Td4 White smoke and misfire.

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Andylandy006

New Member
Posts
6
Location
Bedford
Our td4 2.0 diesel has just failed an mot on emissions. The car has been difficult to start at times usally when cold, the battery has been dying after about a week.
The car produces white smoke on start up and continues. I started it today and filled the street with white smelly smoke.
The garage found the following fault codes
P1df5 - anti theft device signal (ews)
P1613 - engine stability controller
P1e00 - can bus
P0235 - boost pressure sensor fault

Ive scanned it today with my elm code reader and there are no fault codes.
Before the car went for the mot i cleaned out the egr valve, inlet manifold and boost pipes all covered in oily gunk. I think some of the fault codes were from me unplugging sensors to get the inlet off.

The garage wanted to do a compression test but i felt it was more likely to be fuel related or a wiring/ sensor problem.

My knowledge of diesel engines is limited and ive spent the last week trying to research the problem. Any help or advice would be kindly recieved.
 
White smoke is fuel which hasn't burned. So it's likely to be an injector that isn't spraying correctly, or low compression giving insufficient heat to burn the fuel.
 
Second that diagnosis. My 05 TD4 auto had the same symptoms. It was a duff injector or two. I tried unplugging them one at a time and a leak off test but nothing was conclusive. Luckliy I managed to pick up 4 injectors on eBay that had been tested so swapped all four. No smoke at all on start-up and it runs really well.
 
White smoke is fuel which hasn't burned. So it's likely to be an injector that isn't spraying correctly, or low compression giving insufficient heat to burn the fuel.
I have the white smoke issue but no problem with starting... feels a bit 'sluggish' at times, should I be looking at the injectors?
 
my citroen dispatch van had a problem with EGR valve and produced a lot of white smoke the valve had stuck open and exhaust gasses where going back into engine so no new air to breath , showed no fault codes, might be good to block it off and see if better, it might be cleaning it has made it stick, I know the EGR should be working for mot but think it will tell you if that is the problem
 
Also noticed f5 fuse in the engine bay had blown, i think its for the ecu it is a 20a fuse. Not sure if this would effect anything. I had replaced it last week aswell.
 
I did the same thing replaced the egr and cleaned the manifold ect and had the same prob turned out (for me at least) it was the fuel pressure sensor harness
 
Also noticed f5 fuse in the engine bay had blown, i think its for the ecu it is a 20a fuse.
F5 is for the fuel burning heater (FBH), which I think is normally a 10 Amp fuse.
Not sure if this would effect anything.
I just means the FBH is faulty, so won't affect the way the engine runs. No FBH just means slower warm up times, when the outside temperature is below ~5°C.
 
If you quote who you are answering, then the answer makes more sense. ;)
I went off on a bit of a tangent from the original conversation there. Saw FBH comments about exhaust and being faulty, so thought I’d add that. I should have checked the original question first.
 
Coming back to the original white smoke question. I have this at 2-2500 rpm. When I force the turbo to add more air by supplying 12v to the boost control solenoid it is a lot better. I would prefer not to have to make my own boost controller, but I suppose that is an option. Next to check is HP fuel sensor wiring (although voltage of sensor output is now ok - 2v at 3000rpm at the sensor end, so I guess fuel pressure ok and connection probably ok), and about to strip and check boost solenoid. The solenoid seems to need a full 12v to fully engage the turbo actuator, which the ECU never provides it.
What would be very useful is to have some measurements from a non smokey td4:
MAP output voltage at idle and 2000rpm & 2500rpm(to show what boost pressure is normal) - with ECU driving boost solenoid and with solenoid powered with 12v

Any one want to volunteer this information?

I worked out a rough graph of MAP output versus air pressure from the sensor spec sheet (0.25v=3.6psi absolute, 4.75v=36.2psi abs, so the normal atmospheric pressure (14.7psi) giving an output of 1.78v is about right). You can also of course use a scanner, I just found this a bit more convenient and you can use this voltage for a boost gauge.
 
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