Only reaching 1/2 boost... :-(

[Ash10]

My 'R is only boosting half as much as normal - about +3.5 on the gauge.

There's a distinct lack of power (although it's still perfectly driveable), and it seems to be a little noisier than I remember it. Sounds like a split/loose/disconected hose - I've had a quick look and can't see anything obvious.

Any suggestions where to start looking?

 

[herbie]

I would start with a fault code check. See sticky at top of this section.

 

[Ash10]

I would start with a fault code check. See sticky at top of this section.

Been there, done that - 55, AOK :?

 

[Fast Guy]

Is the car running ok with this boost? No coughing/ spluttering/ misfiring etc?
Has it just gone like this or has it always been like it? No restrictor in the restrictor hose?
If it's noiser than normal, check your manifold, and turbo to manifold bolts haven't worked loose.
The gauge may be faulty, you could have a boost leak,faulty wastegate or wastegate actuator, faulty turbo to name a few. :?

 

[Ash10]

As an update to this, the (Nissan) garage diagnosed and replaced the turbo/manifold gaskets (mounting bolts has worked loose). Boost improved slightly (to about 3/5 full) and the excess noise disappeared

However, apparently the turbo has quite a bit of end-float and the impeller tips have worn down a little on the inside of the casing

Before I splash out on a recon turbo, are there any quick tests that I can do to double-check that it's not a sticky actuator? Maybe disconnect it (pipes, wires, etc)???

 

[Fast Guy]

If the blades are wearing on the housing, then there's enough play in the turbo for it to move and allow this contact. This means your bearing is going and it's only a matter of time, so I'd suggest you look at replacing it before it fails and possibly causes any internal damage to the engine.

 

[geetee]

what he said :lol:

bits of turbine blades falling off you can live with - you might get fireworks from the exhaust when they finally collapse

bits of impeller... hmm... let's see....

seriously, if there's enough movement in the bearing to cause the blades to be wearing against the housing you have to bite the bullet and get a new tubby or get yours rebuilt - if the housing isn't too worn.

A new tubby even if you buy it in the UK is going to cost a lot less than the alternative.... at which point you'll be getting the new tubby anyway.

Cheers
GeeTee 8)

 

[Ash10]

Fair comment guys - I suspected as much :?

I've only got the garage's word on the state of the turbo internals - whilst I have no reason to doubt them, I would like to double-check that it's not the actuator before I splash out on a new turbo...

So, is there anything that I can quickly disconnect to nobble the actuator?

 

[Brett G]

Pull the pipe off.... You should get max boost!!! :shock: Joke, don't do that

 

[Ash10]

Pull the pipe off.... You should get max boost!!! :shock: Joke, don't do that

That's kind of what I had in mind - if the turbo isn't making the boost in the first place (as suspected), then what's the harm?!

Would this be extremely ill-advised? Wasn't planning on ragging it like that...

 

[LeeSmith]

i wouldn't mate!! if your turbos is on it's way out and you push it twice as hard as it has been going, then it is sure to die!! & take your engine with it!!