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Discussion Starter · #1 ·
I have a 06 Lt and when i park and idle for a few minutes then rev it smokes only for a few seconds but lately the clouds are getting bigger. Its white smoke and it smells like burning oil. I've heard head gasket or the rings could need replaced. I will do the work myself but i don't know where to start . Also i have a bluetooth OBD2 reader and it keeps throwing a p0171 code. I have deleted the air intake resonater and i have replaced the muffler with a long style cherry bomber to give her a rumble. Any ideas ??
 

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Are you losing a lot of oil like 1 quart every thousand miles then yes it could be rings or valve blow by


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Discussion Starter · #3 ·
Im adding a quart about every 3 days. I havent thought to keep track of mileage. It does also spit oil or something black out the exhaust when revved sometimes
 

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Valve guide seals are fairly common. Piston rings are the next thing that may cause this issue.

How is the condition of the engine oil? Does it smell of fuel? A product I have used in some of my cars with bad oil consumption called Restore worked wonders. I know it’s really a short term solution. In my case I’d have to change the oil out at least every 3,000 miles because it was thinning out with the fuel mixing in. I suspect the engine was just worn out badly.

My Cobalt does use a bit of oil, not too badly. But I have been using 5W30 Castrol Magnatec, not too expensive at Walmart. I start the oil change with a quart of Lucas original oil stabilizer, not the synthetic. It has helped the rear main seal leak. I no longer leave a spot on the driveway. I do have to add 1/4-1/2 quart every 800-1000 miles. It definitely depends on how I drive the car though. Reving the engine at higher rpms does seem to cause more oil consumption. But that is probably the case with most older engines.

I try to keep the oil change interval no longer than 4,500 miles as the oil seems to become fuel contaminated on my car. Or at least I can smell it on the dipstick. I have noticed this on customer’s vehicles, but a lot worse, and more noticeable. This oil change I am going to change the filter out once or twice just to see how the oil looks at the end of the mileage interval. The filters are cheap, about $3, so I won’t lose much money. In reality I should really try doing an oil analysis. Maybe I will at some point. I have been thinking about replacing the fuel injectors, I’m not sure if maybe they are dripping. The fuel mileage is decent so maybe the car is just suffering from the oil consumption these Ecotec engines are known for. It does worry me about the fuel smell in the oil. But again I smell this with a lot of vehicles when doing the oil changes.

Valve stem seals can be changed on the cylinder head installed on the engine. But you must know what you’re doing and be able to pressurize the cylinder so to keep the valve from dropping into the cylinder. I would rather replace the seals with the head on than have to remove the head. If having to remove the head you might as well do the timing chain and water pump. And really at that point why not just rebuild the engine. Depending on the mileage it might be worth it if the bottom end is pretty worn. Valve stem seals are cheap though.

Anyways, hopefully it is just oil you’re seeing and not coolant smoking from the exhaust. Many times if it’s the head gasket the engine may suffer from overheating. Usually will blow the coolant from the reservoir. Not as common to cause oil to smoke from the exhaust. If the piston rings are really worn badly it will be time to rebuild or find another engine to swap in. A used engine will be cheaper than a rebuild in some cases. At least in labor its way cheaper.
 

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How many miles does the car have? Does the engine also leak oil? I know the oil pressure switch is pretty common to cause oil leaks bad enough to have to keep topping off the oil often. Just had to replace mine. Not saying that’s what’s wrong with yours though.

If it’s really burning a lot of oil, piston rings or valve stem seals are a common culprit.

My friend had bought Chevy Equinox a while back, can’t remember what year it was exactly. It was between 2012-2014. I remember it was shortly after I bought by Cobalt, so about two years agoThe Equinox had the 2.4 Ecotec, and it would burn through 5 quarts of oil within a week or two. She had me look at it thinking a belt was squealing. It was low on oil. Filled it up. She had me look at it again and found that it had used up all the oil I put in there. It was definitely burning it too. It had no leaks, I picked the car up on my lift and had a look. Although this car had under 120,000 miles. It was puzzling to see it use that much oil. But I researched the issues and that was when I found out about the Ecotec engines having oil consumption issues. That was when I started to pay attention to my Cobalt’s oil consumption. While it hasn’t really gotten any worse, it still uses more than it should. I believe the newer Ecotecs like the one in the Equinox have direct injection where as the Cobalts didn’t unless it had the 2.0 turbo. Either way the Ecotec line of engines has had oil consumption issues. Some worse than others.

Now depending on what condition the car is in, it might be worth fixing the engine. It might be better off finding a low mileage engine to swap in. It will likely be the cheapest option. Doing a full rebuild is probably recommended if you want to keep the original engine. If your car needs lots of work, it may be time to look for a new car. I have dumped a lot of money in parts and maintenance into my ‘06 Cobalt. So I would choose to do the repairs if it was on my particular car. I know these cars aren’t worth much though. If you’re going to rebuild the engine you don’t want to cut any corners as it may not last. Things like the timing chain and balance shaft chain sets need to be addressed at the time of a rebuild, I don’t recommend keeping the originals in there when going that far. There are a whole lot of other things that will be easy to change at the same time as well like engine and transmission mounts.

I don’t know if you’ve already done so, but I could recommend starting with doing a compression test so see how bad things are. I have a feeling you may find a cylinder with low compression. Doing a leak down test is also a good place to start as well. That can determine if a cylinder is having problems with piston rings and or valves. It really doesn’t tell you if the valve stem seals are shot though.

Also how often would you change the oil. My car usually is all city driving. Lots of stop and go. Lots of merging onto the freeway, high rpms. I try to change it at 4,000-4,500 miles. Also using synthetic oil.
 

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Discussion Starter · #7 ·
Also noticed it smokes more heavily if ac is on. My cobalt has 220,050 miles. I have just replaced sway bar links ,struts,inner/outer tie rods . car runs strong but smokes bad. I just cant decifer whether its oil or coolant its burning. How difficult is the headgasket to change ??
 
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