406 1.9TD - the dreaded blue smoke...

[r.welfare]

I've just purchased a 406 L 1.9 turbodiesel saloon, 1997 model year. The car has done 230,000 miles.

Upon collecting the car today, it started fairly easily from stone cold but blew out a fair bit of blue smoke. Driving the car home (15 miles on A and B roads) indicated that the smoke was still present when idling at the end of the journey, and when sat idling at traffic lights. The smoke is definitely noticeable from the nearside rear view mirror but not a complete smokescreen - standing at the back of the car you can see more of it. The idle also felt a little lumpy to me, even at the end of the journey, but the car seemed to pull smoothly enough during the drive itself.

On the move, I didn't notice any smoke other than the soot indicating the turbo was kicking in - although this particular 406 has no revcounter, so I couldn't use my experience of the two 405 1.9TD's I also own as reference to whether it was happening at the "right" engine speed. However I would certainly say this 406 feels much slower than either of my 405s. Browsing through the forum though I understand this is not unusual!

I have not yet had a chance to check the oil level (or indeed whether it consumed any during the trip), or when the car was last serviced (on the latter subject, I would suggest not recently). There were no warning lights on the instrument panel. The one thing I did notice - that may or may not be connected - was that the temperature gauge rose only once over 70 degrees during the whole trip, whilst in traffic.

So I am thinking the thermostat may be stuck open, and that the car is perhaps being overfuelled because it thinks it is cold? I'm hopeful that the head gasket is OK, as I was pleased to note that there was decent heat being produced through the air vents, but haven't checked the rad cap for pressure yet.

I will give the car a full service (oil, and oil/air/fuel filters), drain and replace coolant and change the thermostat as a matter of course, but in the meantime, should I be checking anything else - EGR (new one on me as both my 405's are non-cat 1.9TDs), any particular pipework? Is it easy to get the cambelt covers off so I could do a rough test of belt tension (awaiting a Haynes at this stage!)?

Many thanks
Richard

[CitroJim]

Hi Richard and welcome to the forum

Blue smoke out of a 1.9TD is pretty unusual. Certainly a good service and an oil change is the first move. If there is too much or very poor oil in the sump, it could bet sucked into the inlet tract via the breather in excess and make the smoke. It could also be a bad or old batch of diesel you have in there.

There may also be a lot of residual oil in the inlet tract and intercooler if ther car has been standing and only just started up and moved a little way as typically happens when a car is for sale on a forecourt. A good run should see this gone. Don't worry about finding some oil in the intercooler and inlet tract as this is perfectly normal and just condensed crankcase fumes.

It is very unlikely to be the turbo causing this. They are very reliable and when they do let go, it is usually with clouds and clouds of blue smoke.

Test both the turbo and crankcase breather by disconnecting the air inlet to the inlet manifold so that the turbo and breather are effectivly out of circuit and the engine is drawing straight air direct. Also, you can take the EGR valve out of the equation by disconnecting the vacuum hose that goes to it. Leave it like this as the EGR valve serves no useful purpose.

If the smoke stops, reconnect the air inlet to the manifold but leave the breather disconnected. If you still have no smoke, the turbo is good and attention should focus on the breather valve. Occasionally, they do stick open, allowing crankcase fumes and oil to be sucked in the inlet tract unrestricted.

If despite all, it is still smoking, the valve stem oil seals must be suspect. They're easy to replace one the head is off... I'd not suspect rings as I'd guess you'd get hard starting and a loss of performance. On performance, the 406 is a much heavier car than the 405. Same with the Xantia, the 1.9TD is never as lively in those as it is in a 405. Also, yours will have a cat and anti-polloution measures which don't help.

I once saw a 1.9TD in a 306 burning oil so badly that if left idling for a long period, it would knock and race on acceleration as the oil was burned uncontrollably. That was stem seals. A give-away with stem seals is if the engine smokes much more after say, 5 minutes of idling and then being accellerated.

Don't worry over much about the temperature. A lot do seem to run around the 70 mark and a small rise in traffic is normal.

Test the thermostat by starting from cold and allowing the engine to warm whilst feeling the top hose. It should stay cold and them suddenly get hot as the thermostat opens. If it warms gradually then the thermostat is stuck open.

[r.welfare]

Jim, thanks for the welcome and the very detailed reply!

I will look into those items that you have mentioned when I get the car back from it's temporary storage in a couple of weeks. Hopefully it's something other than stem seals or the turbo - it certainly didn't seem to be "racing" at idle, just a bit lumpy.

Just out of interest, if the turbo was iffy, then presumably I wouldn't see the characteristic "soot" when it kicks in? I'm glad to hear that the 406 is slower than the 405, but it still seemed to pull harder once "on song". Not having a rev counter is a bit of a pain really!

[CitroJim]

Just out of interest, if the turbo was iffy, then presumably I wouldn't see the characteristic "soot" when it kicks in?

No, if the turbo was duff Richard, you'd really feel it. The car would be incredibly sluggish and put out rather a lot of black smoke, not the normal puff of black smoke as the pump over-fuel device kicks in on boost.

I'd hate not having a rev counter I miss it when I drive my dad's 205 diesel.

[r.welfare]

OK, finally this weekend I got round to giving the car a service.

First up, the air filter was pretty grubby so that went in the bin, and a new one went in. I checked the outlet pipe and that was clear, but haven't removed the EGR valve for cleaning just yet.

Then, the oil - it was over the full level on the dipstick, black and very smelly! Off with the oil filter (genuine Peugeot...but, having said that, it could have been there a looong time!), on with a new Mann one and the correct quantity of Castrol Magnatec diesel 10W40.

