Lack of power

[twosox]

Hello everyone, this is the first time I have posted a thread but I have been reading a lot about problems with a lack of power. I have a 1998 Passat TDi with 80000 miles and an auto gearbox. The car has been superb for all its life but a month ago whilst overtaking a truck, the car just died on me. I was travelling at about 60 mph. I changed the mass air meter and this seemed to sort the problem but unfortunatley the fault was back within the week. I took the part back to the shop and got a replacement and at first it seemed to sort it out again but within an hour the problem was back. The odd thing is that the fault is intermittent. One moment the car is great and then for no apparent reason I can fathom it just goes 'FLAT'. The problem is worse when I have attempted to accelerate from around 50/60 mph but not from lower speeds. All vacuum pipes are okay and there is no blockage in the EGR valve pipe. Wiring looks to be in good condition also. I've also changed fuel filter but to no avail. Any suggestions would be most appreciated. Anyone have any ideas? Regards, Twosox.

P.S. Local VW dealers want loads of dosh just to open the bonnet so they are not an option at the moment.

[adamss24]

Hello everyone, this is the first time I have posted a thread but I have been reading a lot about problems with a lack of power. I have a 1998 Passat TDi with 80000 miles and an auto gearbox. The car has been superb for all its life but a month ago whilst overtaking a truck, the car just died on me. I was travelling at about 60 mph. I changed the mass air meter and this seemed to sort the problem but unfortunatley the fault was back within the week. I took the part back to the shop and got a replacement and at first it seemed to sort it out again but within an hour the problem was back. The odd thing is that the fault is intermittent. One moment the car is great and then for no apparent reason I can fathom it just goes 'FLAT'. The problem is worse when I have attempted to accelerate from around 50/60 mph but not from lower speeds. All vacuum pipes are okay and there is no blockage in the EGR valve pipe. Wiring looks to be in good condition also. I've also changed fuel filter but to no avail. Any suggestions would be most appreciated. Anyone have any ideas? Regards, Twosox.

P.S. Local VW dealers want loads of dosh just to open the bonnet so they are not an option at the moment.

Hi, go somwhere where you can have the car scaned for fault codes...i think your airmass meter is Ok but you may get a overboost code and ECU doesnt like it and it puts the car in Limpmode to protect the engine. You may need to turn the ignition off and on again for it to clear. The reason for a over boost is you dont drive your car hard enough ! I know it sounds silly but your turbo is a VNT one has some moving vanes that stick when soot and carbon builds up. With diagnostic equipment(Vag-com) you can turn on and off the VNT controler and see if its mooving smoothly. Take the engine cover off and look at the turbocharger For a round actuator with a metal rod stiking out of it and where the small vacuum tube goes to and try to move back and forth with your hand. If its stuck, then you may need to remove the turbo and soak the VNT macanism/vanes in some carb cleaner to remove the gunk ! If you are good with the spaners you could try to open the turbocharger up, the cast iron side by removing the 8 or so bolts paying atention how the thing bolts back again and clean well inside. Its no rocket science but its quite fidlly ! Remember to give some stick to your car once a day and few times a week because its good for the turbocharger and also keeps the intake and the intercooler clean. Shift every day few times at 3000 rpm and at least once at 4000 rpm, works the vanes/turbo especially if you stay a lot in trafic or car idles regularly. Keep us updated if that sorts the problem. While you do the turbo you may wanna clean the intake/EGR valve while you are there. Also check the N75-so called the vacuum controler valve, check if it holds vaccuum. Good luck.

