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Discussion Starter #1 (Edited)
Hello,

I'm at a point where I need some help folks. I have a black 2007 Lexus IS250 RWD ("Black Beauty"). I recently took her in for an inspection and the inspector said I am burning a little oil (which was true) and the valve cover gaskets needed to be replaced.

So I accepted the challenge.

I'm decently mechanically inclined. I replaced the water pump, serpentine belt, and radiator last fall. For this job while I had everything torn apart I'd figured I do some other maintenance too, so in addition to the valve cover gaskets I replaced the intake manifold gaskets, spark plugs, spark plug tube gaskets, ignition coils, and the three small rubber gaskets inside the VC (two that look like little "8"s and one is a standard circle). When I put everything back together I had some oil SPRAY out of the driver side banjo bolt because I forgot to tighten it all the way (it's tight in there). Oops. Spilt a lot of oil on the engine, but after I tightened it back up no more oil spewing at least. I turned her on and no oil spills, but... there was smoke coming from underneath the driver side valve cover area, looking like it was coming from the exhaust manifold.

Crap.

I must have overtorqued the gasket and crushed it, or it's not seated properly and oil is dripping onto the exhaust. So I tore her apart again. I bought new VC gaskets (just in case I crushed them). I bought the Toyota 103 sealant and made sure I dabbed that in the corners. I borrowed a torque wrench to make sure to tighten the bolts to the proper spec, using an X tightening pattern starting from the inside going out. 50% spec torque on the first pass, full torque on the second pass (15 ft-lb for 12mm and 7 ft-lb for 10mm). Got her all buttoned back up. Feeling pretty darn good about myself. Then, smoke again. @#$%^&!

So, I'm not sure what is going on. Below are links to videos of the smoke both from above and below. As you can see when the fan is on, it is not even noticeable (very beginning of topside video, you can hear the fan running). I don't see anything dropping onto the exhaust. There's not really any smoke until the engine comes up to operating temp. Then it gets worse/heavier when I redline her. After I stop and she idles for a while, it slowly returns back to a smaller trickle. At this point I'm stumped and pondering my next actions.

What a freaking journey. SO, where to go from here?

1. Could it possibly be just excess oil from the 2021 banjo bolt incident and it's burning off the 2L of oil I spewed over the engine? I'm not sure. I ran her pretty hard for about 30 minutes, mostly in 1/2nd gear at about 5-7k rpm. Then I slowed down and ran her gently for about 15 minutes after that at grandpa pace. I feel like any oil would have been long burnt off, and additionally there seems to be a correlation between rpm and the amount of smoke being generated. So I don't think it is excess oil but not ruling it out entirely. Maybe I should spray the area down with degreaser?

2. Did I really muff the valve cover gaskets a SECOND TIME?! I sure hope not, but that is certainly not out of the question. It REALLY doesn't look like any oil is spilling down. I even took my telescoping magnet with mirror attachment and ran it across the underside of the VC flange while she was running, just to see if any oil dropped onto it or if I could notice any leaks.... and nothing. Bah.

3. Could it be something PCV or exhaust manifold/gasket related??? Would an exhaust leak create that kind of smoke?? I'll look up some diagrams for the exhaust system later but it looks like it could potentially be a bad gasket between the exhaust manifold and the engine (?). Or maybe a crack in the manifold itself somewhere?

4. Any other ideas of what it might be? I'm stumped and don't really want to bite the bullet and take her into a mechanic/stealership yet.

Any assistance would be greatly appreciated. Thanks.

Cheers,
Armor

Videos (let me know if these don't work - videos are huge and I'm sharing via Google drive):

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Discussion Starter #2
Update: I started her up and let her idle in the driveway for about 2 hours today... not a single poof of smoke. But then I took her for a short drive up and down the road, mostly in first gear. Pop the hood and noticed the smoke started again.
 

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I usually put RTV on the whole gasket. Just a film. I never used a torque wrench for them. Just good and snug. I think the Spec is in Inch Lbs. Not Foot lbs. But it has been several years away from the book. It could still be leftover oil. You could clean the engine bay with de-greaser and wait to see if it comes back again.
 
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