406oc.co.uk

I bought a 406 some days ago. I see a grey/white small cloud of smoke when cold start with a small missfire. After few revs its going good. Is this normal because i never owned a diesel ?

Don't know about grey but white smoke could be unburned fuel, how old are the glow plugs?

steve_earwig wrote:Don't know about grey but white smoke could be unburned fuel, how old are the glow plugs?

I really dont know, i bought the car 4-5 days ago. Also, at starting i can notice some small air bubbles in the fuel pipe that goes from the fuel filter into the engine lol(pipe is a bit transparent). Can the problem be from the glow plugs? I have some other issues and lots of questions about this car, if some expert on this field can talk to me live on skype/fb or anything i will be thankfull.

Does it start quickly? Both air in the fuel system and failing plugs can cause your symptoms.

sometimes it starts on one key at first time all normal, sometimes on 3-5 tries still on 1 key.
what can cause air in the fuel tank?

Hi & welcome

Definitely check your glow plugs first.

Does the glow plug light stay on for long? It should always come on for a few seconds -- long enough to put your seatbelt on if you're quick -- and you always need to wait for it. (I had a problem where the glow plugs turned off too fast and made starting very difficult.)

It's normal to see some bubbles in the clear fuel lines, but I wouldn't rule this out yet. When this is a problem it's normally a small leak that allows air to be drawn in.

after the small missfires after start, engine works normal. Glow plugs light stay on like 3-4 seconds then i ignite. my bigger problem atm is that car wont shut down and i must use 5th gear and brake to shut off AND remove one of the battery plugs to close the fuel valve that is failing to close since i washed my engine yesterday lol.

Oops! Was it doing the grey/white smoke thing before you watered your engine or has this only happened since?

Its always doing it on cold start with small missifires. i doubt on a glowing plug not working

Just wondered if your head gasket is starting to go.

Hard starting when its been standing over night indicates an air leak, if it struggles to fire after an hour or so I'd go for plugs.
Try squeezing the priming bulb before you try starting in the morning, it should be reasonably firm, if not you have air in the fuel lines.

If it's been serviced recently the XUD engine doesn't particularly like to self prime like the HDI so it may have sucked some air in on a fuel filter change (easily done and I have the T-shirt to prove it ).

Personally I'd do the following regardless as it won't hurt,
Take the lid off the filter housing and make sure the seal is clean and in good nick then tighten it down well (5mm Allen key I think)
Crack the union that runs into the fuel pump half a turn and pump the priming bulb until the bubbles stop then tighten back up (2 open ended 17mm spanners if memory serves).
It may still take a few cranks to start the first time but should be much better the next time.
If you can see fuel around the tops of the injectors it may be the leak off pipes so change them at the same time if they look suspect.
Also check the priming bulb itself as they can perish over time but not overly common.

After all that if the problem persists I'd do the plugs, 2 are easy, 1 is fiddly and the fourth is erm...challenging.
I only changed 3 on mine and it started first time every time even running on veg oil.

Good luck

I found if you flip the metal intake over to the front of the pump you get better access to the awkward plug.

i dont doubt that the low amount of fuel makes the fuel pump take air into the engine . the tank is 70 litres omg i never knew that xd. Engine runs perfect after the first ignition in the morning and no problems. a little bit of black smoke under rev its normal i think. I fell in love with this car omg. Btw, u say u put veg oil in it ? will it keep the same power or it will decrease while on vegetable oil/diesel fuel mix? Can i use burned oil from the fastfood's for example? I have bosch not lucas and i read somewhere that bosch loves oil. but, does it have any side effects from running on mix?

Thanks for the answers and im sure that it has air coz i saw bubbles going in the pipe from the filter to the engine this morning.

Soak the glowplugs in WD40 every day while the engine is hot for a week or two before attempting a glowplug change.
Change them with the engine still hot!

Glowplugs and a fuel filter will solve your starting issues!

If running waste oil it must be filtered very well which was always too much faffing for me, I just bought sunflower oil from Tesco which is currently £8 for 10 litres.
Some people run 100% veg but I found 50% in the summer and 1/3 in the winter and had no noticeable drop in power or economy.
You'll probably have to swap the fuel filter after the first and possibly second tank full and a shot of Redex or your cleaner of choice in every other tank of fuel.

I strongly advise you sort your fuel and glow plug issues before putting veg in as you'll need both working properly