In have a 2005 Toyota Camry with 120,000 miles. Upon starting the engine there is a puff of blue smoke with smell of oil burning. There does not appear to be any smoke during the running of the car. Any clues on what the root cause could be? Rings? Head gasket?
Most likely the seals on your valve guides are worn out.
In your situation, most people would just ignore the problem and closely monitor the oil level, and I suggest that you do the same.
The same thing happened to my '96. Which engine do you have? I lived with it, I checked the oil levels, didn’t seem to affect oil consumption.
@VDCdriver is correct. It’s more likely valve guides. When they are worn…over time they’ll drip oil into the combustion chamber. Then when you start the engine…the oil is burned off (which you see as blue smoke). This is not really anything that needs immediate attention. My 90 pathinder was doing this when it reached about 250k miles. I never fixed it and sold it when it had over 300k miles. Between oil changes I’d be down about a pint. Engine had no other problems.
Another possibility other than valve seals or guides could be oil sludge in the valve train area. This can plug up oil return holes and cause oil pooling in that area. With the engine off oil oozes past the seals and guides and ergo, smoke upon startup.
It could also be that oil consumption is continuing even if you don’t notice it. After the initial cloud which is the oil that has oozed into the valve ports the problem may still be there; just not as noticeable.
The valve cover could be pulled and the valve train area inspected for oil sludging or coking. Valve seals could be replaced if desired without too much engine disassembly.
Worn and leaky valve guides most likely. I’ve had two cars with this problem. One way to check is to go about 50 mph and take your foot off the gas. The engine vacuum will suck the oil past the guides, showing blue smoke.
Before catalytic converters this test was easier.
Valve seals are worn out. Simple to fix and can be done on the car without removing the head if you want to go the cheap route. If not pull the heads and have a machine shop do them.
Steve
It’s not easy to replace the valve guide seals on this engine.
You have to remove the camshafts and then remove the lifters and shims. And you can’t mix up where the lifters and shims are located.
If the oil burning at start-up bothers you, start using a high mileage oil such as Valvoline Max-Life. These high mileage oils have additives the cause the seals to swell slightly preventing oil from leaking past the seals.
Tester
As long as your oil consumption is reasonable, a quart every 1000 miles or so, you can safely ignore this issue. “Fixing” it (new stem seals) can result in worse problems…
Thanks to everyone who responded. I feel better about the problem and will likely accept the suggestion to monitor the oil level, use a high mileage oil, and just ride it out. Good luck to all.
What engine?
4 cylinder or V6 . . . ?
FYI OP, when there’s a problem with the valve guides or their seals, that’s the symptom. Oil isn’t supposed to be able to enter the cylinder from the top of the engine through the valve stems. But the valve stems have to be able to move up and down, so there’s a dynamic seal there, and it can fail over time. When it fails, after you turn off the engine oil in the top area will leak down into the cylinders, and next time you start the engine the next time that oil will create a brief puff of blue smoke on startup.
While this can cause problems over time, such as fouling the spark plugs, or damaging the cat, as long as the oil consumption is within Toyota’s spec, me, I’d live w/it.
It is a 4 cylinder.
I had a VW Rabbit that had bad valve stem seals. Replacing them fixed this symptom. On some engines it is pretty easy to replace the valve stem seals. Others, not so much. If you have the easy kind, what they do is pump compressed air into the cylinder through the spark plug hole. That creates enough force to prevent the valve from dropping into the cylinder (due to gravity) while the keeper is removed so the seal can be replaced.
4 cylinder valve seals are a walk in the park for a tech that has worked on theese enginges before. The v6 is not bad if you have the correct tools, either one can he done in a day. If it was mine I would drive it and check the oil on a regular basis.
Steve
I’m kind of surprised that the valve stem seals are already shot
This is no 20 year old car with 250K
The only reason I could think of for valve seals being gone (if that is the cause) would be if the engine has suffered some chronic or severe overheating.
Maybe a look inside that valve cover is in order to weed out oil coking and pooling.
I’m reminded of the dealer I worked for who bought about 3 dozen Chevrolet fleet cars. Every one of them had between 30 and 40k miles and had been used mostly for city driving by company reps and with very few oil changes being performed on them.
Every single one of those cars smoked on startup.
Every single one of those cars had coked up valve trains and clogged oil return passages.
When a mechanic was in between jobs or held up on parts they would grab one off the back lot and start in with the PITA job of cleaning the valve train up and opening up the drain holes.