Hi All,

Well my T4 now with 150K on the clock used to go like stink and I say stink because it used to put out lots of black smoke. When I first got it, 134K miles it used to put out a bit of black smoke on full throttle at high engine revs, faily normal. This smoke got worse and worse but it really was fast:-) and only did it when you clogged it fine otherwise.

Then one day no smoke and well down on power, thought it might be the MAF so changed that and even tried another just to be sure no luck. Now it is a little intermittant mainly slow but occasionally cuts back in and I get some smoke and more power. I would say it is running at about 40% of its original power so quite useable but no good for overtaking etc

My theory is this ..... could it be the temp sensor ?

Temp sensor started off going out of spec telling the engine it is cold, hence over fuelling -> black smoke and more power. now it has gone completely and the engine is just using a safe preset value all the time and running lean?

Cant see any evidence of a previous owner fitting some dumb resistor in series to 'chip' more like bodge it.

Temperature guage reads OK, is it the same sendor for both guage and ECU ? If the same unit does it have seperate sensors inside ?

And finally temp sensors seem cheap so might be worth a punt anyway, can you tell me where it is ? Mine is a 51 plate 2.5 TDi 102 BHP and also the colour of the wire / wires that go back to teh ECU so I can buzz them out too.

cheers Ben