So, car has been fine for a couple/few years since parts went on and tuned.

A while back, got some misfires on the Aeroforce gauge. Put in one-step colder NGKs, everything was gravy.

Then, I was occasionally hitting limp mode. Finally checked the evap solenoid, and sure enough, bad. Replaced it.

Then, throttle body codes. Research says sensor went bad. Replaced whole thing, life is back to good.

Then, I started getting some flutter from the turbo. Instead of the kicked puppy bark, under low load pulls I would get wa-wa-wa-wa-wa, and under heavier pulls I'd get a good bark and then wawas.

Pull the Forge BPV, needs greasing. Also, one of the o-rings was shot. Got a new internals kit for the BPV, and did the business. In the meantime, I had put the stock one back on....and was still getting flutter wawas. Hmm...

Fast forward to now; I've just been living with it. But now, I just noticed that a medium 2nd gear pull is causing white smoke, and the Cyl2, Cyl6 (haha) are both pretty consistently reporting misfires on the gauge, but the only CEL code is the turbo flutter (P02261).

So, when I can, I think I'm going to (finally) clean the intake filter, check the plugs again, make sure things are tight including that stupid IAT2 sensor, and clean the MAF.

Any other recommendations or insights?

 

First recommendation is put stock plugs back in immediately

 

That's the first thing I thought, never put in colder plugs.

And maybe clean your intake valves.

 

So, paying better/closer attention to the smoke, it specifically happens in 2nd, after I accelerate, when I let off the gas and the engine slows the car down. Makes me think more plugs/wires and injectors need checking.

I'm still going to do all the other maintenance, because it's just best practices.

I'll look at putting the stock plugs back in, or getting new stockers. But why say never go colder? I've seen plenty of recommendations for these exact NGKs when tuned.

 

Don't know why, but every tuner I've spoken with says to stick to the stock plugs.

 

Filter cleaned and re-oiled. Plugs pulled and cleaned. MAF cleaned.

Still same behavior.

I'm dreading this, but time to check the oil, and see if there's coolant in it...

 

No coolant in the oil! Thank God...

Pulling the NGKs again.

WHY THE HELL ARE TWO OF THEM GAPPED TO 38 AND TWO OF THEM AT 40+ ?!?!?!?

Sonuva...

 

Ok, regapped all of them down to 35, and swapped 2 & 3.

If gap was the problem, everything should be fine.

If the #2 plug is the problem, then the issue should move to Cyl3.

If it's the wiring or injectors, the problem shouldn't move.

 

Still no change. My recorded misfires MIGHT be lower, but Cyl2 still increments by 1 every few seconds when sitting idle.

As general maintenance, and because I needed gas anyway, I dumped a bottle of Lucas injector cleaner in there, but the results from that will take time.

Watching the smoke more closely, it only happens when I get into boost, and can happen in any gear (at least 2nd and 3rd). Even 3psi, once I let off, will make smoke. If I stay out of boost, it doesn't happen.

Cooling off the engine now so I can get in there and pull the Forge BPV again, and see if anything is obviously wrong. Upside is, P2261 hasn't come back since I cleared it for the first drive of the day, and I've made a few trips, done a few pulls to check smoke, etc. So for now, P2261 is gone.

Things done so far:

Cleaned and re-oiled the air filter.
Cleaned MAF.
Cleaned and regapped spark plugs.
Dosed fresh tank of gas with injector cleaner.

 

Did more reading. When I pull the BPV, I'll also take off the intake and see if I can see anything with the turbo, like shaft play or oil or anything.

It really seems turbo-specific (only happens after boost).

 

stock plugs only. the DI engine is finicky with anything else

 

dude if i were you i'd just order some new stock plugs and throw em in

 

A bit of oil on the intake side of the turbo. A bit more than I like. And, since I have a catch can, why the hell is there oil on intake side?! So I pulled the can, and nothing in it (at least not enough to drain). Cleaned the "wool" and all the pieces, and put it back. Double checked the lines, no cuts, kinks, or other badness.

And it still does the thing.

Checked the turbo shaft, and there was a tiny tiny bit of side to side play, but the reading says that's ok.

