Heavy oil smoke at stoplights?
 

What's up ya'll. I recently put a turbo on my 94 1.8L and all was well until I did an oil change about 2 weeks ago.

When I'm driving the car, nothing happens, it acts like it should. However, if I leave the car running while I go into a gas station, or if I sit at a redlight for too long, I fog the area out with oil smoke.

If I rev the car to 1,500 to 2,000 RPMs and hold it, the smoke lasts another couple seconds, then goes away. It doesn't come back while I'm driving, only when sitting at red lights and the car is idling.

Has anyone ever encountered this problem? Or maybe have some insight into where I should start looking to fix it?

The first thing I would do is check my intake manifold and see if it is filled with oil. It sounds like you're pulling oil into the intake under heavy vacuum. You may need a better breather and catch can setup.

Thanks Ryan. :)

I'm running a breather filter on the driver's side of the valve cover, and have the PCV disconnected, with a plug on the intake manifold port for it. The PCV and line are still dangling from the passenger side of the valve cover.

Can't see if you have a signature on mobile. What turbo are you running? Are you using a kit? How big is the oil drain from the turbo?

If It is a used turbo you may have bad seals but that should still smoke when you're driving. You might also want to check the spark plugs to see if any one of them is fouled with oil indicating a leaky valve seal.

New T28 .60ar, homebrew / eBay ~1,000 miles. Oil drain is from Begi, drops straight down into the pan. I'm going by the shop when my radiator shows up today, so I'll pull the plugs when I get there and let you know.

Pulled the plugs, they're good. 1,000 miles on them, no signs of fouling. I plugged the PCV back in. So far, no more smoke.

If naturally aspirated, that's a perfect description of leaky valve stem seals. If it isn't that, check the outlet of the turbo's compressor to make sure it isn't putting oil into the intercooler.

I had same issue, car was smoking oil on red light.

Intake piping was clean and so was the spark plugs.

Turbo seals were shot and was leaking oil on the exhaust side.

Intake valve guide seals are my bet . Fredb

Sixshooter, it's turbo.

Pacheko, it only leaks after sitting idle for a solid 120+ seconds. Then when I rev it, the smoke goes away. Turbo is 1,000 miles old -- still think it's the seals?

FredB, that's the direction I'm leaning right now. My buddy owns a shop and thinks it's either overfilled with oil (touching the F line on the dipstick) or valve seals.

What happens if you run down hill throttle closed , ( high vacuum ) then accelerate away ? I'd expect a turbo seal to cause smoke all the time especially off idle where the oil pressure is higher but still not in boost . Still it's odd that the plugs aren't showing any sign oil if it's going through the combustion chambers. Fredb

I'll have to find a hill. Those are rare in Florida. ;/ I'll head out to a bridge on the interstate tomorrow and check it out.

It's got me stumped, too. I've had a 95 Eagle Talon that had bad turbo seals, and it smoked all the time, getting progressively worse until the turbo needed to be rebuilt.

If it's coming from the turbo I would guess that it's not happening while under load because there is pressure on the front side of the seal from exhaust gasses or intake air. This could be caused by an inadequate or kinked oil drain, feeding too much oil into the turbo, or excessive nose angle on the turbo. None of which would require a bad seal.

Where is Florida are you located?

I went down a hill multiple times, at the boost gauge read 27-28 inHg, but no smoke came out of the back.

Ryan_G, I'm outside of Jacksonville.

It will be Tuesday or Wednesday before I'm able to get into the shop and pull the coupler to check if turbo is making it's way into the intercooler. When I pulled off the TB / IC coupler the other day, there wasn't any oil on that side.

If there was no smoke after getting back on the throttle, that pretty much rules out valve guide seals . Got me stumped.

Aye. Got me stumped, too. My buddy has owned his shop for 15 years, and he's stumped. Can't figure it out for the life of me. ;/

At this point, I'm hoping that the compressor wheel has oil on it just so I've got an idea where to go next.

I'm not running a restrictor on the turbo (journal bearing) right now, but with it not doing it at every single stop light, and only 1 out of 10 times it's idling for extended periods of time, I don't have much faith in that theory, either.

Just a thought, but what about it being overfilled with oil? Could that cause this, by chance?

