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Peugeot 306 Problem2 - 156v6
Me again with the 1995 306 D Turbo.

I have a smokey problem on startup.

When starting from cold, there is no smoke for the first minute or so, then suddenly clouds of the stuff (greyish) come out till it's heated up. Once its heated up, the smoke stops completely again and it runs well.

My first thought was the glow plugs, so I've just finished replacing them (a real pain in the butt), and the problem is still there.

Any suggestions anyone as to where to look next??


Peugeot 306 Problem2 - lauriew
Glowplugs usually on a timer..they keep "glowing" after engine has started even though light has gone out.This is to keep engine running til warms up slightly and, subject to temperature, may only do this for (say) 30 secs.
Peugeot 306 Problem2 - Andrew-T
Laurie's problem doesn't sound like glowplugs to me (especially since he has changed them) but may be to do with a cold-start device which should be adjusted to behave properly. I thought glowplugs only 'ran on' for 5-10 secs after the dash-light goes out.
Peugeot 306 Problem2 - Andrew-T
Of course I mean Phil's problem - Laurie doesn't have one, does he?
Peugeot 306 Problem2 - diesel 306
cant say thats true otherwise the glow plugs would burn out as when diesel fire first start its away.
Peugeot 306 Problem2 - dieselhead
Assuming it's not steam in the exhaust caused by cold running (could be if you do alot of short journeys)...

My first thought is that it's air getting into the fuel..I would fit a clear plastic pipe (if their isn't one their already) between fuel filter canister and the injection pump and check for air bubbles..
I would also suggest you give the injectors a clean. The needle valves in them can stick due to deposits building up causing them to get dribbly.
This trick was passed on to me by my local mot station when my 205 diesel failed it's test on emissions .

Warm up engine
.Drain fuel from filter canister using water drain tap
.Remove fuel filter
Fill up canister with injector cleaner (car plan nitrox worked worked well for me)
Re-fit top and run engine at a moderate speed. To finish off you should put the rest of the injector cleaner in the tank and give it a good run . don't forget to put the filter back though.

If this fails i suggest you get a specialist to check the pump (theirs a tamperproof screw at the back to set the fueling with).

It could also be a cracked cyclinder head/head gasket that allows water into the cyclinders if the cars radiator needs topping up very often

hope this helps


Peugeot 306 Problem2 - RichardW
The glowplugs on an XUD should stay on for 3 minutes or until the coolant gets to 60°C (on later cars) after the engine is started. They switch off about 20s after the light goes out if the engine is not started to stop them flattening the battery. It sounds to me like the plug controller here is switching off the plugs too soon. You should be able to measure the voltage from the plug harness to earth and time how long after engine start they switch off, Mind you, if it is wrong, then trouble shoorting might be difficult. Middleman will probably be along with some bright ideas!

Peugeot 306 Problem2 - 156v6
Thanks for the replies.

Whoops, I forgot to mention that I've thrown a load of injector cleaner into the tank already...

It's definitely smoke not steam (I'm thinking of selling the car to the army to use for making smoke screens if all else fails).

Dieselhead - If it was air getting into the fuel somewhere, do you think it would completely stop smoking after its warmed up? I would have guessed (and I'm a total novice with diesels) that the smoke would continue all the time???

b*****, I'm starting to think I might have to rip the head off...



Peugeot 306 Problem2 - IanT
Don't know the answer to this one, but it doesn't sound like either glow plugs or an air leak to me. (Have a look at the parallel thread "306DT Starting" www.honestjohn.co.uk/forum/post/index.htm?f=4&t=10...1 ).

The glow plugs help by staying on a short time after the engine has started, but their failure to stay on should not cause "clouds of smoke" more than a minute after the car has started.

Air leaks should also cause difficulty with starting. Once underway the effect of an air leak is not normally noticeable, though in that other thread Dieselhead refers to an occasional misfire on hard acceleration.

Peugeot 306 Problem2 - 156v6
Thanks again for the replies, much appreciated.

One more symptom that I forgot to mention. When first started you can push the accelerator as far as you like but the revs won't rise. Does this help at all??

I timed the post heating of the glow plugs, and it's 3 mins as it should be.

