Lost Boost, No Power!

[Trav33]

Hi All,

Swapped my turbo on the weekend.

Took it out driving tonight, all was sweet, but then up a hill under power it started missing, so i pulled over and it was running rough, but got smoother after a minute.

Took off again, but now ive got no boost. The stock gauge is going from -7 to -3 under power.

Any ideas what would cause this? Have had a good look under bonnet, nothing looks out of place or missing or noisy...

New turbo = high flowed turbo

R33 Skyline, Mods = the normal Front mount intercooler, exhaust, pod filter

Appreciate any ideas!

[paulr33]

cooler pipe has come off or youve likely blown an intercooler hose clamp.

put soapy water on the intercooler pipework and look for buggles or check for obvious leaks. if not leeks then exhaust wheel may have failed. do you get an sqeauls or wines when it tries to come on boost ?

[Trav33]

Hey Paul, ta for your reply.

No noises at all when it tries to boost...

I guess it could be a loose intercooler pipe - i had a good look, and felt with my fingers, but you're right that soapy water would be better to detect leaks.

Any other possible causes?

[Craved]

enough of a leak to have no boost would mean that all the air is pumping out of the pipe... unless your running a MAP sensor it wont be that

check the wastegate arm on the turbo from actuator to the wastegate flap.

[Trav33]

Actuator arm looks firmly attached to the gate on the turbo. Do you think i should rev the engine and see if the gate is opening at lower pressure than it should be?

[Craved]

shouldn't open at all when stationary

aslong as it looks firmly attached

kick the exhaust at the cat when the car is off to listen for loose material in the cat .. ie exhaust wheel

[RANDY]

Got an aftermarket dump pipe? I had one that smacked up onto the exhaust wheel of the turbo, and didn't let it spin. Possibly the new turbo has a bigger (and metal) wheel, and you have the same thing that I do?

I had no boost and terrible performance, but I did notice a soft whistle sound... prolly the exhaust rushing past the locked up exhaust wheel.

I'd suggest you pull off the intake piping to the turbo, and see if you can manually spin the turbo compressor wheel. This is what my mate told me to do, and how I found out what my problem was.

[Trav33]

Randy,

Good idea... however the turbo did run and the vehicle did drive for a few hours... and the hi-flow turbo is "Bolt-On"... so i doubt it's that...

Hrmm... might have to pull off intake and spin shaft... any other ideas if this is ok? Still have to get some detergent out later today to look for intercooler leaks, but i doubt this is the problem.

[png godzilla]

this is a great method for checking for leaks IC side or Exhaust.

I use Plumbers Test plugs to block the intake (x2) & another one to block the exhaust, just drop it at the cat eliminator pipe (or Cat) & wind it up inside the end of the pipe until it seals.

mines an RB26DETT, with HKS front Pipe so i need 3 x 3" Test plugs.

then you leave all but one blocked & open one only & apply compressed air easilly & straight away you can see where the leaks are either on the pressure side of the IC, the Plenum side & the exhaust!

found out my Intake plenum was leaking on runner # 3 last week. always heard a little whistle from the front, but now i know what it is!!

great trick, worth trying!

[RANDY]

If the turbo ran for a while... maybe it wasn't getting oil or something from a blocked pipe? And now it's seized?

Either way, intake stuff off, spin wheel, should tell you if the turbo is even working. For it to have no boost, you'd have to have an entire intercooler pipe completely off or something. The plumbers test sounds like a good diagnostics thing... but i'd personally do that after checking the easy stuff first.

[WazR32GTSt]

this happened to me when i had my rb25 turbo installed onto rb20

my problem was that the actuator arm had come loose from the wastegate

[BezerkR32]

Not unusual for oil feed line to block as it has the restrictor in one end. good chance you might have siezed it. it would be a obvious leak for you to have no boost pressure and car would not idle either.

If the turbo ran for a while... maybe it wasn't getting oil or something from a blocked pipe? And now it's seized?

Either way, intake stuff off, spin wheel, should tell you if the turbo is even working. For it to have no boost, you'd have to have an entire intercooler pipe completely off or something. The plumbers test sounds like a good diagnostics thing... but i'd personally do that after checking the easy stuff first.

[Trav33]

Bad news, took intake piping off and shaft is stuck! No movement.

What would cause a new turbo to sieze? I had the oil line drilled out and upgraded to enable more oil flow. Not happy.

[RANDY]

damn man... that's not good news.

For the reasoning, see bezerk's post... and mine above...

Possibly it had no oil, so it just overheated and locked up.

Still, rule everything else out first. Does your dump pipe have that little pipe that bangs up against the exhaust port on the turbo? If so, drop the dump off and try spinning the turbo. If it still doesn't spin, then you can be pretty sure that nothing else is holding the shaft in place.

Maybe talk to the place that did the highflow and get them to check the turbo out... maybe they botched something, or maybe they can prove conclusively that it was due to your installation.

Good luck!