TallTim

iTrader: (2)

Hello Fellows, here is a puzzler you can help with?

Recently installed new complete alum heads, ZZ4 cam, 1.6 rr, kept the TPI

I have smog delete, EGR delete, shorty headers, no cat.

Car starts right up and idles great. Once warm at around 200 coolant temp the blue smoke starts. Engine does not misbehave during the smoking.

Plugs are clean (and new).

I am not throwing any codes, BLM is at 123. O2 is bouncing around b/w .3 and .8. Fuel pressure at idle around 45.

PCV rattles, new hose PCV to plenum. Other hose valve cover to throttle body in good shape.

The engine probably has less than an hour runtime on it from some short drives around the hood.

If I let it cool down and start it again the smoke is gone until it gets warm again.

I figure it's not the valve seals or it would smoke on start.

I figure as the temp builds or just with enough runtime an oil leak into the combustion chambers starts.

I was thinking of disconnecting the ypipe at the headers and seeing if it was just one side or the other.

Any thoughts? Thanks!

el_muerte

I'm a bit confused. You said the engine has less than an hour runtime on it; is it a fresh rebuild or do you mean an hour since you put the new heads on?

If rebuilt, did you follow break-in procedure? If old shortblock, I'd guess the rings are worn... try a cylinder leakdown test. Your spark plugs won't show carbon buildup from burning a bit of oil over an hour.

TallTim

iTrader: (2)

Sorry not clear. The short block is stock, 100K mi. It was not smoking when I took the top end apart. I did my best to keep junk out of the cyls and kept them lightly oiled while I had it apart.

I get what you are saying about the leakdown test. But if the rings are worn wouldn't it be smoking from startup? Thx.

el_muerte

Smoking from startup is usually due to valve seals allowing oil to pool in the cylinders with the engine off.

TallTim

iTrader: (2)

Update...

In pursuing El's suggestion that I should do a leakdown test, I decided to drop the y-pipe to see if I was chasing at least one bad cylinder on each side or just one side.

Hmmm she smokes only from the pax side. And before a complete warmup (but not from start.) OK so I have at least 4 good cyls...

Since I don't have a leakdown tester yet I though let me pull that rocker cover and see what's news there.

Lo and behold that back cyl had the intake rocker nut backed off and the rocker was off the spring. OK progress. I've had to hammer those nuts to tighten them before. Let's do that.

Not sure the inop intake valve would be causing the smoke, so tomorrow when I fix that and let it idle a bit we'll see. I'll post back.

If you have the means, I highly recommend running open headers for a bit. Even at idle...

TallTim

iTrader: (2)

Yes that was it. I believe the intake stroke pulled oil up from below since it did not get an intake charge from the intake valve which was not opening. Then on the power stroke the lack of combustion did not force the rings against the wall letting more oil up.

Anyways thanks for the help.