Exhaust Manifold Gasket oil leak

[Dave_02RX300]

From 2006:  http://us.lexusownersclub.com/forums/topic/33197-failing-exhaust-gasket/#comment-214276

I thought I better post a new thread since the old one is dated 2006, and maybe those lucky folks have new RX's.

About 6 months ago (early 2016) with about 120k on my 2002 RX300, I noticed some burning oil smell, intermittently, at 65+MPH.  I have finally tracked it down to an oil wet spot on two of the bolts that hold the front exhaust manifold.  I'm hoping it's just the gasket, and not a crack in something.

-Dave

[County Boy]

Sounds like an issue I had 2 years ago.  It is difficult to tell where the oil is coming from and certainly I was fooled.  I thought it was coming from lower down but in fact I solved the problem by replacing the front rocker cover gasket.  A very easy job.  Unfortunately, the rear gasket started leaking last year and that is not so easy to replace.  It seems these gaskets have a shelf life and at 330,000kms, mine are reaching that life.  The front gasket went when I was in Mexico and one of their many remarkable mechanics performed a temp solution with silicone.  That cost about $20.  The silicone got me home but the smell of gas returned stronger each day.  Since I had seen the mechanic do the job, and I had bought a new gasket in the states when I was passing thru,  it was an easy fix for me to change the gasket myself.

In conclusion.  Before getting into a difficult and costly job dealing with the manifold, try replacing the cover gasket.

 

Lockie

[Lexus_DK]

Oil leaking at the valve cover gaskets. Make sure you replace the tube seals, the upper intake plenum gasket and the pcv valve while you're at it. You might need 6 new coil connectors too, they are usually brittle and crumble when you're removing them.

[Dave_02RX300]

Thanks for the replies - I have about 125,000 miles on the car.  The issues seems steady state now - now getting worse - I only get the leak+smell when I rev up to 85+mph - California highways ;-).   I'll have a mechanic check it out, especially the valve cover gasket.  I replaced one of those on a 1991 Camry Wagon (V6) a long time ago.

[County Boy]

In my experience, I lost the most oil when I had the reservoir filled.  The dipstick right up as it should be.  This makes sense as there is more oil in the upper chamber, lubricating the valve rockers.  Also, at high revs, there is more oil up top and more likely to leak out under the cover.  I was worried about not doing the repair because I didn't want to drive too many miles knowing that the valves were not getting lubed as they should.  Again, the front bank is a simple correction.  Good luck.

[lenore]

The gasket itself would not cause loss of lubrication unless oil level in the sump gets too low.  The arms and camshaft are lubed thru oil passage ways independent of the cover.  The covers job is to retain the oil that squirts out and return in the passageways back to the sump.

[Dave_02RX300]

The Ody has really been stinkin' for quite a few months.  The oil leak is much worse, and it drips onto the exhaust manifold.  And it shows oil spots on the driveway now.

I'm having the following repaired:  Valve Gasket    Oil pan Gasket   Front main seal

about 800$ of stuff.  Hopefully this will stop all the leaks.  The rear main seal is hopefully OK.  I'll know after this crap is complete.  Otherwise, it's about another 600$.

 

[Dave_02RX300]

It was definitely NOT the Manifold Gasket...  and my last post said Ody (my other car), so the strain has shown...

Repairs complete:

Replace both side Valve Covers (gaskets)
Replace Front Crank Seal and Replace two cam seals
Replace lower oil pan gasket
Change oil and Filter