I'm going to fit the new fuel filter £ line later on (when I work out where the bleed screw is?!), but if that's not it, then I recon its out of my league.

The best suggestion that I've been given is that one of the injectors is misaligned/worn out or something, so I'll have to pass it on to a specialist.

Can anyone recommend a diesel injection specialist in (preferrably) east london) who doesn't charge like a wounded bull?

Cheers and thanks,

Peugeot 306 Problem2 - dieselhead

I would put money on it being an air leak - the fact that you can nail the throttle when you start up and nothing happens suggests to me their is alot of air in the system...white greyish smoke on a diesel is indicative of a weak mixture so this would seem to support this. If it was dark grey/black it would be overfueling..I think you can forget about a cracked head/gasket in my very humble opinion...

What i think may be happening is fuel is draining out of the filter overnight and when you try to start up the engine has to purge the air out of the system ...once the engine has warmed up and is running faster the amount of air coming in isn't sufficient to cause the smoking..

This doesnt seem to be an uncommon problem with 306's judging by the amount of threads about it on here and my experience of my own 306DT which has always suffered from the odd misfire because of air in the fuel...mine has a clear plastic pipe to the pump so you can see the bubbles.

I would check all the connections are tight...fuel filter top.. gasket and then go from their...

good luck with it

Peugeot 306 Problem2 - Ross_D
I wouldn't have thought that a 'weak' mixture in a diesel would cause smoke; the less fuel you inject in, the slower the engine runs, thats how diesels work!! I would agree though, that there is an airleak somewhere letting air in to the system, as others have said. I have heard somewhere though, that the fuel filter housing itself can deform and cause leaks, this maybe worth looking into if all else fails.

Peugeot 306 Problem2 - dieselhead

yep it is true that a diesel engine isn't throttled...the power output is controlled by the quantity of fuel imjected...
I was trying to make the point that the air in the injection pump would disrupt the fuel injections on random cyclinders causing them to misfire (this could happen if fuel mixture was too lean to burn or not atomised correctly)..This causes the emission of completely unburnt fuel at low temperatures - at higher temperatures the fuel burns off more easily.
Another cause could be poor compression/pump timing incorrect..

Peugeot 306 Problem2 - 156v6
Hi all, at the risk of sounding stupid...

1) Is there a special sort of fuel line (clear) that needs to be used for diesel? Where do you get it from? (I tried Halfords and my local garages with no luck).

2) Where the h*ll is the bleed valve on the fuel line?!


Peugeot 306 Problem2 - IanT
1) I suggest you only use a transparent fuel pipe as a temporary fault-finding measure, and replace with ordinary pipe when all is fixed. I don't think you will find anyone selling it labelled "diesel fuel pipe" because it's unlikely to have the right chemical or physical properties to withstand the fuel for a long period of time. So you will have to find some from another source - probably with an 8mm or 9mm internal diameter. For instance, the clear reinforced pipe attached to my Waxoyl spray can looks about right - but I've not tried it myself!

2) If there are only bubbles of air in the system, then there's no need to bleed the system. Running the engine will suck the air through with the fuel and the bubbles will disappear within a minute - unless there's an air leak letting more air in!

Even when you replace the fuel filter, it is only necessary to pump the priming bubble a few times (until it is hard) to pump fuel through the new filter. There's no need to bleed the system. The car may hesitate and stutter during its next start, but it's not a problem.

But if you really need to, my 1993 306 diesel (with a Lucas Injection Pump) has a plastic bleed screw in the bottom of the fuel filter just where the fuel inlet pipe enters the filter. Other models may have a bleed screw next to where the fuel inlet pipe enters the injection pump (mine hasn't). Failing that, you will need to loosen the pipe itself to let the air out while priming.

