2016 Kia Sorento LX 2.4l I4
Bought this car with 92k miles. Saw that it was burning/consuming oil. Researched, but after reading everywhere online, saw that this was about normal for a Kia, so I just kept adding. I think about 1 quart every 1000 miles, but I never measured accurately. I did notice the spark plugs were getting nasty.
At 109k, it burnt a valve. Replaced the burnt valve. Since 99% of online posts say the piston rings cause the oil consumption in these engines, I did a bottom end rebuild (piston rings/rod bearings/etc). When I got back on the road, I measured the oil consumption, again was burning 1 qt about every 600-700 miles (no change at all!)
At 118k, another burnt valve. At this point, I thought: oil can only get into the cylinder from piston rings, valve seals, or the pcv. I thought, maybe I have bad valve seals, even though I don't have smoke. Pulled the head and did a top end rebuild (all new valves, seals, etc).
Before driving it, I thought that I would install an oil catch can to monitor any oil there. Previously I had read about oil catch cans, but had also seen many against it, saying that it was not necessary, maybe voided warranties, etc. At this point, their opinions did not matter anymore. I saw enough oil inside the intake to justify it. I bought a cheap $30 OCC online, and installed it between the pcv valve and intake.
Started driving, immediately saw that I had caught 1/2 qt of oil with the OCC in only 300 miles! I replaced the PCV valve, no difference. The valve itself is not the problem.
Removed the hose between the OCC and the intake, replaced with a simple breather. Driven about 400 miles, no oil getting in the OCC! Oil level in the crankcase is stable! The oil still looks and smells good! It seems that the issue is solved. Unfortunately I don't get paid for this research (but I hope that it helps someone)
Questions to consider:
1) The oil consumption issue seems to be very common in these cars. Is it possible, that most ALL cases of oil consumption is from a bad pcv system? I think it is easy for all forum members to respond with "the piston rings are wore", but how many rebuilds prove this? I cannot find 1 post/thread out there, where the piston rings were replaced and the oil consumption disappeared. And I figure Kia would not advise anyone to vent the pcv, that would basically be illegal since its emissions related. And if the pcv system cannot be fixed/redesigned, is this why they avoid dealing with it? It is ridiculous to read that 1 qt consumed in 1000 miles is acceptable to Kia. This sounds like their 'escape' from the issue.
2) What causes the PCV system to dump oil? A car with low miles seems to not have the issue, and one with higher miles seems to develop it. It is not the PCV valve, I replaced it 3 times with OEM, and no difference. The valve cover was cleaned/inspected, but the inside of the baffle is not really accessible. Oil does splatter inside the crankcase, and could be altered with wear etc. There is a 'intake oil control valve filter screen' in the block that I found AFTER the 2nd build, so I did not get to inspect it (why would they put a filter in the block!). But, it is not spewing oil with the breather. I would say for some reason, the intake is 'sucking' too hard, since no oil is being 'pushed' out the breather. How/why is the intake sucking too hard? I replaced air filter and cleaned throttle body on the intake side. Vacuum would be higher in the intake when the throttle body is closed, but the OCC was also filling up with oil while driving on the interstate.
Below is image of the OCC installed between the pcv valve and the intake (note: the pcv valve has not yet been drilled out)
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Below is images of the OCC installed between on pcv valve and vented (note: the pcv valve has been drilled out, and the breather hose on the rear of the valve cover is also removed)
![Image]()
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Bought this car with 92k miles. Saw that it was burning/consuming oil. Researched, but after reading everywhere online, saw that this was about normal for a Kia, so I just kept adding. I think about 1 quart every 1000 miles, but I never measured accurately. I did notice the spark plugs were getting nasty.
At 109k, it burnt a valve. Replaced the burnt valve. Since 99% of online posts say the piston rings cause the oil consumption in these engines, I did a bottom end rebuild (piston rings/rod bearings/etc). When I got back on the road, I measured the oil consumption, again was burning 1 qt about every 600-700 miles (no change at all!)
At 118k, another burnt valve. At this point, I thought: oil can only get into the cylinder from piston rings, valve seals, or the pcv. I thought, maybe I have bad valve seals, even though I don't have smoke. Pulled the head and did a top end rebuild (all new valves, seals, etc).
Before driving it, I thought that I would install an oil catch can to monitor any oil there. Previously I had read about oil catch cans, but had also seen many against it, saying that it was not necessary, maybe voided warranties, etc. At this point, their opinions did not matter anymore. I saw enough oil inside the intake to justify it. I bought a cheap $30 OCC online, and installed it between the pcv valve and intake.
Started driving, immediately saw that I had caught 1/2 qt of oil with the OCC in only 300 miles! I replaced the PCV valve, no difference. The valve itself is not the problem.
Removed the hose between the OCC and the intake, replaced with a simple breather. Driven about 400 miles, no oil getting in the OCC! Oil level in the crankcase is stable! The oil still looks and smells good! It seems that the issue is solved. Unfortunately I don't get paid for this research (but I hope that it helps someone)
Questions to consider:
1) The oil consumption issue seems to be very common in these cars. Is it possible, that most ALL cases of oil consumption is from a bad pcv system? I think it is easy for all forum members to respond with "the piston rings are wore", but how many rebuilds prove this? I cannot find 1 post/thread out there, where the piston rings were replaced and the oil consumption disappeared. And I figure Kia would not advise anyone to vent the pcv, that would basically be illegal since its emissions related. And if the pcv system cannot be fixed/redesigned, is this why they avoid dealing with it? It is ridiculous to read that 1 qt consumed in 1000 miles is acceptable to Kia. This sounds like their 'escape' from the issue.
2) What causes the PCV system to dump oil? A car with low miles seems to not have the issue, and one with higher miles seems to develop it. It is not the PCV valve, I replaced it 3 times with OEM, and no difference. The valve cover was cleaned/inspected, but the inside of the baffle is not really accessible. Oil does splatter inside the crankcase, and could be altered with wear etc. There is a 'intake oil control valve filter screen' in the block that I found AFTER the 2nd build, so I did not get to inspect it (why would they put a filter in the block!). But, it is not spewing oil with the breather. I would say for some reason, the intake is 'sucking' too hard, since no oil is being 'pushed' out the breather. How/why is the intake sucking too hard? I replaced air filter and cleaned throttle body on the intake side. Vacuum would be higher in the intake when the throttle body is closed, but the OCC was also filling up with oil while driving on the interstate.
Below is image of the OCC installed between the pcv valve and the intake (note: the pcv valve has not yet been drilled out)
Below is images of the OCC installed between on pcv valve and vented (note: the pcv valve has been drilled out, and the breather hose on the rear of the valve cover is also removed)
