1986 300zx z31 Turbo - Maintenance Questions

[SAIAF1859]

Hi, new to the Z's. I'm pretty good with a wrench, not so with major mechanical.

Just picked up a z31 in mint condition from a guy who previously owned it for 20+ years.

Needs a little maintenance work. Gonna start on the valve cover gaskets today.

Also, seems like the turbo is not working. What the best way to actually diagnose if the turbo is not working? I've never had a boosted car so I have no idea. The previous owner told me the turbo doesn't work and his mechanic told him it would be best to leave it in a non working state as it might put too much stress on the old engine (180k).

I jacked the car up to try to take a look at the turbines in hopes I could feel if it is not in a working state. Unfortunately, the the exhaust tube running from the cat to the turbo has bolts that are rusted shut. I'll probably have to take it to an exhaust place to have them heat it up to force the bolts off. This will take some time as Im on a budget, so shooting for next month to do this.

Any other way to know if the turbo is actually not working?? Any help with the exhaust bolts would help too.

Im thinking its the turbo seals if anything that the issue, but the turbines on the exhaust side might be all warped depending on if there are leaks there and how bad they are, so might have to get a new turbo which will take some time to save the dough, hoping for the rebuild route as long as the turbines are good. Doesnt seem like the turbo is smoking due to bad seals also. I did notice smomking but I think that is from the valve cover gaskets being bad.

If the turbo is bad, is it ok to drive the car with the turbo not working?

Thanks.

[evildky]

A boost gauge is the easiest way to see if the turbo works, drive the car, press the pedal to the floor, if the boost gauge never goes positive you either have a massive boost leak or a bad turbo.The next thing to do is to remove the air inlet piping from the turbo inlet, stick your fingers in there and feel for excessive movement or if the rotating assembly is seized. A turbo can boost and exhibit normal free play and still be bad, when the seals go bad on the exhaust side (turbine) you get black smoke out the exhaust, when the seals are bad on the inlet the up pipe should have an oil trail in it, just pop it off the TB and look for a trail of oil inside, no trail no problem with the compressor oil seal. His mechanic clearly doesn't know VG30ET engines If he thought the 180k mile engine couldn't handle a fresh turbo, it'll be fine, it could likely take some upgrades and still be dependable for a long time. Unfortunately the turbine housing is proprietary so you're stuck finding a used replacement, having yours rebuilt or have a new center section installed in your housing.