[Johnny B]

I'm guessing it fuel related. Weak and/or failing fuel pump with low pressure pressure. I'd check the fuel pressure first. Even my cheap OBD2 scanner can monitor live stream fuel pressure.
Also, using some Techron fuel injector cleaner in your gas. Clean your throttle body. And clean the MAF.
This should get you started.

 

[Beaker McChemist]

I'm guessing it fuel related. Weak and/or failing fuel pump with low pressure pressure. I'd check the fuel pressure first. Even my cheap OBD2 scanner can monitor live stream fuel pressure.
Also, using some Techron fuel injector cleaner in your gas. Clean your throttle body. And clean the MAF.
This should get you started.

Thanks. I'll check the MAF. I cleaned the throttle body when I did the valve cover. I just got a OBD reader so I'll look at the fuel pressure.
I can understand how low fuel ratio can cause misfires and hesitation, but how does that cause oil to get in the cylinders/exhaust?

 

[Johnny B]

how does that cause oil to get in the cylinders/exhaust?

Are you now saying this is what is happening? if so that would have been useful information earlier. In fact the normal compression test and oil in cylinders is usually a contradiction.
Anyway, only one other source of oil is past the valve guide seals.

 

[Beaker McChemist]

Are you now saying this is what is happening? if so that would have been useful information earlier. In fact the normal compression test and oil in cylinders is usually a contradiction.
Anyway, only one other source of oil is past the valve guide seals.

Ok. Cylinders wasn't the right thing to say. I'm new at this. The car will hesitate, stutter/misfire, lose power and then huge clouds of smoke will come out the exhaust. It lasts for a minute or so then everything seems to return to normal. Could the oil be getting by the valve seals?

 

[snowwy66]

The car won't run with a weak fuel pump.

Grey oil on acceleration is oil being sucked through the valves.

Smoke on deceleration is oil suckedt the piston rings.

 

[jblackburn]

Do you see lots of oil in the turbo plumbing to the throttle body?

 

[Beaker McChemist]

The car won't run with a weak fuel pump.

Grey oil on acceleration is oil being sucked through the valves.

Smoke on deceleration is oil suckedt the piston rings.

Do you see lots of oil in the turbo plumbing to the throttle body?

My car does not have a turbo. It is probably the most basic model available. 1.8L, L4, DOHC, 16V FFV. No cruise control, no power mirrors. It does have power locks so I have that going for me. lol

 

[Beaker McChemist]

The car won't run with a weak fuel pump.

Grey oil on acceleration is oil being sucked through the valves.

Smoke on deceleration is oil suckedt the piston rings.

Do you see lots of oil in the turbo plumbing to the throttle body?

My car does not have a turbo. It is probably the most basic model available. 1.8L, L4, DOHC, 16V FFV. No cruise control, no power mirrors. It does have power locks so I have that going for me. lol

 

[jblackburn]

My car does not have a turbo. It is probably the most basic model available. 1.8L, L4, DOHC, 16V FFV. No cruise control, no power mirrors. It does have power locks so I have that going for me. lol

Sorry, I missed that in the initial post. Assumed 1.4 when you mentioned the valve cover.

Just to confirm, it's blue smoke you're seeing out the back?

 

[Beaker McChemist]

The car won't run with a weak fuel pump.

Grey oil on acceleration is oil being sucked through the valves.

Smoke on deceleration is oil suckedt the piston rings.

I looked over the car this weekend. The air filter is clean. The MAF is pristine. The throttle body has some carbon buildup but not that bad. I took out the injectors and cleaned them out with cab cleaner. They actuated good and the resistance was 12 ohm. The spray pattern looked good for all of them. The number 2 injector had a lot of oil on the tip and some build up on it. So maybe cylinder 2 is where it is leaking oil?
I looked up replacing valve seals and it looks very complicated. Probably beyond what I feel comfortable with. Not sure how much it will cost to get it done.
I hooked up my OBD reader and the fuel pressure was reading 0.6 psi (4kPa). That seems really low. I don't know if my cheap Bluetooth unit isn't working correctly. Everything else seemed to be in the right ballpark.

