1jz vvti compression check

[Options13]

so, my car is burning oil and it's driving me crazy.. it came down to the valve seals or the piston rings..

The car puffs oil out after the end of revs, and on decel, even the slightest blip of the throttle would puff out a little smoke. Its defiantly oil.

anyways i did a compression check tonight and came across 120psi on all cylinders.. i thought it was rather low, and though maybe the compression tester just reads low.. BUT i did add oil to one of the cylinders to see if it would make a difference. I repeated the test on the cylinder i added oil into and the tester read much higher, like 180psi.

i didn't continue on the rest of the pistons because of anger, but by doing this test, are my rings fried?

all the cylinders are consistent at 120psi.




at 1:30 you can see the smoke on decel, while its on the dyno.

S14 1JZ DYNO RUN by John Reed - YouTube (http://www.youtube.com/watch?v=z1BqUlsjXww&feature=c4-overview&list=UUCtLzg1wRhZXtWyZVQfc2hQ)


the car did 310whp with stock turbo at 15psi.. which confuses me if the rings are so shot, IF SHOT..?

[hashim]

rings, more than likely, the oil helped seal the CC and thats why your compression went up, if it was valves it would still read low.....just my thoughts

[Jesus_lopez405]

My money on rings !! Have you checked our spark plugs ?

[fliprayzin240sx]

Rings done...did you check the minimum acceptable compression for 1JZs? Nissan is roughly 125psi.

[Options13]

damn, it's just crazy because the motor had very low miles when i got it, and was super clean.. i guess its a good sign all the cylinders are consistent though.

[S13project]

Had similar issue with my SR. Car was spewing smoke on decel. Turned out to be turbo going bad.

[Options13]

I already changed out the turbo, and it still doing the exact same thing.

[brndck]

A leakdown test should confirm that it's the rings. Adding oil and seeing the number jump is a pretty good indicator of rings not sealing.

[Options13]

With my compression being as low as it is, shouldn't i be blowing oil out my valve cover and oil dip stick tube? I should be getting a shit load of blowby.. but i'm not? hmm..

very confusing, and i don't exactly know where to rent a leak down tester, and been too lazy to make one..but i may end up doing it.

[sterlinge]

Do you have a restrictor for the feed line? I would use one. You could also have a pinched drain line. If you dont have blow by I doubt its the rings. Maybe the valve seals. A leakdown test will tell you the condition.

[Options13]

yup, have a restrictor, the tomei turbo came with one, and the drain line isn't pinched. I'm just gonna attempt a leak down test and see whats going on. i'll keep you guys updated.

[landins13]

Your compression is low but not so far gone as to cause the dipstick to blow out. My VVTI 1j is between 155 and 160 across the board.

The sr i got rid of for this engine would pop the dipstick out but it has over 30% of blow bye on all of the cylinders.

[FutureFab]

I had the same issue. Turns out it was the turbo.

Did yours smoke with stock turbo and tomei turbo?

[brndck]

I already changed out the turbo, and it still doing the exact same thing.

I had the same issue. Turns out it was the turbo.

Did yours smoke with stock turbo and tomei turbo?

Reading. It comes in handy on the internets.