200k miles on es300 that smokes on start up... I suspect it's due to a bad valve seal...I run 5w-30...will using 10w- or 15w 30...minimize oil consumption/reducing smoke on start up? I live in a region where winters are cold.

 

It's bc oil leak from a seal. When engine gets warm it burns the oil, thus causing smoke.
Happened to my 96 ES

 

Welcome to CL.

On the start-up, are you sure it's actual blue/white smoke from oil-consumption and not just simple steam from moisture building up in the exhaust-pipe while sitting overnight? Some white steam moisture/vapor clouds are normal on a cold start and warm-up, until all the moisture evaporates out of the system from the heat.

If it continues to smoke while fully warm, of course, then, yes, that's one sign of excessive wear inside the engine...bearings, valves, rings, etc..... And the smoke can be verified by an emissions test.

 

Positive...

 

Smoke on startup is very likely valve stem seals. If these seals are bad the engine will use oil but usually nothing excessive.

 

[QUOTE=Lexus2000;9442378]Smoke on startup is very likely valve stem seals. If these seals are bad the engine will use oil but usually nothing excessive.[/QUOT

Maybe Im not asking the the correct question the correct way....will using a heavier weight oil reduce usage and will it harm anything?

 

High-mileage oil is often recommended for old engines like yours, with loose tolerances. It has a slightly different viscosity and special additives in it that will lessen oil-consumption. Here's an example from Peak, but it is available in a number of different brands, both petroleum-based and synthetic.

 

Worn valve stem seals are not a tolerance issue the rings are very likely perfectly fine. Put another way replacing the seals will make oil consumption drop down to almost nothing. Thicker oil will help but don't go crazy and use something like 20W-50 I'd say 10W-40 is the upper end of what you should use in the summer.

 

At 200K miles? Perhaps so, but I couldn't bet on it.

 

I've done it myself on two engines that were over 200k miles (one was over 300) the smoking on startup was obviously gone but the oil burning dropped to less than 1 liter over a 5000 mile oil change. There is a member over at TN who replaced the HGs and seals on a 3VZ-FE the engine was at about 320,000 miles his oil burning dropped drastically. Sadly the car ended up getting totaled.

Other accounts of people doing this had similar results. A tear down of a 200k+ Toyota V6 shows the crosshatch pattern still on the cylinder walls. The valve stem seals are a weakness for sure they dry out and basically disintegrate when removing.

 

Thanks to all who replied...think I'll give the 10w-a try as the weather warms up...is 10w-30 ok to use? Interesting how the amount of smoke differs from time to time...