Burning Oil On Startup

[hulahoopian]

Is there a known problem with oil getting into the cylinders when the car is left for a few days ? My 2001 RAV4 2.0 petrol issues a cloud of smoke when I start it after leaving it for a few days. It doesn't really seem to use any oil otherwise (haven't needed to top it up at all since it had an oil change in Oct 11, but I only use it at weekends and have only done about 4k miles). I'm assuming that oil is getting past the valve stem seals, but who knows ?

[Davrav]

What colour is the smoke [and no I don't mean emanating from the Vatican :) ]

[anchorman]

Yes, past the valve seals and in through the odd open valves. What is caught by closed valves gets in when you start it. I wouldn't worry.

[Big Kev]

Condensation from sitting unused.......?

[flyboyprowler]

My old mini cooper "S", and a lot of performance cars had this problem. As you suggest, oil passing by the valve seals. A compression test would show any major problems with the head, As we get older, as with our cars, stuff leaks out of various orifices, LOL, and what mileage has your car done, it may be feeling its age!

[hulahoopian]

I'm 100% sure it's engine oil, big cloud of blue smoke and it stinks like burning oil, but only after it's being sitting a while. I'm not worried about it because it doesn't really amount to much usage (it must be self-limiting in how much I can lose in one go), I just wondered if it was a known problem. I don't think I've got any compression issues and it doesn't seem to use any oil apart from this. It's done 84k miles now, which doesn't seem a lot by modern standards (I've have plenty of cars with more miles than this and this is the first one that's ever done it). I've vaguely considered having the head off but it doesn't seem worth the effort. I'm aware of some Toyota engines burning oil in everyday usage, but I haven't heard of this before.

[Tech01]

As Anchorman says, if this smoke only occurs at start-up (and after a lay up), I shouldn't worry too much.

A quick method of checking compression - i.e. to check that you haven't got one cylinder or two cylinders with low compression - is as follows:

- With a warmed up engine...

- Temporarily disconnect all the HT plus leads (or otherwise stop the plugs from firing)

- Crank the engine on the starter, for several seconds, and LISTEN

- You should hear each cylinder compressing in turn, and they should all sound the same.

- If one/more cylinders is down on compression, the cranking with momentarily accelerate, and then slow again (i.e. uneven cranking)

If you get this unevenness, move on to a check with a compression tester.

If two neighbouring cylinders show up low on the gauge, suspect the head gasket.

Chris