Boosting too high, But why?

[Lofty86]

It might not be a bad thing, but my furby is boosting @ 1.5bar. (gauge is good as it used to read 1.25, or whatever factory boost is).

I thought it might have been a hole in the downpipe, but took it to a mates, who is a great mechanic, along with my welder. But no holes, or leaks!

So checked all the vaccum control and vacume vessel, which are all fine.

The only thing we can think that would raise the boost is venting the crank to atmosphere, and better oil supply to the turbo (oil change from Skoda's own, to super duper performance TDi stuff).

Any opinions?

[LukeM]

no idea but sounds interesting, pop by swindon

[Chrispy]

On someone elses car this exact same thing was caused by a faulty vacuum box (the one on the O/S suspension turret).

It has also been suggested that vacuum leaks to this box etc will cause excessive/ erratic boosting.

[ultra_joel88]

Is that held boost, or spikes?

[Tech1e]

Standard boost is about 1.5 bar anyhow.

[ultra_joel88]

Mine occassionally spiked at 21psi (1.5BAR) in standard map guise, FYI.

Held at 18-19psi (1.2 - 1.3BAR)

[Lofty86]

no idea but sounds interesting, pop by swindon

Where abouts are you?

Its not erratic boosting.

It spikes at 1.55bar(ish), then drops to 1.35/1.4bar for a split second, then holds 1.5bar.

It all happens smoothly, and doesnt keep boosting and loosing boost. Its not a bad drive, and as I said in my first post, it might not be a bad thing.

Just dont want it to be the end of the turbo or anything.

Also, point to make. Im using one of those dragon boxes, so it should be fueling for overboosting anyhow.

Got the box a while after the turbo was overboosting, so its not the cause.