 

[Beaker McChemist]

Sorry, I missed that in the initial post. Assumed 1.4 when you mentioned the valve cover.

Just to confirm, it's blue smoke you're seeing out the back?

Thats OK. Yeah. Blueish-grey. Also it smells burnt, not sweet smelling.

 

[snowwy66]

The fuel pump is 60 psi.

About 50 and it starts having problems.
The motor won't usually run below 45.

 

[Beaker McChemist]

I have a 2011 Cruze with a 1.8L non-turbo engine. Every once in a while, usually when I am on the highway going up a long hill, the engine will start to stutter and hesitate. I'll lose power and then it will start billowing smoke. If I pull over and wait, the smoke will go away and then the car will act like normal for a couple of weeks.
I took it to a shop and they did a compression test which came back normal. I changed the spark plugs, coil pack, and valve cover/PCV valve about 5000 miles ago, thinking that would help. It has happened twice since then.
It starts fine and idles normally.
Any ideas what may cause smoke under load?

Follow-up:
Took it back to the mechanic and the piston rings are shot. Not sure whether to get a new engine or sell it as a "mechanic special"

 

[Cruze CTRL]

going up a long hill.. I'll lose power and then.. start billowing smoke.
...I took it to a shop and they did a compression test which came back normal.
Any ideas what may cause smoke under load?

Thank you for the follow up.. (hardly ever happens).
Hope you never use that shop again
What does your new mechanic think was their error doing the comp. test?

 

[Beaker McChemist]

Thank you for the follow up.. (hardly ever happens).
Hope you never use that shop again
What does your new mechanic think was their error doing the comp. test?

No idea about the first compression test. It's not worth them fixing the car.I'll either scrap it or turn it into a project car. I've never done piston work before. If I can't fix it, it's in no worse shape than it is now.

 

[jblackburn]

No idea about the first compression test. It's not worth them fixing the car.I'll either scrap it or turn it into a project car. I've never done piston work before. If I can't fix it, it's in no worse shape than it is now.

Just treat it like a 1990's Corolla. Keep oil in it, and drive the POS til it dies, or sell it to someone for $500 that will.

 

[robertwaynebeam26]

I am 30 yr gm tech I own a 2013 sonic same motor the cruze has problem is water in the fuel the least bit of water under the high pressure fuel system will cause car to miss and smoke white light Grey smoke like it's on fire while going uphill the fuel pump is situated where if u go up hill it will catch the water under the fuel I run a bottle of heat in every take of gas to stop this

 

[Beaker McChemist]

I am 30 yr gm tech I own a 2013 sonic same motor the cruze has problem is water in the fuel the least bit of water under the high pressure fuel system will cause car to miss and smoke white light Grey smoke like it's on fire while going uphill the fuel pump is situated where if u go up hill it will catch the water under the fuel I run a bottle of heat in every take of gas to stop this

Thanks. I still have the car in my driveway. It's been partially disassembled but I am thinking of putting it back together. I finally checked the compression myself and I got 240, 220, 220 and 210 psi for cylinders 1-4. That's not too bad is it? The mechanic told me it had bad piston rings. But I don't know anymore.

Is there a way to drain the gas tank and dry it out?

 

[jblackburn]

Thanks. I still have the car in my driveway. It's been partially disassembled but I am thinking of putting it back together. I finally checked the compression myself and I got 240, 220, 220 and 210 psi for cylinders 1-4. That's not too bad is it? The mechanic told me it had bad piston rings. But I don't know anymore.

Is there a way to drain the gas tank and dry it out?

Those numbers are fine and mostly consistent across the cylinders. You might have a stuck oil control ring or two on the lower cylinders, but there’s lots of ways to attempt to free those up and everyone on the internet has their own method.