Peugeot 306 Problem2 - PhilW
I'm a bit worried about these glowplugs that stay on for 3 mins after starting. On my XUD engines (3 so far)they have stayed on for about 7 secs and you can then hear the relay click off - I'm sure I read that this was right and it certainly was about this time even when I had to get a new relay - (that little blue box thing on nearside front wing of a BX. Am I wrong about this? Mind you, I can't see what this would have to do with the original problem. Certainly sounds like an air leak to me.
Peugeot 306 Problem2 - Troubled Tom
you can get them tested for about twenty five quid i think for all 4. I am going to use a place in Watford
Peugeot 306 Problem2 - Robin the Technician
As a fully qualified car & commercial technician of some 35 yrs+ some people here are giving you wrong information. You need to check and if necessary change the following: air filter, fuel filter. You don't need to fit plastic see through fuel lines as the minute the vehicle gets and air in it, it won't start. The injectors are probably non servicable but only by taking them out and having them tested by qualified personell with access to a hartridge tester can do this. From what you describe it sounds like the most likely problem is injectors. They are designed to inject a fine spray a extremely high pressures but if the pintle becomes worn or bunged up they don't work well until well heated. You may be able to find a company in yellow pages under diesel injection service or ask your local bus garage maintenance shop where they recommend getting a set of injectors tested.
Peugeot 306 Problem2 - 156v6
Thanks again for all the advice.

OK, so no need for bleeding or putting in clear fuel line, but I might try some clear line anyway, just so I can see if there's "loads" of air in it. Regardless, will replace the hoses with new standard ones in case they're b*****ed somehow.

Re the glowplus being on for three mins, this is all fine - my voltmeter is telling me that the plugs stay on at a high voltage for the first 5-6 seconds, you hear a click and the dash light goes off, after starting the car, the plugs stay in at a reduced voltage for three mins.

Looks like I'm off to see an injection specialist soon. Will post the results later.


Peugeot 306 Problem2 - 156v6
Oh, I forgot to ask. Is there such a thing as a good or bad type of injector if I need to get replacements? Must be cheaper over the net than from a (esp peugeot) garage, any suggestions??
Take advice with care. - M.M

Your problem "could" turn out to be injectors but don't discount 15 useful posts on the word of Robin the T... because he gave odd advice in his first post on the forum** and he's doing it again here.

**Sorry Robin but it's true, you were so wrong to say that a diesel should normally run like a pig for 20 sec after starting.

Air ingress in modern diesels will give a variety of odd faults but because they are very good at self bleeding they will start and run with some air present.

A major car maker a few years ago had an air ingress problem on a newly introduced diesel and the "mod" was to fit clear plastic tubing just before the injector pump so you could see the air bubbles and know why the car was running badly. The cars suffered surging but never actually stopped.

Take advice with care. - Edward
My 98 306DT has a (factory fitted) clear plastic tube between the fuel filter and the injection pump. Very occasionally I have seen a few bubbles immediately after starting but these cleared. The engine always ran fine. I haven't seen this since the last service which include a new fuel filter.
Take advice with care. - 156v6
Me again.

Just fitted a new filter and replaced the filter-pump fuel hose(with original stuff, not clear as I couldn't find any!).

Anyone want to guess the result? Problem still there. Gonna have to assume it's an injector I guess.

To get them tested is probably not cheap? Andyspares has injectors for £35ea so replacement might be easier/better than testing since after 78,000m they're probably getting a bit tired anyway?

Nothing special needed to put in new injectors I hope???

Take advice with care. - PhilW
I'm no expert - all I can do is speak from my experience. I had similar problem to you and I replaced the fuel filter - made no difference. I put a length of clear hose (as quoted above like Waxoyl pressure sprayer hose) and found air leaks. There were two leaks, one from fuel filter housing and one from a loose pipe coming out of the fuel heater behind the engine. Like MM says, diesels do start with an air leak if the engine is turned over for long enough, but with a lot of smoke. Does priming the fuel filter first improve starting (can't remember if you mentioned this earlier). If you do have an air leak replacing injectors will not solve problem but will cost you. (£135 for injectors alone). Testing for air leak costs nothing. 78k is not far for injectors, on my Bxs I have done 170k and 140k without replacing one, and I bet some could quote double that. Test for the air leak! Where are you - I bet there's someone nearby who could lend you a bit of hose!
Peugeot 306 Problem2 - IanT
78K isn't old for injectors.

Personally, I would perservere with the cheap options before forking out £140 (plus something extra for the various washers and a deep 27mm socket). Maybe Peugeot did factory-fit clear hoses in 1998, as Edward says - it would be worth asking the Peugeot dealer.

