Gtr Making No Boost!

[Fry_33]

It may help to see a pic or two, especially of the pipe you replaced, as this may give some ideas.

[whiteboy01]

It may help to see a pic or two, especially of the pipe you replaced, as this may give some ideas.

Will do tomorrow. So it's a leak some were. Spose it's a good thing that it's not the turbos!

[swanny180]

Yeah definitely sounds like a leak.

Be careful driving it like it is onto boost - basically it will be like not having a working wastegate.

Your turbos will start spooling, but the pipes wont hold positive pressure. So you can have the turbos spinning really really fast, fast enough that theyd be making like 20psi normally, but with 0psi actual manifold pressure, so thats all your wastegate sees and it wont open to regulate the turbo's speed.

So yeah, dont go hitting 0psi because as soon as you do that you dont know how hard your turbo is being worked...

[whiteboy01]

Yeah definitely sounds like a leak.

Be careful driving it like it is onto boost - basically it will be like not having a working wastegate.

Your turbos will start spooling, but the pipes wont hold positive pressure. So you can have the turbos spinning really really fast, fast enough that theyd be making like 20psi normally, but with 0psi actual manifold pressure, so thats all your wastegate sees and it wont open to regulate the turbo's speed.

So yeah, dont go hitting 0psi because as soon as you do that you dont know how hard your turbo is being worked...

Shit. I have been driving quite sedatly but i have just wound out a gear to go fast. Hmm. I think I have done that about twice.

[Bumblebee]

i told u it wasnt the cat. ive heard the BOVs have a hole on the bottoms of them.. ur meant to put a screw or something inside?? .. theres 2 of them so obviously 2 screws to block the holes..

where abouts r u located? if ur in melb i could come up n have a peek

[SLIPPERY]

Yeah definitely sounds like a leak.

Be careful driving it like it is onto boost - basically it will be like not having a working wastegate.

Your turbos will start spooling, but the pipes wont hold positive pressure. So you can have the turbos spinning really really fast, fast enough that theyd be making like 20psi normally, but with 0psi actual manifold pressure, so thats all your wastegate sees and it wont open to regulate the turbo's speed.

So yeah, dont go hitting 0psi because as soon as you do that you dont know how hard your turbo is being worked...

The wastegates get their pressure signal from the nipple on the turbo outlet, so having a leaking cooler pipe further down the line isnt going to pose a problem

[T04GTR]

ok guys. wonder why its not making boost?

heres what happenss whenj one turbo lets go. the one turbo that is working instead of making pressure in the manifold it blows straight out the front of the blown turbo. cos its not turning. would be pretty easy for the ecu to get confused with air blowing out one afm and in another...

then again.. i dunno. it just looks like a blown turbo. a leak that bad would make it stall. check the intercooler piping on the passenger side onto the coller. they tare often if the engine mounts are weak.

[whiteboy01]

I will show you a pic of the pipe i replace because i can't get to my till this arvo

How do i check if one of the turbos is gone? Without taking the dump pipes off or engine out.

I live in Western Australia, Geraldton population of about 10 000. No one he knows about skylines/GTR. When i took it to a mechanic i overherd one of the blokes say "they like a SS just put the same shit in". He was talking about the oil.....

I have taken both pipes off and i can feel it sucking real good. The boost gaugealways goes out of negative psi and holds at 0 psi.

Edited September 25, 2007 by whiteboy01

[Ant97GTR]

Check all your small vacuum hoses controlling boost and connecting to your ecu....I had this exact problem and it turned out to be a split in one of these hoses.

[Hella Flush]

it will be a vac line/your boost gauge

[whiteboy01]

it will be a vac line/your boost gauge

I'm trying to get my head around this whole situation.

Turbos are fine?

Pipes are fine from the turbos?

It's whats controling the boost. I have no boost controler. So it's a VAC leak somewere. Do they normaly make a sucking noise? Any BIG clues i should look for?

[SLIPPERY]

theres plenty of pressurised hoses around the plenum but it needs to be a sizable leak to make no boost, but not big enough for the car to stall

have you looked there?

[whiteboy01]

theres plenty of pressurised hoses around the plenum but it needs to be a sizable leak to make no boost, but not big enough for the car to stall

have you looked there?

Ok update time.

