S13 blktop Sr20det low compression - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

shaoyang951 · 05-22-2010, 02:27 AM

I just bought this car not too long ago. Its a bone stock s13 blktop sr20det with a fmic and a circuit-sport downpipe to a nismo cat-delete and a apexi-N1 3 inch catback. I gave it a compression test and it's reading 100psi all across. I gave it a compression test while at cold temp. and running temp. and all the readings came out the same. I made sure all the spark plugs were out, the throttle was wide open during each test and i let it crank at least 4-5 times. My vacuum reading is at around 12psi only during idle. The timing seems to be off and it seems to be choking or stuttering when it reaches around 3k rpm and on but can it be due to my stock internal waste-gate going out because boost seems to spike up a lot on my boost gauge whenever it stutters or chokes??? And can the timing being off contribute to my compression being low???? I did try adding a little oil into each cylinder and after the added oil the compression does jump up quite a bit so is it just my piston rings going out??? Or is it a head warp or my valves??? I don't hear any knocks or clicks. It does take awhile for the engine to turn on when I try to turn it on, it cranks and cranks then it hesitates to turn on. But once it turns on it idles fine and steady at 700rmp. It does not blow any kind of smoke but I do smell gasoline whenever the car is on and running. Please help, I'm new to the Nissan world from the Honda world, thanks!!!!

*fliprayzin240sx* · 05-23-2010, 07:09 AM

If dropping a cap full of oil in each cylinder causes the compression to bump up, then your rings are dun dun...

If you dropped oil in there and it DIDNT jump, then it was something else other than your rings.

BlueDSM · 05-23-2010, 12:10 PM

When you popped out your plugs, were they shiney black and coverded in oil? Or brown/tan coloured and dull?

The only way to really tell 100% if it's your rings (and how f*cked your rings are) would be to do a leakdown test.
Call a few garages, or buy the leakdown tester and do it yourself (you need an air compressor as well). Mind you, if you have burnt valves it'll fail the leakdown test as well, but you'll hear a hissing noise in the manifold.
What's the stock psi supposed to be?

shaoyang951 · 05-24-2010, 02:15 AM

Yea, after the cap full of oil made my compression jump I figured it was my rings but then the timing is off but I don't know how much because I've never touched a timing chain before. The timing was supposedly done by some dummy who used a KA24DE settings instead of settings for a SR20det. This happened before I bought the car, I found out after I bought the car already. But thanks for the input! I have an air compressor just need to go buy the leakdown tester.

nissan240 · 05-24-2010, 02:29 AM

yep most likey your rings are out! and your timing is off. take off your valve cover and look at the two dots on the cams. here you go this should help! btw your car is pretty clean

young

How To Set Crank Angle Sensor (CAS) Timing on the SR20DET Engine

shaoyang951 · 05-25-2010, 01:50 AM

Thanks young, wassup with your ride bro!? i heard you got a beast in your ride! get it up and running. I think I might just either buy a new motor or get it rebuilt. Finally school is over so I have time to check the timing and get it up and running. Gonna prolly get a leakdown gauge and give it a test too. Thanks.

05-22-2010, 02:27 AM	#1
shaoyang951 Leaky Injector Join Date: Jan 2010 Location: Banning, Ca Age: 35 Posts: 129 Trader Rating: (0) Feedback Score: 0 reviews	S13 blktop Sr20det low compression I just bought this car not too long ago. Its a bone stock s13 blktop sr20det with a fmic and a circuit-sport downpipe to a nismo cat-delete and a apexi-N1 3 inch catback. I gave it a compression test and it's reading 100psi all across. I gave it a compression test while at cold temp. and running temp. and all the readings came out the same. I made sure all the spark plugs were out, the throttle was wide open during each test and i let it crank at least 4-5 times. My vacuum reading is at around 12psi only during idle. The timing seems to be off and it seems to be choking or stuttering when it reaches around 3k rpm and on but can it be due to my stock internal waste-gate going out because boost seems to spike up a lot on my boost gauge whenever it stutters or chokes??? And can the timing being off contribute to my compression being low???? I did try adding a little oil into each cylinder and after the added oil the compression does jump up quite a bit so is it just my piston rings going out??? Or is it a head warp or my valves??? I don't hear any knocks or clicks. It does take awhile for the engine to turn on when I try to turn it on, it cranks and cranks then it hesitates to turn on. But once it turns on it idles fine and steady at 700rmp. It does not blow any kind of smoke but I do smell gasoline whenever the car is on and running. Please help, I'm new to the Nissan world from the Honda world, thanks!!!!

05-23-2010, 07:09 AM	#2
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	If dropping a cap full of oil in each cylinder causes the compression to bump up, then your rings are dun dun... If you dropped oil in there and it DIDNT jump, then it was something else other than your rings. __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

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05-23-2010, 12:10 PM	#3
BlueDSM Join Date: Sep 2009 Location: Canada Posts: 4 Trader Rating: (0) Feedback Score: 0 reviews	When you popped out your plugs, were they shiney black and coverded in oil? Or brown/tan coloured and dull? The only way to really tell 100% if it's your rings (and how f*cked your rings are) would be to do a leakdown test. Call a few garages, or buy the leakdown tester and do it yourself (you need an air compressor as well). Mind you, if you have burnt valves it'll fail the leakdown test as well, but you'll hear a hissing noise in the manifold. What's the stock psi supposed to be?

05-24-2010, 02:15 AM	#4
shaoyang951 Leaky Injector Join Date: Jan 2010 Location: Banning, Ca Age: 35 Posts: 129 Trader Rating: (0) Feedback Score: 0 reviews	Yea, after the cap full of oil made my compression jump I figured it was my rings but then the timing is off but I don't know how much because I've never touched a timing chain before. The timing was supposedly done by some dummy who used a KA24DE settings instead of settings for a SR20det. This happened before I bought the car, I found out after I bought the car already. But thanks for the input! I have an air compressor just need to go buy the leakdown tester.

05-24-2010, 02:29 AM	#5
nissan240 Zilvia Addict Join Date: Aug 2006 Location: socal Posts: 690 Trader Rating: (6) Feedback Score: 6 reviews	yep most likey your rings are out! and your timing is off. take off your valve cover and look at the two dots on the cams. here you go this should help! btw your car is pretty clean young How To Set Crank Angle Sensor (CAS) Timing on the SR20DET Engine

05-25-2010, 01:50 AM	#6
shaoyang951 Leaky Injector Join Date: Jan 2010 Location: Banning, Ca Age: 35 Posts: 129 Trader Rating: (0) Feedback Score: 0 reviews	Thanks young, wassup with your ride bro!? i heard you got a beast in your ride! get it up and running. I think I might just either buy a new motor or get it rebuilt. Finally school is over so I have time to check the timing and get it up and running. Gonna prolly get a leakdown gauge and give it a test too. Thanks.