On the other hand, I'm not convinced that an air leak properly explains your symptons - car starts and runs without stalling, but no response to accelerator (no smoke mentioned at this stage), followed by clouds of smoke after one minute, continuing until engine has warmed up.

So Robin might be right and it might be injectors. But since it is only "might", it would be a better gamble to get them checked by an injector specialist first.

If you do go ahead and replace the injectors yourself, please let us know how easy/difficult you find it - useful knowledge when the day comes when I want to do it myself!

Peugeot 306 Problem2 - 156v6
I finally switched my brain on and got hold of some clear tubing - looked in the yellow pages under "hydraulics".

All fitted and I must be the only peugeot owner who has no air bubbles whatsoever.

Course this doesn't solve my problem, so I phoned a diesel specialist (again from the yellow pages - Essex Diesel Injection Services - has anyone heard anything good or bad about them?) who tells me they can whip the injectors out and test 'em (£40), and if need be replace the tips for £24 each.

Sounds pretty reasonable to me? I'm assuming that replacing the tips means they're as good as new (if the guy isn't a cowboy)?

Will update the progress when I get the time to take the car in...


Peugeot 306 Problem2 - 156v6
Guess who's back? Yes its me....

Long story cut short, but I've just taken the injectors out and had them tested, apparently they're all fine, which I'm not happy about since it means I'm back to square one again.

Very easy to do in case anyone else is wondering (27mm long reach socket was a fiver at halfords, nothing else special needed), and a lot easier to replace then the glow plugs.

Thanks to Essex Diesel Injection Services in Greys who tested them for me, gave me new washers to put in when refitting the injectors, and all for free!

So, I still have a smokey car. Gonna take it back to the injection guy soon as he said he'd have a quick look for me to see if he could see anything.

If he can't see anything obvious, all I can think of now there might be a carbon build up somwehere inside (one of the injectors had a tiny build up) so I guess ripping the head off is next... Or to try to flick it on to some other sucker (after warming it before they come round of course). Anyone wanting to buy a car?

Always happy to have any hints from anyone!


Peugeot 306 Problem2 - Dantheman
Looks to me like all the other guys have been running you up the garden path whith "weak mixture" and so forth. First things first Whats the milage? Haveyou gone through water at all? (i.e. sucked up in to the engine) Have you over filled it with oil ( it may have worn piston rings that would acount for it clearing when warm.) why not just get you local dealer to spend half an hour on it. It should only cost you around £30. Take it in in the evening an leave it with them over night so thay can test it from cold. In stead of "try this and try that" Which in the long run you end up spending more money and wasted time flapning around! Whith this kind of fault you cant diagnoise in a chatroom a good mechanic must see the fault for himself. Then go from there!
Peugeot 306 Problem2 - dieselhead
I partially agree with Dantheman ..Phils Peugeot does need some attention by a technician with the right test equipment - their is alot to be said for consulting somebody who deals with this sort of problem day in day out. However alot of car mechanics i know dont have a clue and make snap diagnosis and just replace parts willy nilly (costly) or try to fob you off by saying 'they all do that'
it is true that white smoke is caused by a weak air/fuel mixture. Their may be enough fuel their but not enough heat (low compression) or mixing with the air (unlikely now the injectors have been checked) or combustion is occurring too late so that their isn?t enough time for fuel burning . Understanding this is crucial to diagnosing this fault. You cannot burn neat diesel fuel in an engine in the same way you cannot burn a bucket of diesel by throwing a match into a bucket of fuel - the diesel must be finely atomized and mixed with the air and also heated to vapourize the droplets to form a combustible mixture. I think after 78k miles it?s highly unlikely that the rings will be worn. Wouldn?t the smoke be blue not white if it was a ring fault ? If the car had ?sucked up water? I would expect Phils conrods to be banana shaped and the engine to sound like a bag of bolts.