Finally, the cooling system was drained (looked like frothy cappucino in the header tank), flushed and refilled, after properly bleeding it. I must say that the bleed valves are MUCH easier to find in the 406 installation than the 405 (where they usually snap off on the thermostat outlet hose, anyway...)!

So - the car no longer smokes (except at startup - I'm waiting to regain energy/confidence to change the glowplugs - is the one on no. 4 cylinder as b****** hard to get at as the 405?), but it seems to idle a bit high - seemingly I may have stretched the cable a bit removing it from the air filter housing.

If I back the throttle cable off a bit at the pump, the idle becomes slightly uneven (engine shakes a bit on it's mountings) - but thankfully no smoke, like there was before. I thought injector no. 3 (with the lift sensor) might be faulty - the wiring into the mating connector looks a bit suspect. I will try undoing it while the engine is running to see if it makes a difference, perhaps. Also, is this (lift pump sensor) connection meant to be clipped to anything? There's a broken plastic clip around the cable between the connector and the injector, and a suitable metal "bracket" nearby, which makes me wonder...

Finally, under the front bumper there's a metal pipe that runs the width of the car in a tight S shape - this is clipped to the bumper on one side, but loose on the other. Any ideas what it is for, and whether it could be cable tied back in place on the loose side (or will it get hot)?

In conclusion I'm making progress - just a new set of (steel) wheels (with decent tyres) to collect and put on now - as two of the old ones are u/s due to dinged rims, tracking to sort out, a code for the stereo to be obtained and investigation of the central locking to finish - the plipper doesn't work, and the key (when in the driver's door) only operates the rear o/s door on unlocking, and doesn't even lock it again! I've checked the two relevant fuses for the ECU and they seem OK.

Thanks
Richard

[CitroJim]

Hi Richard,

Excellent news Pleased the smoking was nothing serious. Sounds like it was last serviced about 200 years ago

Don't I just know about bleed vales on 405s

The funny "S" shaped pipe I think is part of the aircon condenser and may be like that for expansion purposes. I see no reason why not to use a ty-rap on it but make sure it has a bit of free movement.

Glowplugs. The secret is to douse them in Plus-Gas, have the engine a little warm and use a good quality 12mm cranked ring spanner to remove them. Forget sockets and "special" glowplug tools, they're useless for these.

No.4 is not too bad if you stuff a rag behind the pump as No.4 glowplugs have a lemming-like desire to live their retirement out behind the pump and are a devil to retrieve; the rag stops this happening. Blu-Tak is your friend. Use it to catch the 8mm nuts as they come off and to refit them.

[r.welfare]

Thanks Jim.

Interesting comment on the S-shaped pipe - as the car doesn't have a/c! I'll try and get a metal clip perhaps, like the ones you get for CV boots.

OK, I'll have a go at the glowplugs next weekend. I have three genuine Peugeot ones "in stock", hopefully I can get away with just doing 1, 2 and 3

A bit of fresh diesel will hopefully sort the slightly rough "low" idle as well, although I am tempted to leave the idle speed as-is; the MOT emissions test for diesels is based purely on visible smoke when revved, isn't it?

[AndersDK]

According to Murphys Law - its always the no 4 glowplug without function. You can bite your neck on that

[np]

According to Murphys Law - its always the no 4 glowplug without function. You can bite your neck on that

Just changed all 4 plugs in my sisters 306.No 4 behind pump looked like it had never been changed,upon testing on the battery it was dead.No glow at all.At least the other 3 worked when tested

[r.welfare]

Bum. I knew you were going to say that. Better say goodbye to the skin on my knuckles in advance then

[np]

Your not that far away from me.I`ll offer to meet up with you if you want.I`ve got number 4 plug down to record time now

[AndersDK]

Undo feed wire from timer Relay. Undo "cucumber line" from plugs 1 - 2 - 3. Leave on 4.
Now ohms check each plug separately from tip (cucumber line on 4) to nearby clean engine earth.
You should ideally have 0.8ohm or 800milli ohm, which in real life equals a shortcircuit.
IF ever a plug fails, it ALWAYS does so by going high ohmic, from some 1.2 ohms and up.
A reading of 1.2 ohms or more is a sure NO GOOD.

You can instead use a heavy wattage headlamp bulb, and test the plug by using it as earthpoint for the bulb in a light test. The bulb should light up bright and clear on good plugs, and will always decrease in light intensity on bad plugs. May even not light up at all on disrupted (burnt out) plugs.

It MAY save you a change of no 4 plug ...

[CitroJim]

and test the plug by using it as earthpoint for the bulb in a light test. The bulb should light up bright and clear on good plugs, and will always decrease in light intensity on bad plugs. May even not light up at all on disrupted (burnt out) plugs.

It MAY save you a change of no 4 plug ...

Anders, that is one seriously good tip Anything to avoid the dreaded No.4 but as always Murphy's Law dictates that No. 4 is always the bad one

[r.welfare]

Thanks Anders, I will try that tomorrow morning with the help of my trusty multimeter!

np - thanks for the offer, still a bit of a trek for you to come here from Bristol! I'll see how I get on.

Car is in for MOT @ 3pm...fingers crossed, the blue smoke has pretty much disappeared but there's still a small cloud when it's revved hard (mixed with black when the turbo kicks in)...guess it's down to the discretion of my MOT tester.

[r.welfare]

MOT pass

Emissions were spot on, well within tolerances. All this has given me hope of success with the glowplugs tomorrow!