A1Lexis

iTrader: (6)

So I brought my 03 UL with 137K in to my Lexus dealer for a synthetic oil change and told my master tech Ive been smelling a faint oil burning smell and suspect the valve cover gaskets were leaking. While the car is on the lift, he noticed a slight oil leak coming from the left gasket onto the manifold.
With the car back on its feet, he tightened all the bolts on bottom of the valve covers to 16lbs of torgue. He did this to both sides. He never touched the top bolts. His reasoning....when he tightened the bottom bolts, it pulls the top bolts tight enough to where theres no reason to touch them. If its going to leak, its going to be at the bottom. After driving 400+ miles on a road trip, I never once smelled the burning oil.
I know this is a temporary fix and sooner or later the covers will need to be removed and new gaskets installed. Heat and age take its toll on gaskets.....they wont last forever.
Thought I would share this great tip for anyone wanting a temporary fix. On another positive note......my air suspension had no leaks!!!! Yay!!

Bocatrip

I too had valve cover leaks both last year on my passenger side (the difficult side to repair) and this year on the driver's side. I too found the valve cover bolts loose and tightened them only to find a month later it was leaking again. Bottom line, there are no shortcuts for our Valve Cover gaskets. They need to be changed around 100k+ as well as the spark plug seals and valve cover screw grommets. Do both sides even if one is leaking. Good luck.

Lavrishevo

iTrader: (1)

I would counter it's an age thing rather than mileage. Many people have well over 100K miles and have no problems with them leaking. Including myself. Although quite common, I would not necessarily have them changed until they start leaking.

ceedub53

I concur, I have 126k on my 02' LS430 and the valve cover gaskets are dry.

MobbinVIP

iTrader: (16)

About a month ago I decided to change mine because I could smell & see oil.
I took my LS to my cousins shop(professional mechanic for over 30yrs)
We started with the passanger side, as soon as he went to loosen the bolts he noticed they all have been loosened up. We removed the valve cover, saw that everything was good. No bad seals, but we replaced all the seals on the passangers side anyways.
Moved to the driver side & noticed again that the top bolts had loosened up. Gaskets were fine. On both sides.

Basically what I am trying to say is...
Before you spend $xxx on replacing the gaskets. Make sure all the bolts are tight first