Installed New Turbo And Can't Get Boost?

[JET-25L]

Ahh yeah as title says... as silly as it seems... I blew my old turbo and bought a highflowed one second hand. It was near new and had no shaft play. I had it quickly checked by MTQ up here and he said it looked good.

Now yesterday i put it all on exactly the same as i pulled it off... got the car running fine... except when i pull the throttle cable or go for a little drive there's NO boost and when there's meant to be boost it blows slight smoke (from running too rich from no boost i presume). The new highflow came with a hks actuator which is what i originally thought MIGHT be the problem... so i put the standard one on from the old turbo and no difference...

The wastegate valve stays shut the whole time and the shaft doesn't move at all under throttle and no spool/doesn't go above 0 on the boost gauge.

Both the exhaust and compressor wheels spin freely and at the same time (one spins the other obviously). I did have an exhaust leak between the manifold and the turbo but put a new gasket in there this morning and now it's gone.. but same problem... not going above 0 only staying in vacuum. I've checked all the intercooler pipes/vacuum lines etc etc and am now stuck. I would think it would be something fairly obvious!

So if anyone has any suggestions of what it could be please help me out... I really don't want to think it's the turbo afterall but if anyone can help me before i start pulling it all off again i'd much appreciate it!

Thankyou in advance...

Steve.

[paulr33]

wastegate flap stuck open

intercooler pipework loose or leaking

vac lines loose or leaking

basically its leaking pressure or the wastegate is always open

thus the turbocharger nevers gets to spin fast enough and doesnt build any positive pressure

[JET-25L]

wastegate stays closed.. actuator doesn't move.. could a small vacuum leak eg in the rubber snorkel or something make it produce NO boost? It sorta sounds like there's an air-ie noise coming from that side and no not from the air filter lol. I'll keep looking but yeah.

So a vacuum leak could stop it producing boost/spooling and therefore stop the wastegate from opening???

[~R33AzzA~]

What does it sound like, normal? Have you checked the bov, long shot but could be leaking?

Gl with sorting it out.

[NWR31]

compressor wheel nut not torqued up enough?

[JET-25L]

Okay i took the rubber snorkel off from the turbo and thus removing afm as well... and started the car and it idled fine and when i rev it a bit i can see the compressor wheel spinning.. so it's definitely capable of producing boost... it's just not??:s

[JET-25L]

bov should be alright... haven't touched that at all and yeah once again it's getting no spool or positive pressure whatsoever..

Damn cars. I'm sure it'll be something really obvious that i'll kick myself for but i've checked everything 1000 times and pulled off/put on as well. hmmmmmmmmm

[Angus Smart]

you get all the vaccume lines back on the way they came off?

[dano4127]

is this free reving on the spot or when driving? How far are you reving it too?

[JET-25L]

Hey both. I was free revving it at first then i thought no i'll take it for a drive... went about 100m up the street and back and i accelerated just hard enough to where the turbo should be spooling.. maybe went to 3000rpm but there was nothing. Was just running really rich.

It's highflowed it shouldn't be that different coming on boost pretty much same as before. The blowoff valve doesn't make a single noise either..

[JET-25L]

Alright i took it for a bit of a harder drive just then and i can get the bov to open very very slightly but boost still isn't above 0 and yeah.

When idling how fast is the turbo supposed to be spinning??

[blind_elk]

I doubt 3000 rpm is going to produce any boost. It is highly unlikely to produce any on a "free rev" (even @ 6000) . You need to load up the engine to get boost.

Also, check ALL the intercooler piping between the compressor and the throttle and confirm all the joints are intact.

[JET-25L]

Well before i could just give the throttle cable a tug and the turbo would spool and then the bov would sound... now it's doing neither... and no matter what i do/how i drive i can't get the turbo to spool or produce boost. If i go for a hardish drive down the street the boost gauge doesn't even get close to the 0 on the gauge... However both wheels are spinning, wastegate flap opens and closes when disconnected from the arm.. the actuator spring is working fine when i pull it... and hmmmm

Thanks for everyone help. I'm starting to consider the possibility that it's the turbo... Anyone else think that's a possibility?? Is the compressor wheel supposed to be slowly spinning when it's just on idle? I can concentrate on one blade the whole time it's spinning that slowly.. but if i pull the throttle it spins rapidly like you'd expect it should..

[NWR31]

i still think its possible (unlikely i know) that it could be the compressor nut tension.

it could be loose enough that at idle & free rev it doesnt spin on the shaft but when the turbine really gets moving the comp wheel could spin/slow down & not create boost.

im not saying thats yur problem but it is possible i believe.

good luck

[JET-25L]

Well if it's that i should let it idle like before without the afm and see if the shaft is spinning faster than the compressor wheel.. I'll give that a go or see if i can tighten the nut at all.

[blind_elk]

Your boost gauge is connected / working? If it's spinning wheels, then I would hazard a guess that you have some additional power from boost happening.

Maybe it's such a large turbo that it doesn't produce boost until quite high revs and loads.

[NWR31]

if it's spinning wheels, then I would hazard a guess that you have some additional power from boost happening.

he doesnt mean road wheels

[NWR31]

Well if it's that i should let it idle like before without the afm and see if the shaft is spinning faster than the compressor wheel.. I'll give that a go or see if i can tighten the nut at all.

no, what i mean is it might not start spinning on the shaft until the turbine/shaft is under load.

to be able to tighten the nut you will need to remove the dump, like i said this is just a suggestion to what might be wrong, hopefully its something easier.

[JET-25L]

Well i just checked all the intercooler pipes again... let it run and got a mate to yank the throttle cable and felt them all to see if I could feel any air escaping but they all seem fine and i can't get any movement out of them at all if i shake them around... all the vac lines are perfect and i can blow through all of them so there's no blockage... and they're on exactly the same as before..

Another funny thing... not sure if this is normal or not... but when i started the car the compressor wheel was spinning really slowly... then if i give it a squirt it starts spinning quickly and keeps spinning quickly even when it drops back to idle revs.... is that normal?? Is the turbo supposed to change rpm like that...

[Granthem]

I guess thats the turbo gaining RPM and then not returning to its normal spool speed as the momentum is still rotating it (hence why people use turbo timers, to give the turbo time to reduce its RPM)

Very strange indeed. No blocked cat or something like that choking up the whole car?

Edited September 3, 2008 by Granthem