Jump to content
SAU Community

Recommended Posts

Hey guys.

Some of you may know I been stressing over if I have a vac leak or not and after hooking up a compressor I couldnt find anything.

Finally decided to give the car a beating today after getting my clutch sorted and I had a strange issue.

Seems in 2nd where it used to build up 20psi very quickly is only building up to around 18 and is pretty sluggy.

Once I get it into 3rd it makes 20 psi still.

Just seems odd as it's running straight off the actuator which is a 20psi spring

Any ideas would be appreciated

Link to comment
https://www.sau.com.au/forums/topic/408445-boost-difference/
Share on other sites

Already Smashed out ages ago

I have tried the pressure test and tried blocking off all the parts air was coming to but couldn't find anything.

Also checked all the cooler piping.

I wish some in the ACT had a smoke tester because that would be perfect

Already Smashed out ages ago

I have tried the pressure test and tried blocking off all the parts air was coming to but couldn't find anything.

Also checked all the cooler piping.

I wish some in the ACT had a smoke tester because that would be perfect

Autotech do I believe.

Think about what boost is, and what determines boost. This leaves you with a handful of possibilities:

Leak in intake

Faulty BOV

Faulty actuator

Faulty boost controller

Blocked exhaust

Then on the unlikely possibility it's the turbo at fault:

Faulty waste gate flapper

Could also be faulty boost gauge showing wrong when nothing has changed.

Nah you can hear it whistle when around about -40 to -50 vac

also still has a whine noise when on boost.

You can also notice it is lacking in power.

Jez has told me to make sure the turbo is secure which I will check as soon as I get home.

Also will check all the bolts on the exhaust.

When you stick your head in the engine bay and rev it real hard you can smell exhaust fumes but unable to determine if thats just blowing back from the exhaust or not.

But yeah checking all the bolts and will report back

Yeah the turbo dump was a little loose.

We did them and checked the turbo bolts but they seemed fine.

Took it for a spin and it was boosting fairly well.

2nd gear seems to make boost different to when in 3rd which I didn't think was possible.

On the way to work it still managed to whistle again at around the same vacume.

Not sure if related but I cleaned the AAC and put that back on plugged it all back in and no matter what I do the car idles at 1500rpm unless I unplug it

Maybe the AAC hose is damaged? there was a thread like 3~4 years back where one guys' AAC hose (from the cross over pipe) melted and couldn't work out why it was running like shit. Turns out the underside melted because of his turbo.

Just a though :)

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Hows your intake piping? Are you still running stock? Having in the stock AFM position would mean, if the BOV was shut/venting out, it'd create the almost stalling kind of effect right // "the rich pulse behaviour" due to MAF thinking air is flowing ? But this would be better than having the bov in the stock position + MAF on/just before cross over piping right?
    • Essentially, yes. Although I wouldn't put the AFM on the crossover pipe. I'd want to put it into what amounts to the correct size tube, which is more easily done in the intercooler pipework. I bought a mount tube for card stile AFM that replaces the stock AFM - although being a cheap AliExpress knockoff, it had not flange and I had to make and weld my own. But it is the same length and diameter as the stock RB AFM, goes on my airbox, etc etc. I don't have a sick enough rig to warrant anything different, and the swap will take 5 minutes (when I finally get around to it and the injectors & the dyno tune).
    • So to summarise, the best thing to do is to move recirc to between turbo and IC, and maf on the crossover pipe. Meaning I'd need a recirc flange, drill a hole in the piping on turbo outlet area. And drill hole on crossover to fit/weld maf sensor? Either that or put the MAF on the turbo inlet right?  Is an aftermarket recirc/blowoff valve recommended? Do currently have family in Japan so could probably bring something back with maybe a cheeky lil SuperAutobacs run?
    • Yep, so far most have said that it looks like corrosion on the wall from piston not moving. Which then has probably damaged the oil rings and caused those vertical marks. The longest the engine was still after the rebuild, was the winter of 2018 - 2019, plus the boat trip to Japan. When I shipped the car, it had normal gas in the tank but before that winter pause, it had E85 in tank.  In any case, even if either one of those was the cause, it happened close to 6 years ago and the car has been driven something like 30 000kms after the fact. Again, apart from the plugs and the dip stick, there is nothing in the way the car runs that would indicate what has been going on in the engine. I am going to consult a shop and ask their opinion, what would be the best approach. I do have some access to a garage I could use to diagnose further myself, but time is very restrictive. Might end up buying another engine that could be used while this one is being remedied. Without pulling the head, it will be impossible to find out if it needs another bore, but here's to hoping a hone would suffice.  Goddamnit, I would really have preferred this not happening.  
    • Boot is going to be replaced eventually. I just wire brushed what I could and rust converted. Then painted in rust kill primer. the spoiler also got repainted and plugs replaced on the ends. The under side of the bonnet is going to be black also, currently white. But red on the top side, same colour code as the silo to begin.
×
×
  • Create New...