Xantia 1.9 TD smoky start up SOMETIMES

Unread post by **aerodynamica** » 06 Sep 2011, 22:06

Hi all, my Xantia 1.9 TD coughs out blue smoke occasionally on start up and soon clears - first thought is valve stem oil seals but why would it be only sometimes - usually after a few hours' wait rarely first start of the day and even then, it's only sometimes it burns oil.

Anyone been here before?

Unread post by **Peter.N.** » 07 Sep 2011, 09:15

The smoke probably isn't oil, I suspect its unburnt fuel, you should be able to tell by the smell, fuel has a sweet paraffiny type smell. Whether it does it or not depends a lot on the ambient temperature and glow plug condition but most diesels of that age will do it. Its just that the engine is not fully firing on all cylinders when cold.

Peter

Unread post by **RichardW** » 07 Sep 2011, 12:12

If it's done lodsa miles too, then exhaust valves can close up, causing a minor loss of compression on cold starts that can make then cough. A 94 TD won't have any valve stem seals

Glow plug change on a Xantia TD is a lovely job

Xantidote · Unread post by **Xantidote** » 07 Sep 2011, 18:54

Well, my 1995 TD does have valve stem oil seals.

I tend to agree with Peter, in that the haze you see on start up may be the result of incomplete combustion - perhaps one cylinder is a little lower on compression. I notice a bit of smoke from mine, but more so in the colder weather, when the engine block is that much colder, and the battery may be spinning the engine less energetically. Sometimes this smoke on start up makes me do a check to make sure all glowplug working.

I'd not bother thinking of doing the stem seals unless the blue smoke was really bad - too much work and hassle for just a little improvement

Unread post by **aerodynamica** » 07 Sep 2011, 19:06

Cheers for the replies folks, I'll test the plugs using the test-with-finger-from-cold method outlined somewhere else on here.. But the fairly comprehensive list of work done to the car has it that the plugs were changed twice since 2001 so I'd hoped they'd not be the issue. It didn't smoke at all today though.

Occasionally there is a bit of a 'thrum' from the engine under idle: like one cylinder is misfiring occasionally but it always clears. I wondered if changing the fuel filter would help on this but it seems to always go away after a couple of miles. Any higher revs are smooth as a diesel can be!

I thought the idle was hunting up and down a bit as the tacho was 'twitching' however, it's still twitches occasionally while running is smooth - hopefully just a fault with the tachometer? How does the tacho pick up the revs on a non-electronic diesel?

The car has done 108K miles since new but in 2004 had the engine replaced/rebuilt (not sure which) after sucking in floodwater.

It does go very well though with plenty of poke on the motorway and a nice light clutch.

Chlorate · Unread post by **Chlorate** » 07 Sep 2011, 19:26

Mine smokes a bit on the first start of the day, methinks it's just part of owning an old diesel though.

The lumpy cold idle could be to do with the cold idle thermostat not tugging hard enough on its cable, I know mine doesn't work properly but I've never been that bothered by it. Touch of the accelerator pedal does the same thing.

The tacho is fed by a little passive sensor attached to the bellhousing and reads engine speed from the flywheel, they're not particularly reliable.

-Alex

Unread post by **Rhothgar** » 09 Sep 2011, 21:20

It is possible that ONE glowplug on either end is inevitably going to give up the ghost.

Hopefully NOT the one behind the pump!

Check out my posts. I posted sometime around 3-4 months ago with videos of how bad mine had got after the plug had gone completely.

I couldn't believe just how bad an effect it had had on the idling.

I am actually typing this on my iPhone so it is a right pain in the proverbial otherwise I would add a link to my other post!!!

Unread post by **aerodynamica** » 16 Sep 2011, 19:46

Well, thanks all. I am less worried about the smokness on start up now as I'm confident it's more of a grey coloured smoke as opposed to the blue that I feared it might be..

At least it starts.

Update though: I notice that it seems to take a fair bit of cranking to get it to fire but only when it's warm/hot. If i start it from cold it fires up well - sometimes a bit smoky. But if I stop the car after a run, restart after say 5-20 mins, it'll often take a lot more cranking to run.

