Smokey at startup

[parasolution]

90 240SX stock - 181,000 miles

As the title states, the car is a little smokey at startup. It blue smoke, thus I assume its too rich. But once it warms, its all clear. I also just had it smogged and it passed with flying colors; but the technician said it was dirty at the start of the test, but it cleaned up as the test progressed.

Even though it runs well and passed smog, should I be concerned about the blue smoke.

[KA_240sx]

The car is burning oil on startup. If it was running rich it would be black smoke.

have all of the seals been replaced? rings? the engine does have quite a lot of miles on it.

SEAFOAM it.

[x240xdrifter]

this is actually quite normal, your car has 181,000 miles correct? well your cyclinder walls are worn out from normal engine use/ so many miles, so your piston rings will not seal properly till the engine warms up, and the oil coats the rings properly, the only real remedy for this is to overhual the engine, and I don't know what you would want to do about that but as long as your not getting blue smoke constanty, you'll be fine

[b_rad]

do a compression test.

[parasolution]

this is actually quite normal, your car has 181,000 miles correct? well your cyclinder walls are worn out from normal engine use/ so many miles, so your piston rings will not seal properly till the engine warms up, and the oil coats the rings properly, the only real remedy for this is to overhual the engine, and I don't know what you would want to do about that but as long as your not getting blue smoke constanty, you'll be fine

That's what I figured. I'm not too worried about it, as the car still runs very well. I'll probably get around to doing a compression check.

First, I just need to remove the clutch fan and install an electric fan.

[drmerdp]

Could certainly be the rings as well, but I'd say its the valve seals. when the seals heat up and are re drenched in oil they expand and seal better.

Rings mess with compression and blow by more then, causing smoking.

[parasolution]

Let me ask this.....back in the day, my dad used to tell me to add a heavier oil if the car is old and is starting to burn oil. He would switch to 20-50.

About 2 years ago, I took my car into a shop (Nissan only) and the mechanic said I should lighten the oil, to a 10-30. He said the car will be much happier for it, as the engine doesn't have to work as hard through the lighter oil.

Whats the general consensus on oils and high mileage engines.

[x240xdrifter]

IMO, 10w30 is thick enough for high mileage cars