Partywave

UPDATE: not engine sludge issue. Thanks to hypervish for accurately diagnosing my problem as PCV Valve!

I noticed unusual smoke sometimes when I start my RX300 in the morning and after searching the topic on CL I discovered the common issue of engine sludge. Is it possible this situation can improve from frequent synthetic oil changes? Perhaps once per month? Are there other solutions that don't require expensive repair work?

hypervish

Have you checked the PCV valve?

What color is the smoke? It may just be steam. https://www.clublexus.com/forums/mai...s-it-mean.html

If you do think it's sludge, then I suggest pulling the valve covers to verify that.

Partywave

Thanks for the reply, hypervish.

No, I haven't changed the PCV valve. I bought it at 100K miles. It now has 104k. I have the entire service history printed from the Lexus Service Dept and it had every service performed at the dealer through 95K miles. The timing belt was changed at 88K. Do you think the PCV valve would have been included in one of those dealer services?

The color of the smoke seems to be mostly black and even resulted in some excessive black buildup around the lip of the exhaust pipe.

It looks like according to the link you provided black smoke is indicative of a fuel and air issue. I just changed the air filter recently and replaced the 4-yr old battery with a Duralast gel battery. I waited 45 min between disconnecting the old battery and installing the new battery hoping that time span would reset the computer and improve the fuel to air ratio.

But, alas it still smokes when it starts - not every single time, it is more like every other day. Once it is running the smoke doesn't seem to be an issue.

Oh man, removing the valve cover ... that sounds pretty intense. If I remove the valve cover and discover sludge, what should I do. Can it be swabbed out with Q-tips? Would that resolve the problem?

Thanks again,

Dave

code58

Dave,
IF it has sludge, Q-tips aren't going to do you much good. The front valve cover isn't that bad to change, matter of fact pretty easy unless you have no tools or mechanical abilities. I would definitely check the PCV valve to see if it has been changed recently. Next suggestion (IF it has sludge) would be to consider a treatment or 2 with Auto-RX. The trteatment is for 3K mi. and is the only surefire thing to get rid of sludge other than having it all physically torn down and de-sludged. (pretty expensive proposition) Quite true, black smoke is normally too rich a fuel mixture. Oil smoke is normally gray. Oil smoke on start up (gray) is normally from bad valve seals because the oil runs down the valve stem past the seal when sitting and is burned when 1st started, then is clear. Sounds more like sensors are defective and allowing too rich a mixture. Interestingly, my wife's '02 Camry and the '11 Camry also have had excessive black soot around the tail pipe since new but the excellent mileage they have always gotten rules out excessive fuel.

hypervish

Completely agree with Code58. If it does have sludge then Auto-RX is the way to treat it.

I can't be sure that the Dealer would have changed it. Best thing to do is just change it. They are less than $10, and it takes less than 5 minutes to change.

Francis

Dealer did my 90k miles services. But the PCV valve was still original/old so I assumed your dealer might not replaced your too.

Partywave

Thanks guys, I'll take it one step at a time and try replace the PCV valve first. The pics in post #13 and #14 in this DIY thread make it look pretty easy to remove/replace:

https://www.clublexus.com/forums/rx-...out-yours.html

Partywave

UPDATE: Thanks again, guys. Thanks to hypervish for accurately diagnosing my problem as PCV Valve. I was able to locate the PCV using Lexmex's pic below. After I swapped out the PCV for a new one my engine now runs marvelously with no more smoke. You guys are awesome. Thanks again for sharing your expertise.

hypervish

You're welcome.

Glad to hear that it solved the problem!

code58

PW, Hyper had your problem in his crosshairs didn't he???

lexina

Partywave, was your pcv valve plastic or metal?

From what I read most of the plastic pcv valves from the 1st gen rx is a problematic.

hypervish

1999 & 2000 RX have the plastic valve. 2001 and up have metal.

They are not necessarily problematic, but they should be replaced every 30k miles/ 2 years.

Partywave

That's right, guys. My 2000 PCV valve is plastic. The old one was obviously past time for replacement. It felt heavier than the new one (perhaps clogged with gunk inside) and the internal clicker would not click as well as the new one when I shook it back and forth.