Smoking exhaust, needs cleaning out, how?

Take it for a minimum 2hr drive, at c60mph.

it needs heat, and to heat it right through takes time.

Can you force a DPF regen. That should heat everything up nicely..

it doesnt have a DPF.
Its done >100miles since rebuilding,, did 25miles yesterday at 3500rpm, mostly
To get the heat, does it have to stay at high revs for a long time, or keep it under load continuously(accelerate up a big hill all day)?

To get the heat, does it have to stay at high revs for a long time, or keep it under load continuously(accelerate up a big hill all day)?

The wider open the throttle, the more exhaust will flow and the hotter it will get. Ideal thing would be towing a heavy trailer up a steep hill in first gear.

Keep it above 50, it’ll get hot enough regardless of how you drive it, the important thing is to do it for long enough.
if it takes , say, 10 minutes for the temp gauge to be at normal, it’ll be double that for the bottom of the engine to be at normal, and then double that again to warm the gearbox right through. S0 40 mins.

So who can lend me a heavy trailer, and a steep hill?

So who can lend me a heavy trailer, and a steep hill?

You can take my boat to N Wales for me at the weekend - by the time it's loaded with 350L of fuel it will weigh about 2000kg!!

Is the exhaust exposed  and easy to access?  Maybe try heating with blow torch to burn off the remaining oil?

Go for a day out somewhere that involves say an hour+ drive each way... I'd imagine that would probably sort it out.

You want to not only get the exhaust hot, but keep it hot long enough to burn off any residual.

Unless you've got an MOT coming up just drive it as normal and it'll gradually go. It really makes no difference to emissions, you're evaporating the same amount of oil just over a longer period and without the extra driving and higher revving to accomplish the same thing a bit quicker.

Park it facing downhill on a steep hill so oil flows back towards the hotter parts of the exhaust?

Was going to suggest the reverse so you end up with a puddle of oil under the exhaust tip but you'd need a *very* steep hill.

Italian Tune Up

Intercooler probably full of oil if you turbo seals blew.

Whip it out and wash it in petrol, then hot water.

Will smoke for a long time if ots clogged.

<p style="text-align: left;">Clogged with what ?</p>
I mean surely no one that's replacing a turbo hasn't already cleaned the intercooler -its 101 to clean the intercooler in such a situation.

As above, revs and heat. I just took mine out at night for a few thrashes. It took a surprisingly long time to stop, the crossover between "gets hot enough to smoke" and "doesn't get hot enough to burn off quickly" was pretty big.

the intercooler itself .hasnt been touched
its now been for a 50mile run at 60-70 and over 3000rpm

if its slightly overfilled with oil, would that affect it in this way?

I mean surely no one that’s replacing a turbo hasn’t already cleaned the intercooler -its 101 to clean the intercooler in such a situation.

You might think that.

In this case, not been touched.

Clogged with what?

Dutch wooden clogs., various sizes from 7 to 9, some left, but a surprise amount of right footed ones.

Or its clogged with air, the really thick, dense heavy version of air.

Thats 300 miles at a good pace now, still smoking on idle.
If there was an intercooler problem, would that only affect things when the turbo is active?
The car did not smoke before, that i noticed, so what else can it be?
If the engine was overfilled with oil before, would that force oil through valve stem oil seals and out through the exhaust? and if it did, would the valve stem oil seals be damaged, so it would continue to happen?
Do i need a compression test?
Its done >160k miles
its done my head in too. Im leaving it alone till next week

What colour is the smoke?

Clogged with what?

Dutch wooden clogs., various sizes from 7 to 9, some left, but a surprise amount of right footed ones.

Or its clogged with air, the really thick, dense heavy version of air.

So you have no idea if you just say that next time thanks

<p style="text-align: left;">If there was an intercooler problem, would that only affect things when the turbo is active?
The car did not smoke before, that i noticed, so what else can it be</p>

If not from the 1980s the turbos always active In some form.

If the intercoolers full of oil (but not blocked - as that would manifest considerably more issues than smoking )  then it'll be feeding oil contaminated charged air to the engine and onwards to the exhaust

As I said after a failed turbo it's absolute 101 to pull the pipework and intercooler to clean so that's where id be going if as you say it's not been done.

Surprised no-one has suggested the obvious...

That only works on de-catted imprezas.

If there was a build up of oil in the intercooler, then you would have known about it quite quickly, as the first time there was enough air flow to suck the oil in, the engine would have runaway as it ran on the oil.

Was the only symptom of the turbo failing oil in the exhaust?
Or was there other issues like loss of power?

If the engine isn't burning any oil, then it is likely just a build up of oil in the exhaust, which can take a very long time to burn off without any other intervention.
If you're really concerned about, taking the exhaust off and pressure washing it will help. By now it's probably only the rear silencer that's likely to still have oil in it. Easier option could be to just stick a power washer up the tail pipe.
Only thing to be aware off if you do wash the exhaust, is it will result in a lot of water vapour/steam as it dries out. You ideally want to do it where nobody will complain about clouds of smoke/vapour being produced.

