Lower Fuel Economy and Black Smoke at Revs...

Hi all... long time since I've checked in here, but been busy with other projects etc. Hope you're all well...


Over the last 6-12 months or so I've noticed the fuel economy on my TD4 has been a bit worse than it used to be (getting ~380 miles between fill ups, instead of well over 400) and also that it spews out quite a bit of black smoke when accelerating hard. The car is a 2002 TD4 with about 85K on the clock.

I don't just mean a puff of black smoke, and it's not clouds and clouds, but it is definitely more than it used to be.

Any ideas?

Are the two things linked?

Is the EGR mod worth trying.

Try giving it some fuel treatment such as Millers. It increases the cetane rating of your fuel thereby improving the bang in the engine and it cleans your injectors.

sounds like a boost leak to me!

Black smoke suggests over-fuelling, so I'd look into the air inlets first, pipes, air filter, intercooler etc and see if there are any blockages or tears/holes etc that would allow less air to reach combustion.

Dunno about freelander injectos etc, but my Disco has injector leak off pipes ... about 4-6" long small bore pipes that go between each injector and have a fabric outer. After a few years they harden and crack, letting air in which can produce similar symptoms. Try pulling one off, if it comes off cleanly they're possibly OK, mostly they're extremely hard to pull off 'cos they've hardened .. examine them closely at each connection, and have someone rev the engine while you watch them.

ste220 said:

sounds like a boost leak to me!

Click to expand...

Not wanting to be a dummy, but that means what exactly?

split boost hose????

Ok... another dumb question... where's the boost hose?

ShotgunDrew said:

Ok... another dumb question... where's the boost hose?

Click to expand...

turbo-intercooler
intercooler-inlet
any other boost carrying hose

Having a look round t'interweb, I cme across this...

http://www.tuning-diesels.com/75Zt/R75serv.htm#fi

Specifically...
"SOME BLACK SMOKE - NO POWER LOSS, POOR MPG.

1) Maf sensor faulty - they can give out too high a signal rather than the more common loss of signal. This leads to some smoke, sooty marks on the bumper above the tailpipe and below average mpg. Because there is no loss of low down torque, the maf sensor is often overlooked. Many owners have had much improved mpg by fitting a Pierburgh maf with a Mafam MF75p or Synergy.

2) Faulty injector. See comments in previous section."



Any clues??

Black smoke is cool man! Check out the Dodge Ram diesels on youtube lol. You'll be able to smoke the cops out!

Check this: [ame="http://uk.youtube.com/watch?v=JlaxKNeoBXw&NR=1"]YouTube - VIPER VS. DIESEL[/ame]

but on a serious note, your probs on the right tracks, unburnt fuel from a leak somewhere which would explain ur mpg going down. if the smoke coming out ur rear silencer, then it's being burnt in the exhaust, if it's coming out nearer the front of the freebie, it's leaking onto something hot and burning off there most probably.

so... where abouts is ur smoke coming from?

The smoke is exhaust smoke...

that will probs make it easier for u then, ur ecu is probably putting too much fuel through cosa the sensor like said above, if it was a leak then the smoke would probably be coming from somewhere else.

Someone correct me if i'm wrong, but cos the fuels getting to the exhaust, then you can probably rule out a leak.

crewebiker said:

that will probs make it easier for u then, ur ecu is probably putting too much fuel through cosa the sensor like said above, if it was a leak then the smoke would probably be coming from somewhere else.

Someone correct me if i'm wrong, but cos the fuels getting to the exhaust, then you can probably rule out a leak.

Click to expand...

boost leak, NOT fuel leak!

wouldn't he be getting a loss of power if it was a boost leak though?

yup!

Not really noticed any loss of power...

I'm just in the process of trying to change the fuel filter, but can't get the bastad out...

Changed the filter... what a sod of a job that is to do!

When I had a turbo hose split in mine the loss of power wasn't really noticeable until about 75/80. The smoke was though, and the engine management light came on after about 5 miles.

It's probably one of the above that the other guys have suggested, but replace your crankcase breather filter/valve assembly as your symptoms could point to a badly blocked unit.
Yes the EGR bypass is well worth doing on the Td4, but won't solve your current problem unless your EGR is the problem.