Why would a 99 Lexus RX be smoking blue on and off when I first start it?
What is your question?
Bought this 1 owner w/130k 900 miles ago. No smoke in 78 degree weather. Check engine light on 3 days after purchase, dealer cleaned o2 sensor, apt. for new one. Then 1st notice a little blue smoke at cold startup cooler o.s. temp (45), sometimes a lot, not always. All cold starts. Used 3/4 of a quart in 7-800 miles.
Since then dealer free changed from oil partial syn to straight. Please no discussion about that experiment unless relevant.
2 engine starts since oil change, 1st little smoke, day 2 sustained cloud equal to previous worst. See what happens tomorrow.
Spoke to previous owner before I bought he told me he changed it with regular oil at home (but admitted that he let it go to 4000+ ,some bs about a little leak, cardboard on garage floor? No evidence of a leak ever seen).
Blank carfax for oil changes, assuming dealer serviced under factory warranty.
Very good once over at 86k.
Valve stem seals, sludge or what, weather temperature being the same on cold starts?
Thanks
What makes this problem better or worse?
Unknown
How long has your 1999 Lexus RX300 had this problem?
RepairPal Certified shops can diagnose and repair your 1999 Lexus RX300. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
Start with the cheapest and easiest route. The pcv valve. Its about a $5 part located on the passenger valve cover. It should have been replaced by now but you never know.
Alex
Blue (oil) smoke upon 'cold' start is indicative of failing valve stem seals .. It is possible there is some upper engine sludge that's interfering with 'oil drain back' resulting in oil ponding under valve cover - which would be a contributing factor .. Hands-on inspection will be necessary.
For some interesting reading about this *common problem* with the 3.0L engine - copy and paste the link below:
https://www.justanswer.com/lexus/4tjbb-lexus-rx-300-hello-my-1999-lexus-rx-300-suddenly-developed.html
Good luck with it!
Today's cold start was a no smoke event . Bought it with the free 90 day/3000 mi. ASC warranty. Stopped at dealer pay balance on 02 sensor replacement, had a chat about all of the above and valve covers front easy, back not so much. Valve stem seals you practically have to pull the motor to get at. Forgot to mention pcv, which might have been a good thing, I'll find it myself. Got to crawl underneath to check out 02 sensor work done too.
Thanks again for your thoughts on this.
Thanks, I'll take a look at it. Somewhere else a suggestion more work to pull the valve cover and make sure drains are clean?