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Discussion Starter #1
I've been trawling for around a month, both here and everywhere else on the net.

Finally got a mechanic to check out it out, aside from a very small amount of oil leaking from turbo, nothing else detectable. No errors, nothing obviously wrong. Likely because of the intermittent nature.

Imagine a car with a poor remap done, the kind of smoking you'd expect would be close to what I'm seeing.


2006 147 JTD 130k ish
  • Intermittent smoking
    • Sometimes constant, sometimes a faint puff.
      • When constant it's not as thick as a burst intercooler hose, but its enough to make people back way off on the motorway
  • Mostly black, occasionally white (raw diesel?)
    • When smoking, power feels down a little bit and sometimes throttle/acceleration feels jerky/stuttery or so hesitant it's refusing to budge, you either shift up and bypass or flat to the mat and get through it.
      • The constant smoke seems to stop if I ease off the pedal to about 5-10% throttle, this is usually enough for cruising, difficult to accelerate like that.
  • Regardless of smoking or not, engine sounds/feels rough
  • Rev range it occurs in is from around 1400 and up.
  • Engine has developed an eerie resonance when it's warmed up, speed related, not rev.(could be unrelated)
  • When I replaced the EGR, I noticed the coolant was down, I topped it up, doesn't seem to have dropped since. If it's leaking, its imperceptible.

Things I've done/had done
  • New EGR (oddly, smoke is occasionally white after this was added
  • pipes/tubes/hoses checked, no splits
  • Timing/Aux belts, water pump done
  • Breather to oil separator was loose-tightened up good n proper
no changes.


I'm at a point where I kind of have to give up. It's only a matter of time before the fuzz see it smoking badly and If it needs an engine rebuild, that's quite difficult to get done here, not just because of the rarity of finding good labour that won't require a kidney or two, but the time involved I can't afford either. Also impossible to justify it on my wee 147. So I might have to ...buy another car :cringe:


Any thoughts on what to test or narrow down.
 

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There are others more experienced than I am when it comes to the dark side but there are always things to check out first:

1. Have you sprayed the engine boost components with washing up/bubble bath solution to test for boost leaks?

2. The small vacuum hoses to the solenoid valve and then to the turbo itself (check these with a Mity-Vac pump gauge) should be tested. As they are cheap, if there is any doubt, change them.

3. Clean the boost sensor. Checking actual boost values with a gauge and comparing with what the ECU calculates may be worthwhile but as often as not, it can be the turbo vanes themselves which are sticky and can be slow to react to how the ECU commands the solenoid valve to control the turbo vanes. It may be possible to work out if it is how the boost is controlled by looking at live data on a diagnostic tools such as MES (with laptop and cables) and visually noting how the actuator rod moves in relation to ECU commands. Alternatively, disconnect the actuator mounting and ensure it moves freely when not anchored to the turbo. Another way may be the ECU measured boost values increase more slowly than the desired boost values.


4. Does it have the added complication of swirl flaps? Have you looked thoroughly? (under inlet manifold)

5. Have you measured the maximum MAF values diagnostically?

Once all that has been done then it is time to start looking at more obscure things but it should be a good starting point.
 

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Discussion Starter #3
Sorry I didn't reply sooner, but I wanted to have something decent to respond with.

1. Still need to do this. Weird smell through aircon after about 20 minutes of driving. Not strong exhaust, so it could be just the oil vapour getting out of the separator. Gonna try and replace this myself at the weekend.

2/3. Can this be done without lifting the car? I have plenty of silicone vac hose lying around, but getting at the right area when all I see are rubber hoses which I'm afraid to remove in case something important starts leaking out.

4. Hard to tell. It's definitely alloy so at least a small blessing, I'll try and get my phone behind the intake to see if theres a slidey bar thing.

5. Trying to get a laptop to get the data.

So yea, I just felt bad not responding, but I didn't yet have anything substantial to add.


The smoking seems to have eased quite a bit. I've replaced the upper turbo pipe which was cracking a bit, but didn't seem busted yet, but it needed done. Upper pipe and throttle body where caked in mucky oil. I'm a little afraid to look deeper into the airbox etc.

Some threads suggested some oil is normal/expected. I'm thinking now that my overfilling the oil (by about a centimetre above max) has caused this, in conjunction with a failing/failed separator the engine could be pushing oil passed the seals and it was getting blown around the whole system. The intercooler is likely gunked up, I'll have to see if I can get it off to clean it.

Still a fair bit of homework to do, cheers for the pointers.
 

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The top turbo pipe cracks in those cracks it is very hard to c, the bottom pipe blows up when it starts going so u would not c any cracks but it will leak at the clamps, if it is the top pipe from inter cooler to throttle body u will hear a sucking sound
 

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It´s ok to take time.
I don't think the engine oil separator is normally a fault. Normally the seals in the turbo weep a little. Overfilling the engine oil should not really have an effect on this.

The small capillary hose from the vacuum pump to the solenoid (think it is front of the gearbox) and on to the turbo is often to blame. Any puffs of smoke can be due to the turbo vane actuator becoming sticky. Disconnect/displace the turbo actuator and see if the lever moves the turbo nozzle freely. That is often a cause of smoke for a second when opening the throttle. If you are not sure exactly what engine you have, the engine code on the landing panel (where the bonnet catch locks on to) may help. If you have the alloy inlet manifold, the chance of having metal swirl valves is reduced. I think I read of a member's car which had an alloy manifold and alloy swirl flaps. The date of car registration may help but there are also ways to obtain a build date online.

To get MAF values, simply record the idle value (should be around 15kg/hr) and at full throttle, say 4000rpm, it should record something like 600kg/hr. You may need an assistant to see or simply record a data log and review it afterwards. You do need to do acceleration runs to get an accurate reading though. It may take 2 or 3 runs to see a good peak figure though.

The foamy detergent solution way to check for hose air leaks can be done when car is not moving but given short sharp stabs on the throttle pedal to allow boost to build up. Be careful not to over-rev the engine but allow it to reach around 4000rpm. Brake cleaner is the thing to use to clean the boost sensor. You can also check the boost sensor values diagnostically via laptop and MES. Again, log values at natural idle and full throttle acceleration.

None of what is mention needs the car to be raised to check from underneath.
 
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