White exhaust smoke
 

Rover 75 05 CDTI 115271 miles.


Oil/water OK, neither ever need topping up between servicing it, no warning lights, EGR blocked off years ago, inlet manifold de-coked at the same time, crankcase breather got a re-furb at the same time.



I had a problem with this when cold about 18 months ago with a noticeable misfire at 1500 - 3000 RPM when in neutral, off load, which reduced to be almost invisible as it got to normal running temp, but the unburnt fuel smell was still apparent, it's doing the same again but may be producing a bit more smoke this time.



Always started instantly, as now, at whatever the temp, sweet as a nut and drove/drives well under power OK.


I did the injector leak test, one was quite noticeable, one other a little high, the other two in spec, so out they came and a set of genuine Bosch injectors fitted, everything then OK and back to normal till now.


I know the chance of a new rogue injector is low but in the next day or two I'll do a leak test, no smell of fuel in the oil.



So a bit of brain picking for when I get the bonnet up for the leak test as to what else could contribute to the smoke, FPR problem ?


Thanks for reading. :}

If it still smokes and stinks of diesel it could be a bad injector still.

Might be worth running a compression test too, a bad injector can cause damage internally to the engine if over fuelling a lot, I've seen pistons melted due to injectors failing and injecting too much fuel.

It isn't common for head gasket failure, but that could also be a cause if compression is low.

Hi Bill.
When was your fuel filter last changed, and did you use a good fuel filter such has the one below.
https://www.ebay.co.uk/itm/285582119374

does this happen in the warmer weather.

Hi Jamie, thanks, the injectors are brand new Bosh but yes one may be faulty so I'll be doing a leak test in a day or two and may do a comp test at the same time.


It has only covered a low mileage possibly a couple of hundred or so whilst doing this and there is no sign of derv in the oil so I don't expect bore wash to be a problem.


As you say, head gasket could be a problem, though rare and it runs perfectly with no loss of performance.


I'll update with what I find, cheers Bill

Hi Arctic thanks for the reply, yes I always use quality filters, changed every year, I wouldn't normally service it till about May, but whilst the bonnets up doing the leak test, I'll give it an early treat anyway.


When it originally happened it appeared in early spring which led up to me doing the leak test, finding one faulty and replacing all four, it's been OK since then, flew through its MOT about three months ago and has just started within possibly the last week or two, I can't say exactly when, it's only when I noticed it in the wing mirror when reversing.



It only happens at an engine cold start, first thing in the morning or at any time during the day and doesn't appear to be ambient temperature dependent, as I mentioned, as the engine warms up, possibly 5-10+ minutes driving it gradually reduces and almost disappears.


I also let it idle till it came up to temp, which takes longer than when driving and the same happens, it reduces as engine temp increases.


On a hot start, just a small hardly noticeable wisp.


I'll keep you updated on what I find.


Cheers, Bill

Hi Bill.
Depending on how much you use the car it could be condensation build up in the exhaust it certainly does not seem much to be to worried about, the FL1 has the same problem quite a few have reported it during the colder months.

I did have it with my FL1 a little changed out the glow plugs, which cured it.

Hi all, just a quick update.


I did several leak test on the ' new ' injectors and they give constant quantities as follows, hot or cold, all 3 mins at idle.


I measured the quantities by both weight and volume as a double check.


1) 15ml
2) 16ml
3) 17ml
4) 16ml
3 is slightly suspect but nothing like the original faulty injector.


Air filter is OK, I changed the fuel filter, though it didn't need it and opened it up to check for metallic particles, not a one !


LP & HP fuel pressures are spot on at the specified rev ranges.


Due to the slight misfire, more apparent and felt at 1500 rpm - 2000 rpm when cold, though it isn't apparent over 2000 rpm and when it's warmed up, I popped Toaf on this new laptop running windows 11 to check for cylinder balance to narrow things down a bit, but it doesn't appear to work properly, I'll re-download it when I get a chance.


Not much further forward at the moment, so the next job is to substitute No 3 injector with one of the good old ones and whilst the manifold is off ( it isn't coked up by the way ) pop the heater plugs out and do a compression test.


I'll post the results.

No I don't get it from the same place every time, wherever I am and the gauge reads 1/4 I brim it.


In fact, since the problem started to show it will have been brimmed at three different garage.


At home, locally, I use one of two garages, one of my sons uses the same ones for his derv and has no problems.


Thanks for the idea, but it appears to be more than the quality of fuel.

Just to point out that a leak-back test is just one aspect of the injector's performance. It doesn't test for a poor spray pattern, for instance.