Guys, a mate of mine has just bought a mk4 1.9tdi (think it's a 130) anyway, he's driving it back to his house as i type this and the turb keeps cutting out, seems to be when the subwoofer is turned up (but he's not totally sure) Have any of you ever heard of this before? does it sound like a dodgy install? (i'll be removing it all anyway) or is it likely to be somethinga little more serious? the guy he bought it off has apparently had it on trickle charge for a few weeks while he's been waiting to sell it. would a lack of battery power cause the turbo to stop spinning? any help would be much appreciated. cheers. Ryan
New news, my mate has spoken to the guy he bought it off (and he literally bought the car 2 hours ago - still driving home from kent) and the guy reckons that the turbos in 130's are indestructible and totally under stressed so is guaranteeing that it's no the turbos fault. he thinks it's down to engine management or fuelling. he's taking it to a vw dealer tomorrow for a link up to a diagnostic machine to see if that'll help but if any of you have any ideas then let me know. also, do you know of any good independant vw specialists rather than dealers in the newport area? well, we're based in chepstow so between here and there would be cool. thanks guys.
it is not likely to be a turbo problem, more likely to be something that controls the turbo. what is his MPG like and does it smoke?
PS... i bet 50p it is a boost leak. this upsets the computer, which throws all its toys out the prams and says "no boost"
new info, seems to lose power after the second hard hit of acceleration. took it to the local link road and it's ok the first time (100 in 4th - sorry officer!) and then coming back up the road it died at about 70 in 4th. how's the best way to find out if it's a boost leak, maf error or wiring snafu?
im betting on boost leak. the turbo delivers boost. the computer produced a figure for EXPECTED BOOST and a sensor reads ACTUAL BOOST if they are different figures for long enough, it goes to limp mode. hence after a hammer through the gears, you have high boost, high leak, different boost figures and then limp. run your hands over the piping. leaks are easy to spot, it will be leaking dark black oil. aften JUST after the turbo
It could be the turbo, sometimes the variable vanes stick and cause an overboost situation (we saw over well 2.1 bar boost on a Galaxy TDI 115PS once!), then the PCM goes "ohhhh no!" and goes into a limp mode. Thread from at the time... http://www.clubgti.com/forum/showthread.php?t=18901&highlight=variable+vanes If it does it, tell him to drive it without full throttle and I bet it drives fine, but as soon as you use full throttle it will overboost and then go into limp mode. Just stop and turn off the ignition and it'll be ok, until you use full throttle again. But... hopefully it'll just be a maf...
so the computer can be hormonal. if the turbo is a variable geometry item (my pd130 had that) then you can manually move the 'actuator' arm to try unsticking it. they get stuck if its running ill and sooty (smokey) and this cakes the vanes in soot (or crud to be more technical). have fun with that though, the turbo is down by the bulkhead on a golf mk4 right? on the A4 it was just by the OSF wing
