them, and 3 of them were broken, so I replaced them and also the HP Pump.

And about the covered kilometers, I saw cars with 500.000km and running perfect. It is only a problem with the start, after that, the engine runns perfectly.

[frog]

I'm out of idea's, i'm sorry

[AndreiNCS]

I'm out of idea's, i'm sorry

Any idea if this could be related with the rampe injection? Or the sensor on it, for backflow?