Sr20det 50trim low compression but car runs perfect, HELP please - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

BOOSTALOT · 03-13-2013, 11:23 AM

Here i go with my story please try and understand my case

well i recently went big turbo on my sr20det
motor was bone stock (ran perfect) so i pulled the head and had it resurfaced, added a cometic 1.01mm thick, ARP headstuds, and Isis rocker arm stoppers to reinforce the motor. got it street tuned with a power fc and i set the boost at 15psi and the car ran like a champ. (Ran it like this for about 2 weeks)
before i got to take it to the dyno to get professionaly tuned i started noticing some smoke on my passenger seat whenever i would get on it and it honestly smelled like oil. i went ahead and pulled over immediately and checked under the hood, my shitty ebay catch can was dripping oil and my dip stick had blown out of its place. i fgured i had too much compression and was spewing oil on my turbo causing the white smoke. i went ahead and changed my catch can to a bigger unit with bigger entries..it's routed from the front of the pcv<catch can<atmosphere

Once I got it changed I took it for a nice run and noticed the smoke inside the car. I took it to my local shop and popped the hood and found the catch can had filled up..I thought to myself that maybe I had put to much oil in the car and was causing blow by..anywho I drained it and got back on the road to see anything would change, did a couple pulls then pulled over to see That the catch can had once again filled up! (1 quart catch can)
I start flipping shit and take it to the shop that did all the work on the car and the check compression and it shows
110,150,150,150.. These guys now tell me that my piston rings might be bad so I flip shit at these guys and tell them why they didn't mention to me before i went big turbo that should i should have changed the rings when the motor was apart...
The reason why I did t think about the oil rings or anything was because they told me that this motor is bulletproof and with 75,xxx miles there is no need for anything, just the headgasket and arp head studs (I come from a srt4 so am a noob to this motor and as to how much power the stock motor can handle, this is the reason why I took it to a shop)
Now I'm here with a perfectly running car (no smoke at startup, idles perfect, pulls great, lowered to 7 psi)
And a brain filled with ideas of what could cause this..I'm scared to drive the car because I don't to cause any damage!

Maybe I'm ignorant and don't want to face the matter that I may have to pull the motor and get it rebuilt, so before I have to do that I would like to see if maybe by any chance it could be something else causing this low compression on cylinder 1...(pcv valve, too much oil in motor, valve stuck open?? Etc..)
Where should I start?? What to do?

ANY AND ALL THOUGHTS ARE WELCOME!
Please help!!!

Thank you in advance!

03-13-2013, 11:23 AM	#1
BOOSTALOT Join Date: Dec 2012 Location: Winter garden fl Age: 31 Posts: 33 Trader Rating: (0) Feedback Score: 0 reviews	Sr20det 50trim low compression but car runs perfect, HELP please Here i go with my story please try and understand my case well i recently went big turbo on my sr20det motor was bone stock (ran perfect) so i pulled the head and had it resurfaced, added a cometic 1.01mm thick, ARP headstuds, and Isis rocker arm stoppers to reinforce the motor. got it street tuned with a power fc and i set the boost at 15psi and the car ran like a champ. (Ran it like this for about 2 weeks) before i got to take it to the dyno to get professionaly tuned i started noticing some smoke on my passenger seat whenever i would get on it and it honestly smelled like oil. i went ahead and pulled over immediately and checked under the hood, my shitty ebay catch can was dripping oil and my dip stick had blown out of its place. i fgured i had too much compression and was spewing oil on my turbo causing the white smoke. i went ahead and changed my catch can to a bigger unit with bigger entries..it's routed from the front of the pcv<catch can<atmosphere Once I got it changed I took it for a nice run and noticed the smoke inside the car. I took it to my local shop and popped the hood and found the catch can had filled up..I thought to myself that maybe I had put to much oil in the car and was causing blow by..anywho I drained it and got back on the road to see anything would change, did a couple pulls then pulled over to see That the catch can had once again filled up! (1 quart catch can) I start flipping shit and take it to the shop that did all the work on the car and the check compression and it shows 110,150,150,150.. These guys now tell me that my piston rings might be bad so I flip shit at these guys and tell them why they didn't mention to me before i went big turbo that should i should have changed the rings when the motor was apart... The reason why I did t think about the oil rings or anything was because they told me that this motor is bulletproof and with 75,xxx miles there is no need for anything, just the headgasket and arp head studs (I come from a srt4 so am a noob to this motor and as to how much power the stock motor can handle, this is the reason why I took it to a shop) Now I'm here with a perfectly running car (no smoke at startup, idles perfect, pulls great, lowered to 7 psi) And a brain filled with ideas of what could cause this..I'm scared to drive the car because I don't to cause any damage! Maybe I'm ignorant and don't want to face the matter that I may have to pull the motor and get it rebuilt, so before I have to do that I would like to see if maybe by any chance it could be something else causing this low compression on cylinder 1...(pcv valve, too much oil in motor, valve stuck open?? Etc..) Where should I start?? What to do? ANY AND ALL THOUGHTS ARE WELCOME! Please help!!! Thank you in advance!