[twosox]

Hi, go somwhere where you can have the car scaned for fault codes...i think your airmass meter is Ok but you may get a overboost code and ECU doesnt like it and it puts the car in Limpmode to protect the engine. You may need to turn the ignition off and on again for it to clear. The reason for a over boost is you dont drive your car hard enough ! I know it sounds silly but your turbo is a VNT one has some moving vanes that stick when soot and carbon builds up. With diagnostic equipment(Vag-com) you can turn on and off the VNT controler and see if its mooving smoothly. Take the engine cover off and look at the turbocharger For a round actuator with a metal rod stiking out of it and where the small vacuum tube goes to and try to move back and forth with your hand. If its stuck, then you may need to remove the turbo and soak the VNT macanism/vanes in some carb cleaner to remove the gunk ! If you are good with the spaners you could try to open the turbocharger up, the cast iron side by removing the 8 or so bolts paying atention how the thing bolts back again and clean well inside. Its no rocket science but its quite fidlly ! Remember to give some stick to your car once a day and few times a week because its good for the turbocharger and also keeps the intake and the intercooler clean. Shift every day few times at 3000 rpm and at least once at 4000 rpm, works the vanes/turbo especially if you stay a lot in trafic or car idles regularly. Keep us updated if that sorts the problem. While you do the turbo you may wanna clean the intake/EGR valve while you are there. Also check the N75-so called the vacuum controler valve, check if it holds vaccuum. Good luck.

Hello Adamss24. You more or less got my driving mode bang on when you said I don't drive the car hard enough. Anyway I had a good look at my Volky and found the round actuator with the piston you mentioned. I got some one to press the accelerator for me and the piston appeared to work okay but only at the lower revs. As soon as 3200 revs were hit it just stuck and just as you suggested, I had to turn the ignition off in order for the car to then come out of 'limpmode'. I sprayed the metal piston with WD40 and got it moving and it now moves freely through the full revs range. I have blasted the motor up the M62 at aroung the 4000 revs mark for a good few miles and since I have done this I have travelled about a 100 miles giving the car a good blast. I am more than just pleased with the results because it has completely transformed how the car drives. It is quick and torquey again just like it used to be. I am going to take a bit more time when I finish my shift rota this week and clean all the bits you suggested but I am really over the moon now. It just leaves me to say a big thank you for taking the time to help me out, SO MANY MANY THANKS I am indebted to you. Regards, Twosox.

[Gaz the Cab]

Interestingly I was having a conversation on similar lines with the local indie this morning.......his recommendation (remember mine is used as a cab) is a once a week blast "in 4th gear at 100mph", not quite sure about the speed but the sentiment will be acted on but using 3rd gear instead

[twosox]

Hi Gazthecab. Seems good advice considering the stuff I got from Adamss24, another forum member. My motor is like a different thing altogether now. I normally just use it to get to school and back through traffic (14 mile round trip) with an occassional trip up to Scotland. It's on a motorway hop and the added speed that my 'lack of power' problem used to show up. Thanks to Adamss24 I have understood the cause and been able to sort it and your input seems to confirm the problems root cause. Because it's a 4 speed auto I plan to boot it up the M62 once a week holding it in 3rd gear. This should keep everything clog free and working properly. Anyway nice to hear from you and thanks for your reply to my problem, Twosox.

[fahad]

hello
if you people having porblems with the power it will definetly will be the e.g.r valves in a vw passat 1.9 tdi and 100% right.

[adamss24]

Fahad, EGR valve stays open only at tick-over to keep NOX (nitrogen oxides) emmisions down. As soon as you place some load on the engine it turns off. There are so many differet symptoms on a TDI engine and with apparently the same causes(sometimes different cause= same effect...!) If the EGR valve blocks open (due to gunk/soot build up on the exhaust !) then it may cause lack of power and poor performance overal but dont forget it is vacuum/electrical controlated so it will set a code in the memory.

[fahad]

hi gays all of you have to clean up the erg valves after 50,000 miles. the full unti as to open and closes.

[fahad]

hi
i have a passat with the same problem that will NOT rise over 50/60 mph what will the problem be in the car can you people help me. i have change the MAF . plz help
It a Big Problem to all of use!!!!!!!!!!! so try to clean the Throttle Body