Mkiv Problem! Help!

[dylan8]

iv recently had a few problems with my car going into limp mode, put it down to dodgy fuel and parts on the way out as of the age of my car.

The car had a 3month second hand warrenty on it, in that time i had the MAF replaced, (they were sly and replaced it with a 2nd hand one out of another bora with 20,000km more then mine!!) so its lasted me till now. I had my 115,000km service only a month or so ago, car ran great after for a week or 2, then went into limp mode and after disconnecting the battery and doing 30min+ trips like i was told i cant really get it out of limp mode, took it to have a check up today, had a diagnoistics and was told a new MAF was needed, had that put in, car was taken for a drive, was told it was fine, on hte 15min drive home it seems to have gone into a limp mode again, but not as bad as usual, the car has plenty more power with the new MAF, but not having good fuel economy when running on level ground at a contant speed.

the temperature gauage in the car has recently not been fixed on vertical (forget the temp) like it use to be once warm, its 1/2-1 bar towards cold, and tonight it got as far as 2 bars down. does this have somehting to do with it?

when car is started and left ideling it looks like it blows small and fine smoke clouds then after 30seconds or so stops, but sometimes can produce a bad smell (not quiet burning a burning smell, but along those lines)

Please help! ill be sending the car back for another check up but who knows when ill be able to book in.

Car is a 2001 manual 2lt Bora with 117,000km

Thanks in advance!!

[Jmac]

Ok apart from the usual temp sensor, which is never a bad idea to replace anyway at the price, and of which causes a lot of grief with fuelling. The temp gauge may be true and running cool. The thermostat may be stuck open and keeping the engine cool. This will have an adverse effect on the fuelling too, seen it heaps and changed plenty. See if you can draw some codes, and cool engine will most likely not give a code.
Your smoke issue does sound like the sensor though and may be over fuelling. Anyway check the engine temp while you are there
Cheers
Jmac

[dylan8]

Ok apart from the usual temp sensor, which is never a bad idea to replace anyway at the price, and of which causes a lot of grief with fuelling. The temp gauge may be true and running cool. The thermostat may be stuck open and keeping the engine cool. This will have an adverse effect on the fuelling too, seen it heaps and changed plenty. See if you can draw some codes, and cool engine will most likely not give a code.
Your smoke issue does sound like the sensor though and may be over fuelling. Anyway check the engine temp while you are there
Cheers
Jmac

Thanks Jmac!!
The temp guage does move, and seems to be true (when the cars cold its low and after 5-10mins of driving its at mid way (or in this case, just below)
How much would i be looking at for a new temp sensor?

[william]

The temp sensor as jmac said is a good place to start at only $60 i would charge it anyway. you basically need to run the tank down and let us know in a day or two if its changed also get someone to scan it and let us know the codes

as these are the possibilities

o2 sensor $120
temp sensor $60
airflow metre $450
catolytic converter $1200
rough quote btw

[william]

btw say trade at the vw parts dept they wont ask for a trade card

[dylan8]

The temp sensor as jmac said is a good place to start at only $60 i would charge it anyway. you basically need to run the tank down and let us know in a day or two if its changed also get someone to scan it and let us know the codes

as these are the possibilities

o2 sensor $120
temp sensor $60
airflow metre $450
catolytic converter $1200
rough quote btw

btw say trade at the vw parts dept they wont ask for a trade card

Thanks William!

o2 sensor was playing up a little, but was told it may jsut be doing that with the dead MAF. Hopefully its just a temp sensor looking at those prices!
Thanks for the advice

[dylan8]

Iv done a few longer trips over the weekend. using a fair bit of the tank of fuel.

Last night i was deso for a few of the boys (3 + me driving) (these guys are all pretty tall and got some muscle so had some fair wieght on board) and was using between 9-10lt per/100km which was less then what i was expecting the way the car had been going, but still more then what id be liking. and today i was between 7-7.5lts on the highway with me + 1 other and some surfing gear on board. The main difference i noticed today was the temperture gauge was sitting only jsut below the vertical or 'normal' running temperture.

I got home and stopped the car for 5mins, then started it up again, it below some drops of liquid/fluid out the back, and smelt again. but then stopped both smelling and nothing came out the exhaust.

other then that, when only just touching the accelerator pedal to go up hills or going from 80km to 100km/h zones etc it seems to use alot of fuel compared to what i remember before it all went pear shape...

Does that sound like the temp senor like you guys have said perviously?

Ill try and get a scan run on it over the next few days and see what feed back i get.

Thanks again

[dylan8]

New temp sensor went in (william you were right on the mark with the price, $40 for the part, fitting, gst etc and came to $60!)

Drove out of the yard and it was still a bit high on the fuel usage, and the temp guage didnt seem to be much better.

Got home, disconnected the battery for 15mins+, reconnected, went for a 30min+ drive (gentle highway km for hte first 25mins or so, then from a standing start up a hill to 100km/h giving it abit)

result: temp gauage is almost correct, can drop half a bar towards cold sometimes. fuel perfect! 7lt per 100km at 100km/h, 5lt per 100km at 60km/h.
No smell or excess out of the exhaust.

Big thanks to jmac and william!!