I know when I pulled the motor, I modified the water line that runs under the turbo manifold so it was closer to the block, and had to modify my dipstick bracket because of it. I remember telling myself to make sure that the dipstick was pushed all the way down into the block when I modified the bracket / tab holding it onto the car, but I can't 100% guarantee that it is all the way seated. If that's true, the full line could actually be an 1/8" to a 1/4" higher than it should.

When I first put the motor back in, I filled it with 4.5qts, but tt was leaking from the front main after getting it running, so I kept losing a lot of oil and tried to keep it filled based off the dipstick. If the dipstick isn't fully seated, it may have more than 5qts in it, I'm thinking.

My buddy disregarded it being overfilled and causing this issue, so I've almost ruled it out but, at this point, it's the only other thing I can think of.

Anyway, I appreciate the help, though, ya'll. I'll get it figured out somehow. It's at 2,000 miles right now, so when I get to changing the oil again I'll put in 4.5qts and see what happens.

All you sure you have the right dip stick for your block / pan combination ? Not positive but I think there maybe a couple of different dipsticks. The split might be 1.6/1.8 not sure though. How much oil did you put in last oil change ? Also , is the smoke definitely oil smoke ? As apposed to white coolant steam/smoke . Fredb

I bought the car with 170,000 miles on it, so I can't necessarily guarantee it's the right dipstick. I haven't swapped it out myself, just pulled it off to reseal the motor, then put a new o-ring on it and stuck it back in, then had to modify the tab to get it to fit around the modified water line.

When I resealed the motor and put it back in the car, I put in 4.5qts, but the front main was leaking bad once I got it running again, so I kept having to feed it oil until I could fix the front main again. I kept a gallon of oil with me, and would top it back up to the full line on the dipstick each time I would have to go somewhere, or before leaving wherever it was that I went.

It's definitely oil smoke. Thick, blueish/gray, and leaves a nice film on my rear bumper.

At this point , I think I'd pull the turbo . Just to Compare the exhaust manifold vs the turbine outlet and try to figure out if the oil is in fact going through the motor or just being dumped into the exhaust. Either way isn't not doing your cat any favours long term , assuming your running one. Fredb

Right on. That's the next step, probably Tuesday or Wednesday. Followed by another oil change.

I'm running a 2.5" downpipe into 3" straight out the back.

Let us know what you find . Fredb

I guess the general consensus is valve seals. The head gasket, I'm assuming, has 190k on it, so I had planned on replacing it anyways.

Guess the head is coming off next week to do both.

Seals can be done with the head on the motor. It's a little labor intensive but certainly less so than pulling the head. Head gaskets don't wear out, certainly not MLS gaskets like the OEM one. I wouldn't pull the head, personally.

It's the valve seals. There's oil on them when you look in the head. No oil on the compressor side of the turbo. I'm ordering some, and another valve cover gasket to fix the one that never seems to seal for me. ;/

I've watched a ton of videos on the valve seal replacement, and my buddy owns a shop with the tools to do it, so I don't think it's going to be as bad as I made it out to be.

Thanks for the help, ya'll!

Might want to check out the valve guides while your there. If you've pulled the head , throwing a valve grind at it isn't a totally bad idea either. That way you at least know where everything is with the top end. Fredb

Aye lol -- that's my buddy's famous line, too -- "while you're in there."

I had planned on doing it with the head on the car still. If I have to pull the head I'm going to go buy a daily driver (looking at an is300) and pull the motor to put rods and pistons in it, too.

I've spent the last 2 months (and $4,000) going over every inch of the car (sans internals) and am pretty much tired of it at this point, needing a break.

My DIYPNP doesn't want to play well with the automatic transmission / 5 speed swap (I'm assuming, about to make another thread for it), and with the labor involved in changing the seals, I'm still half-tempted to go get another car and let this one sit until I get the motivation back to completely pull the motor again and build it proper.

And that is exactly how I ended up with a 26 year old Miata that I've spent significantly more that the cost of a new ND on.....

lol I'm quickly headed that direction. The IS300 is only $4200 with 116k miles, leather, loaded.

Then there's a 99 bright red Corvette with popup lights I've been eyeing for 2 weeks. I'm afraid to buy the Corvette because I think the Miata will sit. I want to get it finished before I venture into any other roadsters.

This car was super reliable until I boosted it. Then I broke everything. Now I'm almost to the price of the Corvette, and ready to surpass it if I pull the motor again.

I love my Miata, though. At least, I keep telling myself I do.