D15B vtec Single slow.

So when the car is complelty cold, I will get in the car start it up and it will shoot out a cloud of greyish smoke, then stop.

On higher RPMS the car will smoke, on downrevs the car will smoke.
I have to keep putting oil in her.


I have replaced the valve stem seals.

What do you think it could be ?

 

If it smokes when you get on it, and smokes when you let off the gas. Sounds like bad piston rings causing blowby. Not to hard to fix if you have the tools and know what you are doing.

Nick

 

^x2. I have experienced this before.

 

That is what I am thinking, piston rings for sure.

ok We have almost established that.

Now, Here is my plan. Im going to take the motor out, and while replacing the rings, Im going to do a nice hone, and replace the bearings. Should still use standard bearing,right ?
When buying Rings, do they alwasy need file fitted ?

 

(Guess I should have performed a leak down test in stead of being lazy)

 

Leak down? You can do a compression test. Do all 4 cylinders. If you have varible readings, put like a cap full of oil in the chamber. (will not hurt anything just dont put in too much) then re-do compression test. If it is rings then the readings will be alot better.
As far as bearings go. They are color coded from honda. So I would mic the crank and rods, do the math to figure what bearing you want for X clearence. (the block also has stamps to tell you what they used from the factory, but mic em to be sure.)
You MUST re-hone the block before installing rings. Really it should be bored and oversized pistons put in. But you can just hone them, you just run the risk of the cylinder wall being out of round...

Not all rings need to be filed. You need to measure those too with feeler gauges at the top, middle and bottom of the cylinder wall.

Nick

 

Usually if it smokes on hard acceleration it is caused by bad (worn-out or stuck in the ring lands) oil control rings. If it smokes on decel or just a puff when first starting it is usually oil going past the valve guides. You said you installed new valve seals which would be fine assuming guide clearance is OK. If you have excessive guide clearance new seals are going to leak. The reason it smokes on decel is because when the throttle is shut and the rpm is high there is extremely high manifold vacuum which sucks the oil past the guides. The reason it puffs oil when first started is because after it sits any oil that was above the valve guide just drains out into the intake or exhaust and burns when it is next fired off.

A compression test or leakdown test isn't going to tell you anything about your oil control rings. You could take them out and have better than normal readings (similar to doing a wet compression test). If you are going to do the rings anyway I would highly recommend at least having valve guide clearance checked or just have a valve job done.

 

Compression tests tell you alot about the inside of the motor. And the vacum on deccel can also pull oil right past your rings. Valve seals can do this also, but if he replaced them then I doubt it is the issue.
Pull the pistons, I bet there is vertical scares on the cylinder walls and the rings are probably stuck to the pistons.

 

Yes, a compression test can tell you a lot about of your compression rings but nothing about your oil control rings. He could have perfect compression and still have bad oil control rings. Although compression rings do scrape some oil from the cylinder walls it is not their primary job. That is the job of the oil control rings which do nothing to seal compression.

My point about the valve seals was that if his valve guides are sloppy and the valves are allowed to **** to one side the seals are not going to work and oil will get pulled past the guides. In that case new valve seals would just be a band-aid.

 

I thought it could be valve guides as well...

Im trying to figure out what i want to do, do a head job, rings and bearings or just get an B18B1 or B18a1.....

 

i have the exact same issues as well. smoking and i have to add oil all the time but the motor is still running strong. i'm going to replace the valve stem seals first and see if the burning oil stops but if it's still a problem i will replace the piston rings which i've never done before - quick question, can i take out the pistons without having to take the motor out of the car?

 

Yes, Take the head off, unbolt oil pan windage tray rod bolts and push the pistons out through the head.

 

Which is one of my points. If the engine is running strong it likely does not have low compression and a compression test isn't going to tell you about about any oil control issues. A compression or leakdown test tells you of the condition of the compression rings, not the oil control rings.

 

my car used to do that. =\ . just swap it ! haha