Overboosting Turbo

[Jay]

I have a low mile (40,000) 06 1.9TDi Audi A4 that is "overboosting the engine slightly" (I had it looked at by Audi due to issues with blocked injectors and me doing sub 2 mile trips every day!). I get this serviced every year on the dot but I have found that the overboost seems to be noticable. I have a friend who has a 1.9TDi same year A3 and he says that my A4 is rapid when put up to his A3. We put this to the test any my A4 is actually quite a bit faster than his A3 for 0 to hmmm 70 shall we say.

now at the moment I am sure its well within tollarance but why would this be and is there anything I should look out for?

[Tonka777]

Split vacuum hose(s), or dodgy manifold pressure sensor maybe?

[Jay]

Split vacuum hose(s), or dodgy manifold pressure sensor maybe?

no, they have done afull test of my car and had a look and there is nothing actually wrong. Could it have come from Audi like this?

[Tonka777]

Could it have come from Audi like this?

Its possible i guess, maybe you just got lucky and got some better parts in yours, unless someone has purposely altered the boost actuator!

If the car is running well, and not blowing gaskets or chucking con-rods out the side every thousand miles, i would say it's nothing to worry about. - Except maybe insurance. Might it be classed as modified now?

[MadduckUK]

unfortunately you are already dead, the next time you accelerate a stream of superheated gas will flash through the car, sending it spiraling across the channel into Dunkerque.

to restart, please turn to page http://forums.hexus.net/hexus-automotive-cars-bikes/

[Jay]

unfortunately you are already dead, the next time you accelerate a stream of superheated gas will flash through the car, sending it spiraling across the channel into Dunkerque.

to restart, please turn to page http://forums.hexus.net/hexus-automotive-cars-bikes/

lol

I have already put a request in to have this moved.

I have been wondering how you have twice as many posts as me in almost the same amount of time, now I know why!

[kalniel]

now at the moment I am sure its well within tollarance but why would this be and is there anything I should look out for?

On that engine, no - it's pretty solid. Usual things are to keep the oil changes frequent and high quality, let the turbo cool down before switching off, go easy on the revs on pull away to reduce clutch wear etc.

Regarding differences to the A3, I don't know if the clutch for the two cars is the same, but the 2.0tdi A3 has had a software update to reduce torque in first gear due to high clutch wear, maybe the 1.9 had the same? The engine is also mounted longitudinally in the A4 vs transversally in the A3 but I doubt this would affect output (longitudinally mounted engines have a weak oil pump axle, but again I don't think this affects the 1.9tdi).

Finally, some MYs the A4 is a bit lighter than the same year's A3

[badass]

Monor overboosting should be harmless TBH. It may reduce the life of the turbo and maybe your clutch but as long as it is slight you'll not notice the difference, reliability wise. However if your car is significantly faster than it should be, it's probably overboosting a lot. This just increases the likelihood of premature turbo failure and stress on the clutch. IIRC the gearboxes are bulletproof so they aren't a concern.
What's most likely to screw up your engine however is your sub 2 mile journeys.
Either get a bicycle or prepare to spend lots of money getting your engine sorted!

[Jay]

Yes the 2 milers are going to cause issues. It nearly failed it MOT on emmisions last year! I try and give it a long run on the motorway once a week to give it some propper running.

[1stRaven]

A few of the volvos I owned have an 'overboost' facility which is mainly the car boosting to a maximum pressure (say 1 bar) and then reducing the boost pressure if knock is detected.

As they say though - Boost is good.