D2 V8 Blowing Smoke

[CJT]

Went up to five rocks yesterday and the car got a fair bit of a workout due to all the deep soft sand.

It is now blowing black smoke, just a little while idleing hardly visible but noticable when driving.

Any ideas, this is the first time in 7 years the car has been worked hard and I did put an engine cleaner in recently.

[BigJon]

Black smoke is due to an overly rich mixture.

This could be caused by a faulty MAF, faulty temp sender, wire fallen off, etc.

Is it running smoothly apart from the smoke?

[CJT]

BigJon,

It does smell a bit rich and I checked with some white paper and there are no deposits etc. coming out the exhaust.

It still runs smoothly, no lose of power, but I have noticed a bit of a shake when stopped at lights etc.

[BigJon]

If there is a bit of a shake at idle, it is possible that it is misfiring on one cylinder. That would account for unburnt fuel going out the back.

It might have a crook plug or plug lead. Even a coil pack could be playing up.

[justinc]

Just had this exact symptom with failed O2 sensors. DO NOT use aftermarket ones, genuine only is the go.
Replace the spark plugs at the same time, and after fitting sensors (An easy task) drive it immediately. The sooty deposits upstream will coat the new sensors slightly and you want to avoid this. Also, if it has been like this for a while, change the engine oil as it will be fuel contaminated.

JC

[CJT]

Thanks for the replies.

I dropped it in to Daniel at Rocky Landrover today to check the computer for any codes, hopefully it is something simple like a sensor as you have mentioned.

I have been about 250km with it blowing smoke getting back home etc.

Can anyone recomend some good leads and plugs for the D2 V8. I am looking at replacing these and would upgrade to better quality over the original spec if possible.

[CJT]

JC,

As you mentioned O2 sensor gone, getting replaced as soon as new ones can get to Rocky and oil will be changed at the same time.

Getting sick of continually fixing it though, it has been repaired almost every week since I bought it for different issues.

[Redslayer]

JC,

As you mentioned O2 sensor gone, getting replaced as soon as new ones can get to Rocky and oil will be changed at the same time.

Getting sick of continually fixing it though, it has been repaired almost every week since I bought it for different issues.

Mate i know this is an old thread but were you getting any fault codes or check engine lights as a result of faulty O2 sensor?? Think one of mine might be gone as symptoms sound similar but i havent had any fault codes or check engine lights come up.

[CJT]

Mate i know this is an old thread but were you getting any fault codes or check engine lights as a result of faulty O2 sensor?? Think one of mine might be gone as symptoms sound similar but i havent had any fault codes or check engine lights come up.

Redslayer,

I do not recall having any warning lights come on the dash. Thinking back on it I did have a loss of power and I recall putting my foot down at a set of lights and could not even see the car behind me through the smoke. It was pretty bad.

The computer I believe was showing bad readings for the MAF and O2 sensors.

I believe I ended up replacing the MAF and all O2 sensors as well as putting in platinum plugs and new leads made for me in Brisbane.

It was a costly exercise but ran extremely well afterwards.

[boofdtl]

Air flow metre

[LRT]

Redslayer, it sounds as though your car is running too rich. There will be fault codes related to the fuel system malfunctioning. Usually, they are as follows:

Engine running too lean:

Fault 26 P0171 Fueling adaption ti Multiplicative Maximum value Exceeded
This fault code means that the fuel system is too lean on bank 1.

Fault 34 P0174 Fueling adaption ti Multiplicative Bank 2 Maximum value Exceeded
This fault code means that the fuel system is too lean on bank 2.

Engine running too rich:

Fault P0172 Fueling adaption Additive Bank 1 Minimum value Not Reached
This fault code means that the fuel system is too rich on bank 1.

Fault P0175 Fueling adaption Additive Bank 2 Minimum value Not Reached
This fault code means that the fuel system is too rich on bank 2.


These are the 02 sensor faults we had occurring, which indicated that the 02 sensor was failing:

Fault 10 P0130: 02 probe probe Pre-Catalyst value not plausible.

Fault 18 P0130: 02 probe probe Pre-Catalyst value not plausible.

However, the 02 sensor was not the fault. The trouble was the MAF sensor.

Our 1999 Discovery II V8 ran lean with the 02 sensor faults, and occasionally with the running-too-rich codes. It also ran rough when cold, but accelerating the engine caused the roughness to disappear.

During this lean time, we could get 1000k’s on a single tank. After replacing the MAF sensor, we only get 500k’s at the most on a single tank.

However, when we replaced the MAF sensor all of these faults, including the 02 sensor faults and the running rough disappeared!

LRT