Audi a3 2.0TDI no boost. ?
Good day Yahoo users , i drive a Audi 2.0TDI the car has a boost problem , sometimes it wil boost but only half a boost and above 2800 RPM , thats only if i drove the car until engine is operating temp (90°) switch of for 2 to 3 minutes and start again , i have changed the cam sensor as i had a error on that from VAGCOM still no change , i have checked vacuum pipes , and atmospheric sensor , checked all boost pipes for leaks , the weird thing is i can hear the turbo but there is no boost , normal boost is round about 1700 RPM . Sorry for the gramer or spelling english is not my first language . Any help will be appreciated .
- Robert JLv 73 months agoFavourite answer
Any fault or "stored fault" that's not at the threshold to show an error, even apparently unconnected things like exhaust temperature sensors, DPF back pressure or a faulty glowplug!! can cause an ECU to restrict boost.
If it's a variable flow turbo, check the vacuum pipes to the solenoid valve that controls it, and the operation of the valve itself / its electrical connections.
Also change the engine oil & filter, using a good quality engine flush additive and running it as recommended before draining the old oil.
Some engines have very small passages to feed oil to the turbo and they can easily get clogged, causing bearing problems.
The variable vane mechanism can also start to seize up over time. Using a lubricant-type fuel additive may give some improvement?
I've not had that problem that myself, but a relative who is a car engine specialist says they have seen it a few times & using an additive such as Miller Ecomax can work, if it's not totally seized.
Possibly Marvel Miracle oil or Seafoam etc. may have similar effects.
- CactiJoeLv 63 months ago
May be the Turbo Charger (TC) is starting to die. The bearings inside the TC are a bronze metal type bearing and do wear out over time. The TC spins at around 250K RPM's so there's always a lag in lubrication when you stomp on the gas pedal so the fan shaft and bearings do wear. It could be a failing catalytic converter if you do a lot of city driving, short trips. It would not get hot enough to burn off exhaust waste and start to create back pressure on the exhaust system forward of the catalytic converter. This can be checked by removing one O2 sensor and then stomp on the gas pedal. If the problem seems resolved, then it's not the turbo it's the cat converter.
There was discussion of a class action lawsuit in Australia about the diesel engine catalytic converters plugging up on Asian cars or trucks. They don't call them catalytic converters on diesel engines but they do the same thing.
- Anonymous3 months ago
The turbo is shot. Replace it.