It Does seem like alot of the simpler (and inexpensive) causes have been eliminated which is the right way to go.
Does the car seem down on power to how it was before the smoking started ?.. my 306 DT will do just over 70mph up a very quiet 1 in 6 hill in 5th gear so your car shouldn't feel in any way sluggish..
Other basics to check are that the cam timing is ok (i think you have to take of the starter motor off to do this)..by checking that 8mm bolts will engage in the alignment holes in the flywheel, pump and camshaft sprocket ..If it's out i would get an experienced mechanic to adjust it as its very easy to get it wrong and bend a valve on these engines..
I would also get a compression check done ..if it's low on one or more cylinders i would take off the cam cover and check the valves have enough clearance before taking the head off.
It would also be a good idea to check the pump timing.
I can only remember having to put about half a pint of water in my 306's radiator every few months ...if yours needs more i would suspect a head gasket problem

Peugeot 306 Problem2 - 156v6
OK, I think I'll check the valve clearance, then it thats OK, its probably out of my league, will have to drop it off to a mechanic when I get the chance for a compression and timing check.

Thanks for the advice, will update progress again when I get it checked.


Peugeot 306 Problem2 - evanesce
i'm thinking of buying a '94 306 xldt 1.9 in the next couple of days for 2k with 120000 miles on the clock.
all these problems are putting me off.
any advice?????
Peugeot 306 Problem2 - IanT
Evanesce - This is one 306 with an unusual problem, and doesn't reflect on the general reliability of 306 diesels in general (or any Peugeot/Citreon XUD diesel). So don't let one car put you off.

On the other hand, 306's have their fair share of faults with the non-engine bits.

£2K sounds about right for a dealer sale with a decent warranty; a touch high for a private sale.

Peugeot 306 Problem2 - 306 TD Driver
You say this is an unsual problem for a 306? cos im facing the same thing as the first guy.

on start up my 306 TD chucks out a big cloud of grey/blue coloured smoke, and for a few mintues struggles to pull away. it seams to choke and stutter, this only happens when in 1st gear and low revs, once the turbo kicks in or i change in to 2nd the problems just disappears!

i tried a number of engine cleaners but to no joy, so i have replaced all 4 of my glowplugs with NGK (2 of which where jet black with soot!), found the problems started to disappear, only to have it return 3 months later, when the battery died on it. now the battery has been replaced the problems has disappeared (but for how long is anyones guess!).

i would recommend seeing if the battery is the orignal as mine was, after all the glow plugs use electricy to heat up, so they dont heat up right and slowly drain the battery even more!?!
Peugeot 306 Problem2 - leatherpatches
..and you wouldn't be the only one with this problem. I have smokey startup, but otherwise excellent reliability and performance from my 98 DTurbo 306. I have run it like this for nearly 40k miles with no other problems.

So it looks like some of us will just have to put up with an enormous puff of smoke over the neighbours in the mornings.
Peugeot 306 Problem2 - 156v6
It\'s been a while but I\'ve got it cracked finally.

I chucked the car at an injection specialist, and after a few false starts he found that the pump timing was a bit out - not a lot, but enough apparently to cause the smoke after startup.

Easy to fix, and only £70, praps I should have given it to him straight away rather than messing around for ages myself.

Anyway, long story cut short - its done. Yay!

Thanks a load to all those people that gave me suggestions, much appreciated.


Peugeot 306 Problem2 - Davektk
Phil (and others with smoky 306 DTurbos)
I've got similar problem with my N reg 306 DT on start-up (it's done all of 66,000 miles). Peugeot dealership said that in 90% of cases replacing glowplugs fixes problem - £140 and no change. Now they say another £300 for replacement nozzles on fuel injectors will solve problem. I've read this thread and don't believe them. Thoughts?

Think I'll call Essex Diesel Services tomorrow and get a comparative quote - I imagine it'll be half or less. Most importantly I need to decide whether to even bother going down the road of trying to fix it if I'm not willing to spend much more ££ nor take the time myself to have a go (don't have the knowledge to even try).

Have I been totally ripped off paying £140 for glowplug changes, and at 66,000 miles should they be "almost gone" as the garage says?

Peugeot 306 Problem2 - solara
I replaced my original glow plugs on my 306 at 120,000 miles (9 years old). They werent actually causing me a problem, but I thought it was time. On checking them, all four glow plugs were still okay. Of course mileage isn't a good indicator, as more wear and tear is caused by many short stop and start intervals.


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