410 replies to this topic

[duncanm]

high and hunting idle sounds manifold leaky to me. Idle should be lower (~650) and rock steady.

 

Your extra ground - if it really changes things - is interesting.. Note that the camshaft sensor wiring is NOT grounded anywhere on the block. It uses an earth shield which I'm pretty sure is grounded to the chassis, so adding an earth wire near it should do nothing.

 

Does it turn over ok  or labour a bit ? Check your big-arsed ground strap which should be somewhere down around the starter - it should be plenty sufficient to ground the block.

[LukeFranky]

I feel like I still have a leak somewhere but have no idea where!

 

Last night the wife and I pulled the intake apart again. Tightened everything at the risk of stripping threads. Took the plastic hoses off the intercooler and put them back on tight. Everything has new gaskets.

 

Took it for a drive and could still hear the faint whistle under boost. Engine light eventually came back. My next step is to do a pressure test.

 

 

On a semi-related note, while test driving I came up behind this woman: https://www.dropbox.... place.mp4?dl=0

She was on meds (or maybe off them). When she pulled in at the servo I stopped her getting back into the car until coppers arrived.

[allpaw4]

Good job. That's pretty bad, nice work on stopping her getting back in the car.

[Robbks]

Did you check the plastic intercooler pipes for cracks?
they have a habit of splitting between the wrinkles

they are also a great part to upgrade to silicone items, they are very restrictive to airflow our of the turbo's

[duncanm]

Robb - think he's already gone silicon.

 

For pesky minor intake leaks - spraying WD40 or carb cleaner around whilst idling is probably the easiest way to find them.

 

As you suggested earlier - a pressure test may be the best way to go.

[LukeFranky]

Robb - think he's already gone silicon.

 

For pesky minor intake leaks - spraying WD40 or carb cleaner around whilst idling is probably the easiest way to find them.

 

As you suggested earlier - a pressure test may be the best way to go.

 

I went silicone on the intake tract and intecooler to throttle body but not the turbo to intercooler hoses yet. My plastic hoses looked to be in reasonable condition. The secondary turbo hose was only replaced less than a year ago.

 

I've tried copious amounts of carby cleaner. No luck. I must be missing something obvious.

[Robbks]

I'd move into the BBoD and make sure that everything is spot on in there.
also make sure your vacuum tank and the big hose that supplies it is in good order

all of that system is part of the intake too with boost and vacuum sources.

[LukeFranky]

Assuming if the vacuum tank had a leak, then removing the vacuum line going to the boost actuator for the secondary turbo (the one attached to the intercooler pipe) wouldn't have any suction on it with the car off?

 

Every time I've pulled that line off it has had suction on it. Does that rule out vacuum tank?

[Robbks]

Yeah I'd say so.
Stuck solenoids or leaks on the positive pressure sources is where you need to be looking I guess.

Mine was greatly simplified by bypassing the ECV Positive Pressure Solenoid and Duty Solenoid
Aswell as using stand-alone boost control.
it removed about 5 metres of hose and 3 separate solenoids plus all but one of the restrictor pills I believe.

It's a "standard" mod that I've done for a number of owners here in Tassie to help troubleshoot things (based on Billsy's advice)

 

[LukeFranky]

Interesting. Would that mod need a retune?

[LukeFranky]

Oh, I remember reading about that mod now. Yeah, it won't suit the MY03.

 

Also ordered the CTS today. I'm going to buy more silicone vacuum hoses to replace all my old lines just in case. Though the ones I haven't replaced yet were in OK condition last I checked.

[Robbks]

The mod makes them run like shit if you are trying to use the factory boost control, 
the factory control itself is another typically bad design.

using a good stand alone, closed loop boost controller, especially one with independent RPM boost settings makes boost delivery even better. as it minimises VoD by closing the wastegate during the transition.
there's at least 4 Late model Gen3's (B4's and GTB's) that ran better than new after I modded them, and adjusted the ECV pre-load properly.

Most people also use the compressor outlet nipple pressure source and connect that to the boost controller, (either manual, electronic or directly to the WG actuator)
the problem is the pressure build up between the primary compressor outlet and the TMIC is HUGE (put a boost gauge on it and see for yourself.)
this has the effect of blowing open the gate far too soon, and keeping it open during VoD.
if you move the pressure feed for your boost controller to a direct manifold source, you get much better boost control.

Using the pressure ports on the Secondary TMIC Elbow is another mistake a lot of people make, it fills up with oil and blow-by which then fills the solenoids and lines,
particularly the ones the feed the Positive Pressure port and ECV duty solenoid.
the bypass simply reduces all of this mess from ever occurring again.

These mods are the definition of Keeping it simple.
remove problematic components in a needlessly complex system, and use the system's normal mechanical operation to achieve the result you want.

[LukeFranky]

So I tried a pressure test. I couldn't get it to hold any pressure whatsoever, but I couldn't hear where it was escaping. Must be a big leak.

Might try making a DIY smoke machine...

[allpaw4]

I've seen online someone make one with a cigarette, 1.25l bottle and an air line.

[LukeFranky]

So I put together a state of the art vacuum leak tester using:
- Milo tin.
- Vacuum hose and a plastic joiner.
- Tire valve off an old wheel.
- Small compressor
- Peekay's oily rags (not even joking)
- A lighter.

Here's the result:
https://www.dropbox....070715.mp4?dl=0

I think it's the intake gasket again. There was a lot of old crap on the surface and I cleaned off most of it but maybe I didn't do a good enough job.

Are there any vacuum lines running beneath the intake manifold on the passenger side near the BOV? I want to check those first.

[duncanm]

that's actually really good news -- it may be the source of all your problems.

[LukeFranky]

Allpaw4 I thought about using a cigarette but I might kill my wife in the process. She's anaphylatic to cigarette smoke...