Turbo issue??

[TREX]

Hey guys i am having an issue but not sure what it is..
My thought is rear turbo.

Symptoms:
- blows smoke on and off
- rear turbo screams when on boost (the sound of a fly next to your ear but loud loud) the front is dead quiet.
- boost is coming on later than usual.
- ran a 15.2 1/4

mods:
-hks fmic
-3" exhaust
-3 port solenoid
-walboro 255
-coilovers
-k &n panel filter
-rebuilt auto

What i am wanting to know is how can i check my turbos? preferably without removing them.

Thanks in advance

[Davezj]

here is a few thing you can try with the turbos on the car, it does not look at the exhaust wheel for oil leaks and play but you can check the compressor side of the turbo.

Take the inlet pipe work off both turbo and check for excessive oil in the inlet compressor wheel, a little misting of oil is OK as it can be there from the rocker cover breather pipes. (checks for oil seal fail).

Visual check on compressor wheel for damage (checks for bearing failure).

check for side to side play on the compressor wheel buy putting you finger on the end of the shaft and wiggle from side to side. there should be none to very very slight wiggle If bearing are not pumped up with oil. 0.5mm movement is very very slight movement, ensure the compressor wheel still spins freely. (Checks for bearing failure).

check compressor wheel end float by pulling the compressor wheel in and out. there should be no movement (Checks for bearing fail).

the only thing you can do if you have no experience looking at play in the turbo shaft, then compare front turbo to back turbo to see if there is any difference.
you seem to think the front turbo is ok, but what you have to remember is if both turbos are original fit and 15+years old, if one has warn out te other will not be far behind.

[TREX]

Hey Davezj,

Thanks for the quick response. I understand that if one is flogged the other wont be far behind.
Do you know what a standard vr4 legnum would run 1/4mile?

[Nick Mann]

Standard 1/4 mile times are high 14s. You aren't that far off so you might just have a small boost leak. That could give air rushing noises, smoke and a small loss power.

Smokey turbos on the VR4 are usually worse under vacuum situations. Find a long downhill bit of road, and then engine brake all the way down without touching the throttle. After 15 seconds there will be a slight haze in the rear window which will become a good puff as you touch the accelerator.

[Davezj]

Good advice from nick

[Pugme]

Mine smokes like a trooper when I'm queuing to get out of a car show.

One or two blips of boost normally clears it out tho

Is this a bad sign on my turbos too?

[Confused]

No, that's probably just condensation.

[Pugme]

I love it when there's a Ltd edition corsa in white behind me as I exit haha

I can usually coat the bonnet bumper and one wing in black **** haha

[Confused]

The black **** is probably just the condensation or trace amounts of oil which naturally appear in the exhaust, or the loosening of some of the carbon that's built up on the inside of the exhaust, and nothing to worry about!

[billybobboot]

If its making a noise is it like a police siren e.g. a high piched woo sort of noise if so its the bearing starting to go. There getting lazy e.g. sticking why its prob spooling later rather than replace try taking it off and flushing all the old cruddy oil out and putting new oil in.