Well tommorow me and my pops are going to check out a 90' 300ZX TT. It has 156K miles. Everything is original except for the exhuast. I'm not really sure if the turbos were rebuilt or replaced. How would i know if the turbos are seized? Is there a noticeable loss in power? Overall the car is in great condition. The turbos concern me because i read somewhere here that they usually seize up at like 120k.

 

you can tell in spool up time i believe if tehy lag alot. then tehy have hella lotta seize. if they spool up nice and fast then no problem.

 

at what rpm is normal spool time? i drove the car and it spooled at around 4k. well it doesnt matter because the exterior and interior is in excellent condition. once the engine goes down im going to have the engine replaced. the mods on the car are borla exhaust, kn intake, new clutch, greddy turbo timer (i think), f+r strut bars(don't know what kind but it's red at both ends where they bolt up), drilled rotors up front, 17" wheels and that's about it.

 

ok turbos are goign caca. i believe they are suposed to spool arround 2500 ish. and upgraded (bigger turbos) skyline R34 turbos to be exact spool up at no more than 3K. turbos = caca

 

i've seen on one post that spraying wd-40 in the turbos would help them spin more freely. would it be worth a try? is it safe?

 

I did a post where turbos get hard to turn after they've sat for a while. I heard where people spray in wd-40 and then spin the turbo with a drill motor to loosen it up. I did this on a turbo that I have and it loosened up alot. I don't know if your intent is to do this with them on the car and you're just trying to get them to run better or what. But.... if they're on the car, and the engine has been running, this wouldn't be of any benefit because the turbos should be getting oil from the engine.

I believe, a good sign that the turbos are going bad will be exhaust smoke. As they wear, the shafts will eventually get loose in the bearings which will wear out the oil seals causing the oil leak. I wouldn't run worn turbos too long because they are rebuildable, that is until they get so worn that the turbines inside start to hit the housings, which destroys them.

 

i'm glad i didn't see any exhaust smoke on idle. can't remember if i saw any while driving. oh well if we get i'l make sure i check it out. and for the turbos im thinking about getting the new stock turbos on z1motorsports.