The car has been in bits looking for this leak(s). Deciced to put the cat back on and saw that it was really blocked up and black. I held it up to the sun and all i could see was a hole the size of a HJ's Straw! So i brought a new one

Heaps of NA power but still no boost. Revs alot harder and pulls a little bit better but still no boost.

I was waiting in the drive though of Red rooster and it was having trouble IDLING and nearly stalling. Boost gauge was going all over the place. Keep smelling fuel all the time and blowing HEAPS of black smoke.

Driving home the car acted normal as well. Still no boost. I can here a hissing sound ner the dump pipes, but not in the engine bay.

Question Time:

If one of the turbos breaks a exhaust wheel off can the other still make boost? Like instead of make 0.8 bar it will make 0.4 becuase one making the boost not booth?

I don't have the money for replacement turbos so if i continue to drive the car will the engine suffer? Do i risk anything. I drive 300km a week, and get paid monthly so it's going to be hard.

Is there a garret drop in replacement that is as reponsive as the stock ones.

Instead of buying the garrets/HKS would it be wise to rebuild the current ones with steel wheels. I'm chassing a reliable 300kw ATW

Thanks again for the help you guys have been awesome!

[robots]

Hmmm. Stupid question. Check your boost gauge hose. Once it read lower on my car. Reason: hose was nearly off.

[shepo]

one other possability could well be your intercooler, it might sound strange but something like a stone may have flicked up and punched a hole in it. this would explain a lack of pressure in the system. it might sound crazy but its worth a look.

[whiteboy01]

OK guys

I have biten the bullet and brought some secound hand turbos to replace the ones in there.

I will be ripping every thing out and QUAD checking everything!

I pick up second hand 32 GTR turbos for 450 bucks. Is that a good price?

[WRRR]

Before you go ripping verything out do yourself a favour and grab a can of aerostart or similar (as was suggested previously).

Have the car idling and starting at one end (suggest the intake given your descriptions) and squirt the aerostart along the intake runners - one at a time, then underneath the plennum, back along the intake system, etc at each joint, hose or such.

If you have a vac leak the engine revs will increase when it sucks in the aerostart. That vac leak will either throw all the EMS out or bleed off your boost or both.

If you find the b..tard - bingo. If not your plan B is ok but don't underestimate the pain - and get theos turbs checked before you put them in.

Cheers

[EVIL TWIN]

OK, now this is a little exteme, but it doesn't look like you have much option and it just may work. Failing having a proper mechanic look at it, if it is indeed a leak, check for it by taking all the piping off from the turbos to the inlet manifold, including the intercooler. Put them all back together on the ground. Now you can check a couple of ways.

If you have a pool, get a leaf blower or similar, seal it on one end, seal up the other end, and drop it in the water. Turn on the blower and look for air bubbles. Just like finding a puncture in your bike tube.

Bush f**kanics at it's best!

If no pool, seal a water hose to one end and seal the other end up. Turn on hose and look for water leaking out. You might be able to do this one with everything still on the car by taking off the connection of the pipe you replaced and the connection to the inlet manifold, but it might be a little hard to see where the water is coming from.

Don't forget to dry it out completely before re-installing!

If it's not a leak, but is one of your turbos, then the replacements will have to do, but get them checked first. Also might want to check if your wastegates are stuck open or BOVs are stuck open?

Edited September 26, 2007 by EVIL TWIN

[T04GTR]

look. seriously. to check you need to simply get someone to rev it up while you put both hands over the air filters. one will suck and one will blow if a turbo has let go.

do this before you do anything else!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! for f**k sake

[whiteboy01]

look. seriously. to check you need to simply get someone to rev it up while you put both hands over the air filters. one will suck and one will blow if a turbo has let go.

do this before you do anything else!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! for f**k sake

They were both sucking and blowing swaping even? Very strange.

I did do the Start you bastard trick with no success. That is what i meant by checking the pipes sorry.

The way i think of it is if the turbos are fine or f**ked i have a spare set to build up or sell.

Im going to try the f**kanics and put air though the system. The turbos are nearly out now, just got to remove the dump pipe so i can have a look. All in all i don't think it's a big deal doing the turbos, i get to learn a f**k load and have in the progess. Now to finish it for the Show and Shine on sunday