Technical Carcinogenic Punto JTD

[Crowmark71]

Our 48,000-odd mile 2003 Punto JTD has a nasty smoking habit. There have been no warning lights on the dash, no discernible loss of power since we bought it, no hesitation/flat spot while accelerating, but about 2 yrs ago I was towing a loaded trailer with it and when booting it away from a 30 limit saw a hefty smokescreen from the rear. Didn't do it when it was just me so I ignored it, but it's grown steadily worse over time and now smokes under acceleration with just me in the car and no load. Doesn't really appear to smoke until it's up over about 1800 rpm and full throttle. I had thought it was knacked turbo oil seals as I'd had the turbo-to-intercooler hose off a while back whilst chasing oil leaks and found a fair bit of oil inside both it and the intercooler (not pouring out but a good coating). But I've taken the turbo off today and there's noplay at all in the bearings/shaft at either end and there's oil on both thte inlet and outlet side of the turbo, making me think that the turbo's OK, plus the breather hose between the cam cover and the air filter had oil in it, again not a supertanker full but enough to drip a bit from the hose when disconnected, so I wonder if it's this feeding the oil to the engine and causing the smoke? Said smoke, by the way, is dark grey in colour (not white or blue), so black if you will. I've also had the EGR off and cleaned it and apart from some soot it was OK and operated fine (can be heard to click when the ignition is switched on) and was nowhere near as clagged as some I've seen.
I'm loath to shell out for a refurbed turbo if there's nowt wrong wi' this one, so opinions are welcomed, my current idea is bang it back together, fresh oil & filter, new air filter (to see if that helps), a couple of bottles of injector cleaner and a good thrash before the MOT on Friday to see if that cures it, unless anyone has any revealing insights for me?
p.s. rather gobsmacked to find no gaskets between exhaust fannymould and turbo, turbo outlet and exhaust downpipe and turbo and turbine housing and its outlet elbow, is this normal (for Punto JTD)?

 

[a1ant]

Hi

From your description of the smoke and the traces of oil in the pipes I wouldn't be suspecting an oil leak/ problem. You will struggle to find a JTD that doesnt have the breather and boost pipes coated in oil.

From the description of your smoke (black/grey) it suggests to me an over fueling problem (conversely lack of air). The most common cause of this in the JTD is split boost pipes. The normal culprit is the corrugated rubber boost pipe that hes from the turbo to the inter cooler. I know you say you have checked this, but often its hard to see the split when the pipe isnt pressurised under boost unless inspected very carefully.

Also, a split in the intercooler, or the boost pipe from the intercooler to the inlet manifold are also places to check. The pipe that goes from the inlet manifold to the intercooler can sometimes rub on the top of the gearbox, meaning you get a hole underneath that cant be seen easily when looking.

Any loss of air AFTER the MAF and before the MAP can cause confusion and incorrect fuel metering and as a result, black smoke.

Is the smoke screen constant whilst accelerating, or do you get a large puff of black smoke when flooring it followed by it clearing slightly?

Any smoke on startup?

Any strange noises when under boost?

Do you have access to any diagnostic equipment? As although there is no EML, there are a few other places you can check by looking at live data.

A quick test to check that the MAF isnt providing incorrect values is to simply disconnect it and go for a drive and see if there is any improvement. (unlikely but worth checking)

Alan

 

[Brendan W]

:yeahthat:
Air leaks on the delivery side from the turbo or split intercooler would be first on my list. Check around the hoses and i/c for signs of oil escaping.

 

[Crowmark71]

I've had a further look today and think that your conclusions are correct ref laqck of boost, but I think it's being caused by a sluggish turbo (possibly) as it was sticky to turn by hand and after a few revolutions bound up rather more. As an experiment I fkushed the bearing with WD40 and it freed off a lot, but speaking to a guy at a turbo specialist he said this is the equivalent of changing the oil, it'll be OK for a bit then get worse again. It was never intended as a fix, only to see if it helped, so I think Fast Turbo in Corby will be receiving a call tomorrow ordering a fresh spinner/blower.
I will, however, take the opportunity to check all of the hoses and the intercooler for splits/cracks etc, plus I will check the (slightly) abraded section of the compressor-to-intercooler hose where it's been rubbing on the plastic undertray and will replace if suspicious.
Incidentally, the turbo for this car, the IHI VL20, is apparrently not easy to get, or at least spares aren't. as more than one turbo supplier said they couldn''t get bits for them any more. It's a shame I'mso skint otherwise I'd have a cracking excuse to use on Mrs Browser for a turbo upgrade

 

[Crowmark71]

Update; Fresh turbo arrived today, old one didn't really like spinning by hand so removed turbine housing and compressor volute thinking one/both wheels might be binding on the casing, still no joy and actually worsened when turned for a while. Spoke to Fast Turbo in Corby (www.fastturbo.co.uk 01536 601020, good lads) who suggested contaminated oil had damaged the bearings so replacement ordered.
I would now like to nominate myself for muppet of the year award :vollkommenauf: When I took the old unit out I was perturbed to find no gasket in either the exhaust manifold-to-turbine inlet, turbine outlet-to-outlet-elbow or outlet elbow-to-exhaust downpipe joints, but somehow managed to convince myself, as this is the first turbodiesel I've ever worked on (and first engine for quite a while), that this must be how 'they build them these days'
Gasket set now on order from Ebay for £19 as Fast Turbo didn't have one in stock, estimated arrival date Tuesday. Do I feel like a tit? Yes! Did I know it was like that? No! Have I learned from this? YES!!!!!!!

 

[Brendan W]

Join the queue. Don't get your hopes up. There are many talented contenders with star quality and years of experience in this type of competition, myself included. There is always next year.