By October 21, 2006 1 Comments Read More →

Lexus Smokes Out Tailpipe

I drive a Lexus RX 300 and recently had a oil light come on and took it in for an oil change only to discover the jerks did not change the oil and filter.

I took it and had the oil changed FOR REAL but now I’m getting blue smoke on startup.

Any idea on what is causing the blue smoke? I’d like to know more when I take it lexus service . The Car runs like a pearl and no oil light since it was changed for real.

Thx in advance for your response

Hello there, thanks for the email

Well that is a hard question to answer. If you have blue exhaust smoke, it is most likely caused from the engine burning engine oil which it should not do. I am assuming since the mechanic did NOT change the oil and filter like you though he did, the oil change was/is severely past due, and probably very low on oil hence the oil light came on.

So what I am assuming happened is this.

The engine ran dangerously low on engine oil (once the red warning light finally comes on, it s dangerously low) and you probably continued to drive the vehicle some while the light was coming on, coupled with the fact that what little engine oil was in the engine it was VERY old and dirty since the oil change was missed by the mechanic. Am I correct?

What can you do now? Is there warranty still in effect from Lexus? Are you going to take it to Lexus and try to get them to repair it under a warranty claim? I would first ask your local repair shop to check the engine oil dipstick, and look under the oil filler cap for signs of oil sludge, which is a symptom of lack of oil changes. Sludge = dirty old worn out engine oil that is now in a solid form like mud, usually gritty feeling and black in color.

You can usually tell if an engine has been well maintained and the oil change intervals have been kept up to date. If sludge is on the oil filler cap, (stick your finger inside the oil filler hole and run it around the tops of the valve cover and inside to see how much sludge you can get on your finger) If you get sludge on your finger, the bottom of the motor is really going to be full of it.

I say this because if you take this vehicle to the dealer claiming a warranty you might want to cover your bases first and make sure the obvious signs are not visible to the dealer .who will certainly look into this.

If what I say above it true, you probably have done some internal damage to the engine or at least to the valve train located in the top of the cylinder head. The valve stem seals inside the cylinder head can crack and seep oil into the cylinder overnight, causing smoke on start up. This could be a costly repair, and some tests should be done before you tear into anything this is a complex engine.

You might want to try using thicker weight engine oils and see if that helps reduce the smoke. Maybe a straight 30 or 40 weight oil? You should talk to your mechanic and get their opinion, oil weights can make a difference depending on the climate you are located in. There are many over the counter oil additives that might also help reduce the smoke. Brand name – ATP AT-205 is one oil additive I have used in the past with success. You can find at your local auto parts store.

Again, talk to your local mechanic before you use any additives, especially if this engine is still under factory warranty.


Austin C. Davis

Reader Follow Up

Austin, thanks for your detailed reply, you are right on the money!

About the Author:

Austin Davis, consumer car repair advocate. "Hi there! I love to help people solve their car repair problems and I hope my site was helpful to you today. Thank you for stopping by."
  • bmw

    Should’ve bought a BMW :)