OIL LEAK of head cylinder gasket: could this ...

[odie]

cause it ? Is it possible that the extreme heat of the exhaust manifold to cause the multi layered steel head cylinder gasket of the #1 cylinder to leak oil externally since it's so close to the manifold ? Here's a video of the location of the oil leak , www.youtube.com/watch?v=EVK_uBKotcU . When you PAUSE the video at 18 seconds you'll notice how close the black thin cylinder gasket is to the exhaust manifold . Was reading at WIKIPEDIA how aluminum blocks are more prone to leaks due to aluminum heads expanding / contracting than that of cast iron heads . Here's the article , http://wikipedia.org/wiki/Head_gasket found under GASKET PROBLEMS . Therefore the high heat of the manifold would impact the seal of the gasket between the head and lower block .

 

[willix]

I have heard of this. I would think it would be more of a oil presence or very minor seepage rather than calling it a leak.

Flat sealing surfaces become more critical to achieve a proper seal.

 

[odie]

" I would think it would be more of a oil presence or very minor seepage rather than calling it a leak. "

The oil that seeps / leaks reaches all the way to the oil pan . The one car we own with the leak had the head cylinder gasket replaced under warranty and the leak has stopped . The newer M.L.S. gasket seems thicker than the head cylinder gasket installed at the factory . We have another car that has same leak and a friend as well . These are all the same models . One is an 2008 and the others are 2010s .

 

[willix]

An identity of the make & model would be more helpful at this point.

It really is helpful to know the application from the start.

 

[punisher]

MLS gaskets tend to leak more than other styles. They are picky as [censored] about surface finish. I know this, sadly.

No quick fix I know of. The oil can wick between layers (especially near any pressurized oil passage(s) to the head), or at corners near drainbacks. Any surface roughness on head/block, or imperfections, are an invitation for leaks.

If you want to use MLS gaskets, and reduce leak problems, resurface head and block to the required finish. You can also go back with a composite gasket if offered for that application.

Wouldn't hurt to check around and see if any company (Cometic/Fel-Pro) offers new type MLS that work better on rougher surfaces. Maybe there is some surface prep spray/sealer that can be applied to the gasket surface before assembly to alleviate some problems.

I ran copper head gaskets, leaked water. Ran MLS gaskets, leaked oil. Can't win.

 

[goodtimes]

Do you have the two nearly new Yarises, both with bad head gaskets? Or was that some other guy? The Yarises have all aluminum engines, no mismatched expansion going on. There is nothing wrong with the exhaust etc either, Al is a good conductor, and the engine is water cooled. Every engine I can think of has the exhaust manifold bolted to the head. The hot exhaust is expelled through the head itself.

 

[odie]

Yes , the two YARIS ( '08 + '10 ) we own and a friends 2010 that has the same oil leak / seapage .

 

[odie]

" The Yarises have all aluminum engines, no mismatched expansion going on. "

How can you be so sure of that ?

" There is nothing wrong with the exhaust etc either "

How can you be so sure of that as well ?

" the engine is water cooled. "

Quite aware of that .

So what's your take on why all these cars have the same oil leak / seepage ? Defective batch of head cylinder gaskets ? The '08 has stopped leaking / seeping oil after being replaced under warranty . Thus the original M.L.S. gasket was likely defective .TOYOTA does not share their findings with the consumer / public . We were told this by the technician that overlooked the work performed on the '08 and by the TOYOTA customer relations rep that handled our case . So we'll never know what was / wasn't discovered to be wrong with the original gasket

. What else can cause the head cylinder gasket to seep / leak oil from these new / low mileage engines ?

 

[goodtimes]

You can read the engines are aluminum on a website describing the engine, you can use a magnet, you can see it is silver not black, or you can take a knife and scratch it, and prove it to yourself.

I don't really have the energy for the rest of it, I am sure you are right about everything. Just remember they replace other things when doing a head, that are the more usual sources of oil leaks.