Grey smoke and rough idle

[thatfatbloke]

Hi - the old Synergie 1.9td has over the past few weeks started to chuck out grey smoke and is rough on idle when starting from cold. This only lasts for a few seconds then runs fine after that. Always starts 'keenly' - ignition on,wait for piggy tail light to go out,count to three,and away she goes. Glow plugs were changed 27,000 miles ago,could they need doing again?. The plugs previous to the last change only lasted 11,000 miles before they needed changing!!. Is this the engine that the end plug is a pig to do,so can often be left?. What make are best?. Thanks.

[the_weaver]

TD's going through glowplugs in a short time is a known problem. Some plugs aren't quite up to the job. The best plug to get is made by Beru. They last a long time. You can get these from Gsfcarparts. Make sure you get the ones for the turbo.

Paul

[andy5]

Glow plugs ought to last longer than that. My old BX TD did 180,000 miles in my ownership and they were never changed.

If they are burning out, I wonder if they are staying on all the time. Do you hear the relay clunk to turn them off, slightly after the light goes off?

If they are working fine, then you could try having them on for two cycles and see if that reduces the smoke. My previous BX a non-turbo, became more difficult to start and smoky with it, ok once warmed up, and I took it to someone who did a compression test and reshimmed the valve clearances. As you say yours is still easy starting, that seems less likely though.

[CitroJim]

Check with a voltmeter on the glowplugs them selves that they are getting at least 11V when active and that they hold on until the relay clicks off...

I'd say that if the engine starts easily then that part is Ok and the glows are initially heating normally. What may not be working is the post-heat function - in IDI turbo engines the glowplugs come back on again once the engine has started and will glow until either the coolant reaches 60 degrees or the throttle is opened beyond a third. Check that they do continue to glow after starting and when the engine is idling. They can glow for some good few minutes and this is hard on poor quality glowplugs.

Make sure you have the right ones. Although turbo and non-turbo glows look identical they are not interchangeable. non-turbo ones are not designed for lengthy post-heating and will soon get poor.

The correct ones for you are BERU GN909. If offered GV636 or equivalent these are the non-turbo ones and will have a very short, if not brilliant, life..

[Richard_C]

My Synergie (also 1.9TD) displays the same behaviour intermitently. Usually starts fine, sometimes starts but smokes and grumbles for 15 seconds or so. The common thread seems to be how long the pre heat light stays on. Normally its a 'count to 10' but sometimes it's a 'count to 3.' That's when it gets smoky, so in my simplistic way I reckon it is something in the pre heat timer control. The simple answer is to watch the light, if it goes out too quickly then ignition off and start process again. It always starts cleanly the second time. Only takes a few seconds extra, and as the car is a 'useful spare' and only worth about a shilling now it's hardly worth doing expensive diagnostic work.

[Xantidote]

a shilling

??

showing your age !!!!

[jgra1]

chaps, is there a way of showing the glowplug condition, and also the post heat relay duration.. from inside the car? like 4 lights? or something? (I guess the current draw to each plug would make that impossible, not forgeting the parallel wiring) - I appreciate that even a GP wih voltage, the apprears to be working, may have a bad glow.. so any dianostics are limited..

maybe just a dig voltmeter, on the feed wire.. 4 working = 11v for example, 2 working = 12V or whatever.. would show the post heat possibly too..

I am not being lazy, but it would be nice to have an onboard daily diagnostic on them.. they are about (touch wood) the only problem i have with my TD..

John

[Xantidote]

Hmmm, well John,

Don't think I can come up with anything better than your idea of digital voltmeter linked to the GPs feed. You'd then learn the normal voltage display with all GPs working, and the duration. Om my TD, I can hear the relay click off after the post-heat period, but only when the engine's not running, so not a lot of help once engine's started! Actual voltage would depend to some degree on the battery condition.

Are you looking for work though? From my own experience, my car will start through the summer/autumn with 1 GP failed. It's only when 2 have failed in the cooler autumn weather that the engine churns over for a longer period, ultimately firing very lumpily with much smoke. That's a good enough indicator for me that something need checking out, and I always then check the GPs first (never been anything else)

cheers - Martin

[jgra1]

thanks for that Martin..

I dont know.. just nice to know exactly whats happening..

this morning almost impossible to start, 1 week after removing all 4 and reaplacing two..


I could just be very unlucky with them, or WVo could be killing them off..
but, this morning, it wasnt that cold..

dont know.. I just want a daily diagnostic so I can think about the fuel viscousity or / and air temp..

Sorry not being clear really.. it would be nice to see all plugs are basically on, and are going off at the right time every day.. even just for a week or two.. piece of mind really

[Xantidote]

Ah, right,

this morning almost impossible to start

understand your interest. Well, maybe even a temporary connection of digimeter on to feed wire would tell u something, but bit of a pain if you're dashing to work. You've tried going through the glowplugs cycle 2-3 times before spinning the starter to see if that helps?

[jgra1]

yep, a double to get her going, another double for the retry, then some singles as i had to go and open the gates, cant leave her for a second

I suspect in reality, it's GPs failing often, for whatever reason, and thick WVO, both together just make starting the xant a pain in anything but summer..

I can live with it..

[Xantidote]

I only use derv, & know nothing of using WVO - maybe that's not helping? At least you get the car started.

Living with the problem will help you identify it more accurately. May be worth sometime trying some Beru GPs as Jim refers to above, even if just in the more easily accessible cylinders. Interested in how you resolve the problem (and hopefully before winter arrives )

good luck - Martin

[jgra1]

thanks Martin

dont worry, been living with this for the last 3 winters / years.. glad the battery is good mind.

benn on WVO for about the last 50K miles

[CitroJim]

John, when she's being difficult can you see any smoke coming out of the exhaust? If bad starting is solely down to bad glowplugs you'll see grey smoke issuing from the exhaust during prolonged start attempts. This is escaping unburned atomised fuel.

If you see no smoke at all then you can lay the blame at the WVO being reluctant to do it's things...

[jgra1]

all grey Jim

smells nice I think

lke i say, not too worried, she always starts in the end