I always give it preheaters regardless.

Any ideas here - could it be leaky fuel line?

Unread post by **CitroJim** » 17 Sep 2011, 08:46

My experience with the Bosch VP20 pump is that they do suffer from hot starting issues a little as they age. This I put down to small amounts of wear here and there making it slightly less of an efficient pumper when hot and full of hot diesel. Things expand and clearances open up.

Basically, it can be taken as normal. IDI engines like the 1.9TD always need glowplugs on every start, hot and cold - it's just the nature of the beast.

TDs are always a little more reluctant to start the their NA bretheren due to having a lower natural compression ratio.

For the cold smoking and general lumpiness check your glowplugs are post-heating properly; basically they should re-ignite after the engine starts if the coolant is below 60 degrees and the throttle is less than a third open. Under these circumstances the cold advance will be in operation - this can be checked by seeing 12V on the cold advance electrovalve on the front of the pump. Both a lack of post heating and cold advance will cause poor cold running just after the first start of the day. Non-ECU diesels have a collection of special relays to look after this.

Finally, check the right glowplugs are fitted - BERU GN909. Although the NA type will fit and look identical, they're wrong and will soon grow weak under repeated post-heating and give the symptoms you have Graeme..

Grey smoke is down to inefficient combustion and is partially burned diesel. A tight valve, a bit of a dicky injector or any of the above can all cause and contribute to it...

Hope that helps a bit..

Unread post by **Peter.N.** » 17 Sep 2011, 10:18

The starter motors get tired on these too, I just fitted a new one on a 405 and it turns at about twice the speed it did. Taking the starter apart and lubricating the reduction gears improves them a lot and they certainly start easier the faster they turn.

Peter

Unread post by **Old-Guy** » 17 Sep 2011, 17:25

This sounds familiar - I had much the same problem last winter.

Complete cure was a new, good quality (Varta) battery and replacing the leak-off pipes.

Now I know this sounds weird but I think it's all down to getting all 4 cylinders firing 'instantly':

New battery can spin the engine over that bit faster and maybe the glows are a bit hotter too. No air leak means all 4 injectors are injecting from the start (into hot air). If fuel doesn't reach one cylinder for a couple of cycles, then when it does it's the same as starting with a cold glow plug - takes a couple of cycles to catch while unburnt fuel goes down the exhaust.

Replacing the leak-off pipes is cheap (motor factors stock a kit of a length of pipe (that you cut to length) and a plug to blank the end. You might find that they've all been changed except the one behind the pump which is a bit harder to get at!

Unread post by **aerodynamica** » 12 Oct 2011, 06:50

Update on this:

I changed the 4 heater plugs and cleaned up and examined the series connection cable and refitted. Results were good - smooth, quick starting.

Yesterday morning it started without a hint of smoke. Result.

Until lunch time yesterday I had to go out and upon starting (not from stone-cold obviously) it was back to its old ways of shuddering and bluey-grey-white smoke for the first 5 secs or so.

It then clears and doesn't recur until the next <5hours lay up.

So back to square 1, it seems to not have improved at all.

Recap: it tends not to smoke at first start in the morning (but occasionally will), it never smokes on restart after a lay up of a couple of hours. It smokes on start up if left for 5 hours.

It never seems to affect actual starting or running though.

With the new plugs I'd tend to think it is caused by something else. Just what though?

mongoose100 · Unread post by **mongoose100** » 12 Oct 2011, 08:14

aerodynamica wrote: With the new plugs?

Were they decent quality ones? I've found some of the cheaper ones like to burn out almost on a monthly basis!

rabenson · Unread post by **rabenson** » 12 Oct 2011, 08:41

Have you tried a bottle of Forte injector cleaner in half a tank of fuel followed by a good "Italian tuneup?".

Unread post by **Peter.N.** » 12 Oct 2011, 09:31

Have you checked to see if there is actually voltage on the glow plugs when you start it? Apologies if this has already been mentioned.

Peter