Oil burning on startup

[Gordo2001]

One of our cars is a 1992 lexus SC400 (4.0 V8)with 180K miles that sometimes puts out a puff of smoke on startup. The longer it sits the worse it is. If it is run daily it is not even noticeable, and oil consumption is negligible. I am assuming the oil is leaking past the valve seals.
Would changing the oil weight from the recommended 5W-30 help? Do I need the XXW higher or the w-XX higher or both?ie would you recommend going to a 10W-30, a 5W-40 or a10W-40. Or do you think I should just stick with the 5W-30?
Thanks.

 

[JohnBrowning]

Do yourself and your car a favor. Order two bottles of Auto-Rx and have fun. It will gently clean all the deposits out of the engine and allow the filter to catch them all.It will clean the seals and revitilize them without damageing them. If the seals are physicaly damaged then nothing will help but Auto-Rx has a good track record. I would do at least one clean and rinse phase with auto-Rx then repeat. After that I would consider a 10W40 or 15W40.

 

[Gordo2001]

Thanks for the advise. I must admit I had not considered Auto RX. I need to do a search to find out more about it...

 

[ericthepig]

I haven't tried the Auto-RX, but perhaps I should. But meanwhile (for me) HM oils have brought my smoke at start-up to un-noticeable levels (every once in a while I'll see a little whiff).

 

[ericthepig]

HM oils that I have used that work -

Valv. MaxLife
Castrol HM
SuperTech HM

And, no, the heavier wgt oil will likely not help you (I tried 20w50 - didn't help my smoke situation).

 

[Merkava_4]

All you need is Maxlife 10W-30. It will weld the valve seals back together.

Seriously, that's what they say on their TV commercial.

 

[Gordo2001]

Wow, that's what I need, a little magic!