Worn Rings?

[Trist89]

Hay guys,

bit of a newbie at this stuff.

Symptoms: Small amount of white smoke coming from exhaust on idle.

Smoke smells of burnt oil and is thin (can only be seen infront of light source.)

Stalls when coming to a stop (at lights etc) at low revs.

While my exhaust or whats left is a basically a straight pipe leading from dump. Last compression test 6 months ago brought up a consistant 125psi(approx) in all cyl. Good or Bad??

Iam running lubrimaxx sports plus and Lucas heavy duty oil treatment...

Shell V-Power is used every tank.

I have been told by friends that worn rings is the cause of the smoke, however oil pressure is same as always (never below 25psi) and the car has not been tuned for straight pipe yet. Is this true or am i just being worried for no reason??

Any advice would be much appriciated.

[Moodles2]

R32 GTR Nissan service specifies 121psi is the bottom limit for RB26 cylinder compression, RB20 would be close by but not sure of the exact figure. It could just be the oil you are using (never heard of Lubrimaxx before) or the oil + oil additive combo.

What weight is the oil anyway?

[blind_elk]

Oil pressure is not controlled by the condition of the rings.

A simple way to test the rings is to do a compression test, then add a bit of oil to the cylinder (through the spark plug hole) and repeat the compression test. If the rings are worn, you will get a higher compression with the oil. Also make sure you do the compression test with WOT.

[Trist89]

Lubrimaxx sports plus is 25/60. The 20 has done 170 000km. Oil is changed every 5000.

[blind_elk]

25/60 is WAAAAY too heavy for a RB20 engine. The Nissan spec is 7.5W30. You should be using something like a 0W40, 10W40, 10W30.

[Trist89]

What do you think about penrite sin15. Just not game to go as thin as 7.5w. Work in auto parts so can get the stuff cheap. I do value all advice. Keep in mind car has done 170K.

The car only blows smoke once car has been driven for longer than 10mins, and only for a few minutes, before no smoke is visable.

Keep replies coming.

[Moodles2]

0w-40 or 5w-40 are preferential in my opinion, though 10w40 is ideal for summer. Sin15 is fine though, 15 is a a much better cold rating than 25.

The smoke might simply be solved with a oil catch can, if blowby is recirculating lots of oil through the breathers

[Trist89]

True, Ill have a look at what the Five R ones are worth tomorrow at work, along with the some 10w sinthetic. Cheers for the help.

[blind_elk]

What do you think about penrite sin15. Just not game to go as thin as 7.5w. Work in auto parts so can get the stuff cheap. I do value all advice. Keep in mind car has done 170K.

The car only blows smoke once car has been driven for longer than 10mins, and only for a few minutes, before no smoke is visable.

Keep replies coming.

The "7.5" (or whatever the first number is) is only really related to cold starts. It is an indication of how quickly you can get lubrication to all the parts of the engine. The lower the number, the faster you get lubrication. So a "10" is better than a "15" for cold starts, and a "5" is better than a "10".