I know what it is probably clogged up with. You know  what it is probably clogged up with. Yet you still felt the need to ask me to clarify what I thought it would be clogged up with. Then you bought a keyboard with no punctuation keys ,  to belittle me with a rubbish one liner pertaining that I know zero about the inner workings of a chra.

its a major operation (for me) to remove the intercooler, and people i spoke to didnt deem it necessary.
There was a loss of power, and something had gone into the turbo and bent the fins
so i got a new chra

At this point, cleaning the intercooler isn't going to help.

It being blocked is highly unlikely, as it would take more than a few bits from a turbo to block an intercooler to the point it affected performance.

Also given the mileage travelled, anything that was going to make it's way through the intercooler and into the engine, will now be embedded in the engine or out the exhaust.

The smoke is either residual oil still in the exhaust, or the turbo failing has caused internal engine damage and the engine is burning oil. Which is why I asked whether the engine is burning oil.

the oil level is pretty constant.
The smoke does smell of oil, and is grey/black, and coolant level is the same.
I'll take the exhaust off for a pressure wash

The smoke should be blue if it is oil burning.

Yeah black is running rich.

Did you get a warranty on the turbo work?

If the smoke is grey/black as you say, it's more than likely a fueling issue. IIRC I had the same issue when I changed the turbo on my VW caddy 1.9tdi in 2015. I had mixed up two of the vacuum hoses when putting it all back together.

My turbo went like a screaming banshee two days after I hit a massive pothole. Two of the turbo impellers (boost, intercooler side) had split, but didn't actually break. I would want to know what wrecked your turbo in the first place. They don't just blow for no reason and it could indicate another problem if a bit of debris has actually ended up hitting the impellers.

supremebean
Free Member

The smoke should be blue if it is oil burning.

Yeah, but in practice this isn't always useful. Can be, but you've got to be pretty brave to diagnose based on colour

Has any one mentioned grenaded intercooler or pipe leakage

im sure i got the vacuum hoses on the right way.
not so sure on the smoke coloue, but its not white.
Dont know exactly what happened with the turbo,was just overtaking a bus when it lost power.
Prior to that i tried mr muscle to clean some carbon out of it

Boost pipe?

Yeah, but in practice this isn’t always useful. Can be, but you’ve got to be pretty brave to diagnose based on colour

Isn't always useful? But it can be?

It's not a diagnosis, it's a starting point towards diagnosis.

Anyway, as molgrips has mentioned, i'd be checking the boost pipes. Get someone to rev the car in neutral and check all the joints. Should be pretty obvious if a connection has gone. The vag boost pipes have a little lug that the circlip locks on to and they can wear away over time, particularly the pipes going in to the intercooler.

Also, does it smoke immediately on a cold start up? Or does it build up with heat?

It used to be the practice to 'de-coke' exhausts on little motorcycles back in the day to slosh petrol down them (off the bike obvs) and then light it.
Not sure it actually achieved anything in real terms but, it was a thing.

I did it once to my little Rxs100, lit it, and the resulting explosion put me backwards onto the floor, luckily still with eyebrows.

Ah, those golden times of flammable liquids and low common sense...

In my experience turbo cars do not 'run on' from the oil in the intercooler.

Mostly its from the pcv system, is contaminated and heavy. It sits in the bottom of the intercooler and the air moves across the oils surface. It does not get picked up and lifted in great quantities. It can make its way through the engine unburnt as it wouldn't be atomised in any way. Also old engine oil has low cetane so not likely to ignite.

Cars that run on usually get new oil from the sump, crank slap from massively overfilled sumps mist the oil. The pcv system blows this into the intake and self combustion occurs.

Knackered thrust bearings would allow more oil from the chra either downstream to the exhaust impeller chamber, or upstream to the intake compressor wheel, and through the system to intercooler, then potentially up the intake tract to the head. However, i have seen 3mm float on a turbo and no oil was getting by.  And have rebuilt turbos with new bearings that still smoked after a refurb.

Back to the op. How much end float was there on the old turbo? Strange its still smoking with a new turbo on it.

My favourite boost pipe check is to wind the window down and find a road with a wall next to it. You can hear the hissing and whining. Or have someone else drive past you as you listen.

The exhaust isnt smoking on cold startup
Booest pipes were fine, i cleaned them.
Not sure how much end float, but more than with the new chra.

I wonder if it's not the catalyst. Have seen smoke with a aftermarket cat not getting up to temp. Problems disappeared immediately after fitting oe cat. But not until the garage guessed it was the turbo and we drpp. dropped a grand on exchanging a perfect turbo trying to get to the bottom of the smoking exhaust.

Just to be clear, are you still driving with the tankful of fuel with the (double dose of?) engine / injector cleaner in it? I wouldn't be surprised if whatever's in that gave you more smoke while you're actually running it.

I'd not worry too much until you've run the tank low and refilled with plain fuel and see if it's any better then.