Black smoke! Help needed??

[flynhigh2007]

2.0L golf sport 124,000kms


Hey guys,


When i bought my car some 20,000km ago i replaced the oxygen sensor as it was stuffing up and black smoke was blowing through the back. Lately on random days the same thing happened twice (about 2 weeks gap), but when my brother hooked it up to the vag program it was coming up as the oxygen sensor again but then it was saying it was fine. So we assumed it was fine and it was a random occurance

Today in the morning it stuffed up again and was blowing black smoke and burning bout 2.8L/hr at neautral at the lights. Later on in the day it was fine again burning 0.9L and no black smoke. My brother thinks theres something wrong with the computer or ecu or the earth might be damaged, meaning that its not sending the right signals to the oxygen sensor hence the bad burning of fuel.

any take on this guys? Is it an electronics problem?
cheers

[flynhigh2007]

any take guys?

[h100vw]

Most likely electrical. HAve a GOOD look at the wiring above and on the probe. It could be rubbed through and shorting to earth.

Gavin

[flynhigh2007]

ill take a look t it today when my brother gets back home. im guessing if its shorting the earth, the sensor isnt getting the right signals and the mixtures are stuffing up?

[flynhigh2007]

does anyone know any people who specialise in volkswagen electronics?

[flynhigh2007]

we hooked it up to vag-com just now and its coming back as oxygen sensor no signal..

[h100vw]

That's a better description to work off.

That would look to be a duff probe again. I'd be checking for shorts to ground if there's nothing coming out of the probe. As I said in your other thread, have a look at the measuring blocks.

Gavin

[Guest]

Coolant temp sensor

2.0L golf sport 124,000kms


Hey guys,


When i bought my car some 20,000km ago i replaced the oxygen sensor as it was stuffing up and black smoke was blowing through the back. Lately on random days the same thing happened twice (about 2 weeks gap), but when my brother hooked it up to the vag program it was coming up as the oxygen sensor again but then it was saying it was fine. So we assumed it was fine and it was a random occurance

Today in the morning it stuffed up again and was blowing black smoke and burning bout 2.8L/hr at neautral at the lights. Later on in the day it was fine again burning 0.9L and no black smoke. My brother thinks theres something wrong with the computer or ecu or the earth might be damaged, meaning that its not sending the right signals to the oxygen sensor hence the bad burning of fuel.

any take on this guys? Is it an electronics problem?
cheers

It will be your coolant temp sensor out of spec making your car put more fuel in (black smoke) and freaks out the O2 sensor causing a "fault" but CTS is at fault common problem check if you CTS is black in color these fail all the time the new ones should be green but even they fail too

[Mitchy G]

It will be your coolant temp sensor out of spec making your car put more fuel in (black smoke) and freaks out the O2 sensor causing a "fault" but CTS is at fault common problem check if you CTS is black in color these fail all the time the new ones should be green but even they fail too

where is the sensor? im having a similar problem with my car, geting a black watery liquid on the floor and the car is also running rich, id really like to stop this happening as its whenever the car is running not just odd days like in the OP's case.

[flynhigh2007]

More info:


Its a new sensor throwing out an error code P0134,we then cleared the error code and the error comes back even though the measuring block is showing the sensors changing voltages.

[graeme86]

I call coolant sensor or MAF giving incorrect signal to ECU.

[Guest]

CTS position

where is the sensor? im having a similar problem with my car, geting a black watery liquid on the floor and the car is also running rich, id really like to stop this happening as its whenever the car is running not just odd days like in the OP's case.

Its on the LH side of the engine depending on what type engine you have? it is just in the thermostat housing either green or black with a four pin plug on it black watery liquid is a definite sign of a CTS failure Do you have VAG-COM check measured value blocks for engine temp sometimes act erratically

[Guest]

BFQ Engine type

I know that BFQ engines have a software issue where the secondry air pump runs for to long sending extra air down exhaust confusing the O2 sensor thinking its running lean then tells ECU to run rich getting black smoke this is usually only a morning start though!

[Guest]

Hot start

where is the sensor? im having a similar problem with my car, geting a black watery liquid on the floor and the car is also running rich, id really like to stop this happening as its whenever the car is running not just odd days like in the OP's case.

How does your car start on a hot start? takes a while to crank over? They can sometimes cause a hot flood problem too.

[Mitchy G]

How does your car start on a
hot start? takes a while to crank over? They can sometimes cause a hot flood problem too.

Nah mate i don't have the vagcom gear, ill have a look for this sensor, how much will it run me to replace it if it is busted?

and no reguardless of engine temp i get this black liquid coming out of my exhaust the instant i start the car and i have no problem starting the car hot or cold.