I notice this was discussed a few years back. I have a 2004 RX330 with 60000 miles. Had all the services done. Recently, I started using 93 octane gas versus 87 octane gas which is recommended. Since I changed, I noticed a puff of blue smoke only after sitting all-night in the garage. After I drive the rest of the day no smoke after starting. I went to the dealer today and explained this scenario. He stated that since I went to a higher octane gas, the engine burns leaner and hotter upon initial start-up that's why it happens after sitting all night. Unless he is blowing blue smoke up my but , that sounds strange. Any one else experiencing this? if so, what was the problem?

 

In my experience with my older cars, blue smoke on start-up is usually a sign of a very minor oil leak going past the rings. I normally don't consider this to be a problem in my car if: 1. the car has sat for an exteneded period of time. 2. it only happens on the initial start up and doesn't do it after sitting for an hour or so. Fwiw, my 05 330 with 61000 has the slightest hint of blue smoke on start-up, but, like yours, only after sitting all night and not every time.

I can't comment on the premium versus regular comment but it sounds reasonable (that answer and $1 will buy you coffee at McDonalds). Try a test - run your car until almost empty and then fill it with regular for a couple of tanks and see if the problem is still there. I am betting that it will be. My car has only had regular gas in it and it does this only on a very occasional basis.

Since I believe this to be oil, I check my oil more frequently, about once a week.

 

this is indicative of bad valve seals, not bad rings. what happens is when you shut the car off the oil in the head drains back into the block, over time the valve seals wear, and upon draining into the block, some (very little) leaks past the valve seal and gets into the combustion chamber. then on start up, the blue smoke you see is the small amount of oil getting burned out the tail pipe.

if you have powertrain warranty remaining, and if it covers leaky valve seals, i would go back to the dealer and have them replaced.

this will surely reduce resale, as the next prospective buyer will see the blue smoke as well.

it will not hurt anything by not getting it fixed. perhaps keep an eye on the oil level, but i wouldnt suspect you would see it go down very much.

this repair can be done without taking the heads off the engine, but you will still be looking at alot of labour( timing belt would have to come off, as well as the cams)

 

when you are going up a hill, stomp on the acclerator and look for smoke. A cloud behind you means engine rebuild time.

Some smoke during start up, when the parts are not at temperature yet, is a minor thing.

 

mine does the same thing, 2004 106,000. Mine isnt a little though, its a small cloud. oh well. haha

 

Kiwi's post hit it right on the head.

 

Hello, my RX300 (2000 with 180K) sometimes blows blue smoke BUT not every start. Some times I leave it overnight and it blows a big cloud of smoke and then it goes away after a minute, other mornings there is no blue smoke at all. Also, I noticed that after driving at high speed it burns some oil, but city driving not so much. I took the valve covers off (rear one was a PITA), I cleaned out the valve cover PCV cavity with carb cleaner (on both covers) and it did not seem plugged at all. I also have a check engine light that stays on for most of the time but sometimes goes off, the code is P0440, could this code cause the intermittent blue smoke. My guess is that the valve seals are starting to go and depending on what position the valve is in when the engine stops it either leaks a little or not.

All help is appreciated

Thanks

 

0440 is usually a evap fauly code. unrelated to oil issues