View Full Version : Blown piston rings?
THEminusMAN
05-02-2010, 05:55 PM
The easy answer to what I'm asking is "do a compression check dummy!". I will, tomorrow but maybe this is normal. I have intermittent power, when i apply the throttle the car boosts well, then 30 miles into my drive i would hear a rushing of air noise and loss of power when under boost. It still has power just not the push me into the seat kinda power. So i have been pulling over and tightening and adjusting hose clamps and have been able to get the POWER back, but then sooner or later Its the rush of air again. The real problem here is im wondering if my rings are bad: To fix my leaking pipes once and for all I sealed the intake part of the turbo and applied some compressed air and watched my boost gauge, i got it up to 8-9 psi and my dipstick popped up and air rushed out. Is that normal? I could watch the boost gauge dive when the air rushed out my dipstick tube. That would have to be my rings? Thanks for any help anyone can be, im not too enthusiastic about the idea of tearing this beach down and throwing in new rings, ...
95 s14
s14 sr20det (6-7 psi)
240sx fuel pump (i know, fail)
240sx fuel filter
THEminusMAN
05-04-2010, 07:58 PM
Compression test showed 125 on all 4 cylinders. Im thinking this may be a fuel issue, I changed out the stock ka24de fuel filter for a z32 TT filter and it seems to run better, the odd thing was barely any fuel came out of the line when I pull it off the stock filter. Please let me know if 125 sounds too low, I googled it and the world seems split on whats a good compression psi...Thanks.
slim_240
05-05-2010, 10:14 AM
145-160 psi imho is perfect
obsolete
05-05-2010, 11:03 AM
I got the same problem. Boost holds fine, but don't feel the power. my compression was 120 on all 4. did the test where you put some oil in the spark plug hole and didn't raise the compression any more. s14 sr20. wondering why compression is so low.
slim_240
05-05-2010, 10:02 PM
hook up a vacuum gauge and leakdown testerrr
732sr20det
05-06-2010, 08:44 AM
Well i felt like i had a problem with that befor with my old s13sr. It would be fine then just felt like i lost power, it would boost fine. I would pull over mess with my bov cheak stuff like it would feel like a big boost leak. but everthing was fine i did boost leak tests i was pretty good. I did a compresion test one day to have some un happy results 100, 100, 85 ,100 in that order very upsetting then then not to much longer it finialy blew up so if i were you i would do a leak down and see were its realy coming form why its like that. 120psi is low to have in all cylinders.
Ceepo
05-06-2010, 11:02 AM
Change you pcv possibly.
PCV Valve—Positive Crankcase Ventilation (PCV). The PCV valve acts as a vent to the upper engine removing excess combustion gases via vacuum lines that plug into the valve. A dirty or restricted pcv valve and cause excess pressure on internal oil seals and gaskets.
THEminusMAN
05-08-2010, 12:18 PM
I think i have the answer to my issue. 120 though low isn't a done motor in need of rings In my uneducated opinion. I developed a new issue yesterday which prompted me to panic a little. I started hearing a noise which sounded kind of like a card in bike spokes when my turbo would spool up. Its tone would change in relation to the increase in revs on my turbo. I googled a bit and then dug into the turbo fearing my turbo had sucked in something. Turbo fine, just LOOSE FKN NUTS on my turbo are letting exhaust leak out between the turbo and the manifold. The noise i was hearing was probably exhaust pulses escaping. I had the metal retainers bent down to stop their rotation but apparently its fail and they spun loose anyway. Im glad i got this figured out, but not ready to try to tighten these... as we all know they're in a tight spot. Hope this helps anyone else out there.
THEminusMAN
05-08-2010, 12:21 PM
God forbid the gasket is burnt out.....if i have to drop this turbo im going to snap.
THEminusMAN
05-08-2010, 12:50 PM
And i know that 120 is low and should be changed, but its definitely not the reason it was giving me issues, and still runs very well and will probably make it till winter (when i will pull the motor for rebuild and probably go top mount...
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