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Jeep 2.7 crd pulsing black smoke at idle

Old 12-17-2015, 02:06 PM
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Default Jeep 2.7 crd pulsing black smoke at idle

Hello again all,

I hope everyone is well.

I'm hoping you technical gurus can give me some direction as I have recently piled money into my car to help repair it and it is getting worse and worse.

The car recently wouldnt start, it would crank over fine but not start (whether hot or cold). Once the car was started (spraying tiny amount of easy start in the intake) then it ran perfectly: balanced, plenty of power and no smoke apart from a small puff of black smoke on WOT. I took the car to a reputable diesel specialist who identified faulty injectorshaving removed and tested them, saying 2 were leaking too much fuel back to the tank and 1 of them was the wrong injector.

The car now starts fine but immediately once started it pulses black smoke out the back regardless of the car being cold / warm etc, even at the garage when I picked the car up it was doing this. Sometimes it also shakes a bit and feels like it is misfiring but this is intermittent and only at idle.

Also when you press the throttle then a black smoke cloud pours out the back, if you keep the throttle about half way then the black smoke clears but turns into a blue / grey cloud of smoke instead. Sometimes you can try to accelerate and the car doesnt go any faster, it just chucks black smoke cloud out the back.

The mechanic told me to expect this for a week or so after replacing injectors as the fuelling has been incorrect for a while with busted injectors, however, it hasnt improved. After about a week the CEL came on and I took it back to the garage expecting a fuel related issue as I believe he has fubared my car, but instead is was code P0245 (turbo actuator). Ive never had turbo issues in over 3 years of ownership. He said the turbo actuator was sticking, so he freed up the actuator and the CEL is off but the car still creates the trio of smoke clouds as it did before. He said the work he did on the injectors was fine and him changing the injectors has not broken my car, it has just unearthed other issues that were being masked when the injectors were faulty. He said if this smoke issue persists or the CEL comes back for the actuator then I need a new actuator and turbo, he won't recheck his injector work.

I am stuck between this issue being one (or more) of the following:

- problem originated by only replacing 3 of 5 injectors that now arent evenly providing fuel, hence the pulsing black smoke at idle. The black soot being created could as a result be clogging up my turboand causing the CEL for the turbo wastegate actuator?

- turbo is on its way out which may explain blue / grey smoke under load and maybe restricting airflow at idle, causing black smoke? Also the CEL came up with a wastegate actuator issue.

- Possible low compression in some cylinders originally hidden by the injectors in those cylinders not working? The pulsing black smoke and blue smoke could be from blow-by in these cylinders?

I have also done the following checks:

- Taken turbo intake hose off, there is some oil pooling on the compressor face once it has sat but not sure if this has come from the Pressure vent valve that joins back in the intake hose.

- The turbo shaft seems to move side to side by about 0.5mm?

- I also took the air intake hose off between the intercooler and inlet manifold and after a few minutes and gentle revving there was some obvious oil spitting out of it all over the engine bay.

- Taken off oil filler cap and dipstick with engine running, cant feel any pressure or air coming out of it at all which I thought you would if I had low compression / blow by?

- The CEL is not illuminated and no stored fault codes.

Thank you in advance for any suggestions you can offer.

Last edited by tommygards; 12-17-2015 at 02:14 PM.
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Old 12-17-2015, 02:50 PM
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Turboshaft side play is usually normal. 0.5mm is about .020" of play which is well within specs for any turbo and something I'm surprised you'd even pick up. Where is the oil spitting out from when revving? Post intercooler? I'd look into turbo.
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Old 12-17-2015, 03:14 PM
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Hello,

Thanks for the reply.

to be honest it seemed about 0.5mm from wobbling it with my finger, you could see it physically move from side to side. I havnt got a dial to test it with, just did it by eye on my drive. (poor engineering i know).

The oil is spitting out of the intercooler - inlet manifold pipe. If you disconnect the pipe from the throttle body and rev the engine then it can spit oil all over the side of the battery after a few mins, enough to drip down the engine bay and onto the road.

So you think the shaft play is ok but still to look into the turbo?

Thanks again

Last edited by tommygards; 12-17-2015 at 03:17 PM.
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Old 12-17-2015, 07:05 PM
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Is there any crankcase vent tubes going to the intake? Other than that I can't imagine anything else that would blow that much oil through the intake system. And if you're blowing that much oil out the crankcase, there's probably a lot of blowby. Eliminate one of the possibilities, then work from there.
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Old 12-18-2015, 02:15 AM
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thanks very much.

Yeah sorry, the pcv (or pressure crankcase ventilation i think?) comes out the top of the rocker into the intake. I've had that pipe off and it only blows slightly, as well as removing the dipstick tube and oil filler cap and again i cant feel anything. I havnt revved it whilst doing this though, only at idle (obviously because i cant reach whilst revving the engine) but may get someone to help whilst i check this.
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Old 12-18-2015, 05:52 PM
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So a couple of updates...

I've taken the connecting pipes off the turbo and the exit from the compressor, where the pipe goes from the turbo to intercooler, is covered in oil.

I've also taken the pipe off between the pressure crankcase ventilation valve / oil separator. At idle no air comes out of it, but revving it then you get air coming out. Considering it is meant to use the vacuum from the air intake to help pull air through (which was removed) then in guessing even when revving it that no air should be coming out? Not 100% sure what to expect out the pcv then the hose to the air inlet is disconnected.
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Old 12-18-2015, 06:04 PM
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sounds like injector seals to me.

is it going through oil like crazy?
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Old 12-19-2015, 04:15 AM
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It is going through oil, although if the seals had gone then would you not feel pressure in the oil cap? Something else I'll get the garage to check if I have to demand they recheck their diesel work.
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Old 12-19-2015, 06:25 AM
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i know on my f450 when my injector seals went, i was using a lot of oil very rapidly till i was out of oil and smoked like hell, then it just shut down and not start up due to no oil left as the injectors were run on oil pressure.
not sure if the crd runs the same way, does yours run rough when low on oil?
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Old 12-24-2015, 11:17 AM
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Hi all,

So the turbo has been replaced and the blue / grey smoke has now gone when the car is under load. The issue I have remaining now is black smoke at idle and billowing black smoke under load, especially up hills. Sometimes under load is also seems to shudder like the engine is unbalanced. Sometimes you can also hear a 'clunk' in the engine bay (especially when returning the car to idle such as stopping at traffic lights) and the pitch of the engine seems to change.

Could EGR be causing this? If so then shouldnt it throw a fault code if its incorrect or the MAF suitably adjust the fuel at idle to compensate? The only other thing that I think could be causing this is that they screwed up replacing the injectors in the first place, maybe didnt program them correctly if they do need programming.
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