2010 LR4 Smoke and codes!
#1
12-31-2022, 05:13 PM
2010 LR4 Smoke and codes!
2010 LR4 95k, was running great, went to move it and smoke started billowing out the tailpipe (oil monitor said oil was pretty much empty) Turned it on again (with oil) and the smoke is less but still going, throwing codes PO316 and a bunch of different cylinder misfire codes. Any ideas on where to start?
Last edited by Hghper; 12-31-2022 at 07:00 PM.
#2
01-01-2023, 04:38 PM
When was the last time the oil level was checked? Just wondering how long it took to run low on oil. Any oil leaking on the ground?
Assuming the smoke is from oil burn (bluish, as opposed to white coolant smoke or dark gasoline smoke), there are only a limited number of ways that I can think of for the oil to get into the combustion chamber: 1) past worn rings; 2) through the valve stem seals, 3) through the crankcase vent system (bad PCV diaphragm), or 4) though the brake vacuum line in the case of a failed vacuum assist pump - this is a strange one, but we’ve had reports on the forums of brake vacuum pumps failing and leaking oil supplied from the crankcase, which then seems to get sucked up the vacuum line and dumped into the air intake causing a lot of smoke.
First thing I’d do is take a look at the vacuum pump. If that’s leaking, fix it - might be your problem right there. The PCV diaphram is pretty easy to check as well and should be changed if it hasn’t been changed in a while even if that’s not your problem. I recommend having the new one in-hand before you pull the old one off as the cap usually gets damaged and can’t be replaced.
Otherwise, if you are getting more smoke on startup, which then seems to go away as the engine runs a couple minutes, that is more likely to be the valve stem seals - oil continues to drip into the chamber when the engine is shut off, then smokes on startup. Although I think valve seals can smoke on decel as well (vacuum sucks oil past seals). I believe worn rings will usually smoke more consistently and can be detected by a compression test.
If the smoke doesn’t have a bluish tint - if it is pure white with a sweet smell or more black - then you probably have a different problem entirely.
Assuming the smoke is from oil burn (bluish, as opposed to white coolant smoke or dark gasoline smoke), there are only a limited number of ways that I can think of for the oil to get into the combustion chamber: 1) past worn rings; 2) through the valve stem seals, 3) through the crankcase vent system (bad PCV diaphragm), or 4) though the brake vacuum line in the case of a failed vacuum assist pump - this is a strange one, but we’ve had reports on the forums of brake vacuum pumps failing and leaking oil supplied from the crankcase, which then seems to get sucked up the vacuum line and dumped into the air intake causing a lot of smoke.
First thing I’d do is take a look at the vacuum pump. If that’s leaking, fix it - might be your problem right there. The PCV diaphram is pretty easy to check as well and should be changed if it hasn’t been changed in a while even if that’s not your problem. I recommend having the new one in-hand before you pull the old one off as the cap usually gets damaged and can’t be replaced.
Otherwise, if you are getting more smoke on startup, which then seems to go away as the engine runs a couple minutes, that is more likely to be the valve stem seals - oil continues to drip into the chamber when the engine is shut off, then smokes on startup. Although I think valve seals can smoke on decel as well (vacuum sucks oil past seals). I believe worn rings will usually smoke more consistently and can be detected by a compression test.
If the smoke doesn’t have a bluish tint - if it is pure white with a sweet smell or more black - then you probably have a different problem entirely.
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