 

There are a lot of guys on here that have tried all kinds of plugs, the tc pretty much hates everything but stock. I myself tried one step colder and my car ran like **** just like urs is. Trust us in this one, put the stock plugs back. If they are bad, get new ones. Ur car will thank u

 

I run 28-30 psi on zfr with meth, and also sometimes without meth, if I run stock plugs then there is no reason for u to change urs from stock

 

Lol u sound new here even with senior status. Let us clue u in on a few things with the lnf. Stock plugs only, u notice pretty much everyone saying that. Catch cans don't work, at all, u need Powell oil separator. Which will run u 400 but it is the only thing that has proven to work keeping oil out of pipes and intake. Next, pull ur intake manifold and walnut blast ur valves, bet that will solve ur issues if u do those things. Don't walnut blast before u have a oil separator or ull just have to do it again. This is the best advice ur gonna hear from us, if u don't listen, enjoy ur new car and it's issues.

 

Gee, thanks I guess.

I'll put the stock plugs in tomorrow, and see if the misfires go away.

But that's not going to help the smoke issue. The more I research it, the more it looks like it will be a blown (or on its way) turbo seal.

Also, I could give a squirt about it saying I'm a Senior Member here...probably just goes off time since registration. I've had the car for five years, and the NGKs have been in for at least one year, maybe two. This is the first time the smoke thing has happened, and aside from that I've had no problems that weren't solveable and somewhat expected (evap solenoid, throttle body sensor, etc).

When I got the catch can, it was the "recommended" thing. I don't think the Powell oil sep even existed at that point. *shrug*

 

well smoke issue does seem like something is blown in there. im assuming u never walnut blasted, im sure that's ur misfire issue. ya in the beginning everyone recommended a catch can, then we found out they don't work. I had mine on for over a year and not one drop of oil was in it. even with wire mesh in there so oil couldn't just get sucked though. have u not been on in awhile? definitely get the separator. ull thank urself. but if u do make sure to take all pipes and intercooler off and clean them cause u can bet they got decent amount of oil in there.

 

and sorry if I came off pricky. lol bad day yesterday working on the balt. lol

 

I recently walnut blasted my cobalt last summer. It's worked for a while and the idle was smooth. Now I'm getting the slight misfire in third cylinder again. At this point I figure it is my injectors. Car still haul ass and no smoke.

I would by Powell oil separator but 400 is to high for me. I can put that towards my timing chain kit.

 

400 is to high to have no oil ever in ur pipes again and not have to walnut blast again? Well I guess that's ur choice .

 

⬆️ This, cobalt guys are so cheap

 

Haha some, I wish I was cheaper with the Balt. I even refuse to put used parts on it lol

 

So does it smoke all the time? If it only smokes a little then you start to build boost it is most likely either buildup of oil/gunk on the intake valves and runners, or something has changed with your car from when it was tuned (boost leak, maf issues, map issues), and I'm just going to steer clear of who your tuner is

Pretty much.

 

It only smokes after I get into boost and let off. Reading & research says this is classic blown turbo seal.

I wonder if this was starting to happen about the same time I got the flutter, and couldn't get rid of it even with a stock BPV....hmmmm.

Well, today at least I was able to do something: rotors and pads came in! So front rotors and pads done (rotors were warped), rear rotors I bought just for grins, and I'm waiting for the rear pads to ship. Got that stupid little cube tool for the backs, and so they'll be done soon too.

Ran around looking for someone to walnut blast in Las Vegas...everyone looks at me crazy like duh your valves don't get dirty, duh, we use ceramic media, duh we gotta take the whole head off, you'll need a new head gasket, the job's 1600 bucks and I'm just like FFUUUUUU...

I'm gonna end up getting the toys to do it myself from Harbor Freight, unless I can get a hold of the guy on the bimmer forums. He's local, said FU to his stealership wanting $1k for the job, and he's done a bunch of cars now. The work looks gorgeous, but I have to hope and pray the BMW intake port adapter thing fits the LNF as well (it won't, most likely). But at least he has the tools to do the business, if I can find or fab an adapter.

In other news, I suddenly have a fair bit more carbon on my garage floor behind my tailpipe....and no more misfires. I wonder if there was carbon causing the issue that finally got chewed up and spat out. *shrug*