zeeboost Posted March 19, 2013 Share Posted March 19, 2013 (edited) Just under a month ago I had a factory T3 off an '83 280zxt rebuilt by a reputable turbo shop that's been in business for many years. I just now got the engine fired up today, and with no exhaust bolted on the turbo, I noticed that it doesn't spin at idle. It will spin at 1500 rpms or so, but when you let off the throttle it doesn't coast to a stop...it's bit more sudden, as if it's dragging on something. I removed the oil drain and cranked the engine over, sure enough oil came pouring out, so lubrication shouldn't be the issue. I can spin the turbo pretty freely by hand, and from what I can tell, the blades aren't hitting the housing. I had to clock the compressor housing differently so that it would work with the n/a manifold, but all the bolts are tight and I can't see that causing an issue. Do journal bearing turbos have a break-in time? The engine's only ran for 20 seconds roughly, because the turbo not spinning kinda freaked me out. I'll probably call them tomorrow, but was hoping to educate myself on this a little more before jumping the gun on them. Edited March 19, 2013 by zeeboost Quote Link to comment Share on other sites More sharing options...
BLOZ UP Posted March 19, 2013 Share Posted March 19, 2013 Is the compressor outlet hooked up to the engine inlet? My last turbo on a VG30 wouldn't always spin at idle, and I could stop it with my hand if it did. Anything above idle though, and it would spin up. Also seemed a bit friction-y as far as spinning freely. My new ball-bearing one keeps spinning for a bit after my engine's turned off. And I've tried, only with only a little pressure on compressor wheel's nut, to stop it. Wasn't happening. But then I have way different manifolds this time around. Quote Link to comment Share on other sites More sharing options...
Tony D Posted March 19, 2013 Share Posted March 19, 2013 Ball Bearing Turbos have very little friction compared to journal bearings... The GT35R pins freely at idle, but neither my L20ET nor the L28ET stockers spun nearly as easily as that big honker! Quote Link to comment Share on other sites More sharing options...
zeeboost Posted March 19, 2013 Author Share Posted March 19, 2013 The only thing I have to compare is two other turbo Zs I've owned that had open downpipe at some point, I could hear them whistle at idle. They were was also a journal bearing. I may try to post a video up...it just doesn't look right to me. Quote Link to comment Share on other sites More sharing options...
zeeboost Posted March 19, 2013 Author Share Posted March 19, 2013 And yes the compressor outlet is hooked up. Quote Link to comment Share on other sites More sharing options...
R3VO 3VOM Posted March 19, 2013 Share Posted March 19, 2013 Thats odd. Can you spin it normally? Like I know its journal bearing but you should still be able to spin it when the engine is off. Just wont spin as long as a ball bearing unit. Quote Link to comment Share on other sites More sharing options...
dexter72 Posted March 19, 2013 Share Posted March 19, 2013 You might not have a problem at all, You may have to drive the car and get the turbo to spool up pretty good first. I upgraded to a t3-t4 turbo and had it rebuilt before installing it. It wouldn't spin at idle either when first put it on, so i took the car out for a quick spin. Drove it about a mile and checked to see if it would spin at idle, it did. Has spun at idle since then. Quote Link to comment Share on other sites More sharing options...
Snailed Posted March 19, 2013 Share Posted March 19, 2013 I don't quite get why it's assumed that a turbo should spin at idle, but it's a question that you can find the answer to on pretty much any car forum. https://www.google.com/search?q=turbo+won%27t+spin+at+idle&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a It's funny how many threads are presented with such distress too. Lots of exclamation points. Quote Link to comment Share on other sites More sharing options...
zeeboost Posted March 19, 2013 Author Share Posted March 19, 2013 (edited) I did actually search around, mostly found results on honda and dsm forums. There was a lot of conflicting answers and nothing concrete, so I came here. I hold this forum in pretty high standards as it's one of the most technical ones I visit, and I've grown accustomed to the technical answers delivered here. I searched the archives and didn't see it talked about, so I figured better safe than sorry. As I mentioned earlier, 2 of my previous turbo Zs would spin freely at idle, one of these was including a freshly rebuilt one by the same turbo shop...hence why I was worried. And who knows, now in the future maybe someone will encounter the same thing, find this thread, and then be rest assured if mine starts spinning freely at idle. I'll put some miles on it and see what happens. *edit*, also when searching this topic, I found one poster that said he'd seen that happen once where the turbo wasn't spinning freely at idle, and then it seized two days later. I think that also motivated me to create this post. Edited March 19, 2013 by zeeboost Quote Link to comment Share on other sites More sharing options...
ZT-R Posted March 19, 2013 Share Posted March 19, 2013 My new T04Z spins more with a hundred miles on it. Granted it would spin at idle and all but it didnt spin very long after shutdown. After a hundred miles or so it keeps spinning for a while. Give it a few miles and see what happens. Quote Link to comment Share on other sites More sharing options...
ihiryu Posted March 20, 2013 Share Posted March 20, 2013 Pretty normal. My S2000 with a GT35R spun at idle, my RB20 in my Z doesn't spin my HX35. A few of my customers with Supras (2j and 7M) the ones with huge turbos don't spin at idle. I've got a customer with a turbo RSX with a greddy kit and that for sure spins at idle. Quote Link to comment Share on other sites More sharing options...
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