Theorectical 2.5 head gasket question?

[1997reduxe]

I have a question regarding 2.5 head gaskets.

Would there be any evidence to suggest that the historical problems encountered by so many regarding the 2.5s could have had to do with not only the design issues but also that the engines in question were in regions of highly fluctuating temperatures, such as places where it gets really cold and the engines were submitted to freezing overnight and then the sudden heating upon starting?

I was just wondering. I recently bought a 2.5 99 Outback, and it has almost 140k and absolutely is stable as a rock, but again it is and has always been a TX car, so not subject to cold temps of up north.

And also, whether having the engine warming device installed ever was good in dealing with same gasket issues?

Just wondering?

Thanks a lot.

'97

[forester2002s]

This is an interesting idea.

However I'm not sure that the coldness of the engine-block at start-up would make much of a difference.

Let's assume that an engine-block at operating temperatrure is at about 150 degC (I'm guessing, I'm open to being corrected).

In a warm-temperature environment (say 20 degC ambient), the temperature difference from cold-start to operating temperature would be 150 minus 20 = 130 degC.

In a colder climate (say minus 10 degC ambient), the temperature difference would be 150 minus -10 = 160 degC.

So would these two temperature differentials (130 vs. 160 degC) make that much difference to the behaviour of the engine-block and head-gaskets?

I somehow doubt it.

We need someone with experience in engine design to comment....

[idosubaru]

No.  zero and 100 degrees are both cold to an ICE.

 

Can you find original HG subaru's in Texas? yes of course you can.  can you find original headgasket Subarus in Canada - yes as well.

 

. I recently bought a 2.5 99 Outback, and it has almost 140k and absolutely is stable as a rock, but again it is and has always been a TX car, so not subject to cold temps of up north.7

 

Many people who "recently bought" a car don't have issues with it - that is the norm, not the exception.

1. not many miles on it - so you have almost zero experience so far

2. do you even know if the headgaskets are 100% verifiable original?  many have already been replaced many moons ago - i've bought some that had the HG's replaced at 30,000 miles under warranty - these things were blowing well over a decade ago.

[Ibreakstuff]

The ej25 HG issue is probably more directly related to the inferior first gen MLS gaskets. But obviously the surface RA, flatness, and the open deck sleeves vibrating can confound the issue.

The engine peaks around 210F, maybe a little bit higher with heat soak when you turn the motor off. Ambient temps effect this but not as much as you would think.