I’ve been checking out used Suburus and it seems that the ones I’ve looked at (2002 and '02) had a lot of corrosion on the battery posts. So much so that the tie-down strapped was affected. Why do these cars have the corrosion problem? I’ve never had a prob like this on any other vehicle I’ve owned. I also have heard that the corrosion is a partial cause of the head gasket failure. Any truth? Thanks

I meant tie-down strap…

I might be wrong, but I think that the most common cause of corrosion around the battery posts is failure of the seals at the battery posts. Maybe the OE batteries in Subarus are weak there. The other cause of leaks at the posts, in addtion to aged and possible poor design, is careless installation. I have seen ham-fisted parts-store chimps twist the posts in way they should not while installing them.

“I also have heard that the corrosion is a partial cause of the head gasket failure.”

That is certainly a “unique” theory.

While 2.5 liter Subarus of the '96-'02 vintage definitely have head gasket issues, the theory that battery corrosion has something to do with head gasket failure is…I will try to be kind…extremely naive and ill-informed.

I can’t explain why you observed this pattern of battery corrosion on both “2002 and '02” Subarus, but it could simply be the result of poor maintenance. Or it could relate to poor quality of the original batteries. However, if you are looking at 7 year old cars of any make, and if those cars have the original battery, you have to be aware that those batteries are ready–or overdue–for replacement.

I would love to learn about the mechanical/automotive qualifications of the people who came up with this theory of battery corrosion being the cause of head gasket failure.

I ran across the following link once, I visited this shop once driving on a x-country shop and having a repair performed here while visiting relative:

That’s the site where I heard about the corrosion theory.

I think the battery corrosion is due to poor maintenance and is not specific to Subaru vehicles. I think whoever installed the batteries in the cars you looked The (2002 and the '02) at may be responsible. The terminals on my Subaru’s battery don’t have a “corrosion problem” and I don’t do anything special to them.

I don’t see how battery corrosion can have anything to do with head gaskets, Subaru or otherwise. Is this a joke?

And, yes, I tried the link to the “explanation.” Several times, in fact. It has yet to work for me, so I can’t read this amazing theory. I’ll keep trying, but I don’t expect to be convinced.

Perhaps it would help if you told us why you were looking at Subarus.

Try this link:
I"m looking for a “new” car. It’s between a RAV4 and a Subie Outback. I just don’t want to buy someone else’s headache.

Ok, I typed in a different link to that site, but when i hit “submit” it came up as the other one. Sorry

Now that I’ve read it I remember seeing this before. I still think it’s a heck of a stretch, and even the website says battery corrosion is not the main reason for head gasket failure.

Anyone who allows their battery terminals to get that bad is not doing proper maintenance and is probably not doing ANY preventive maintenance. These would be used cars to avoid.

I agree with mcparadise on both counts–that the battery/head gasket theory is just a bit far-fetched and that one should not be interested in buying such a poorly maintained car.

Whether one is looking at Subarus, Buicks, Toyotas, or Bentleys, a car with lots of battery corrosion is one that has not been maintained properly. If highly visible things like mounds of corrosion on battery terminals and the tiedown have been ignored, just imagine how little attention has been paid to things like transmission fluid changes, coolant flushes, and brake fluid changes.

Avoid any used car that has such tangible signs of lack of maintenance.

Thanks for the input, everyone. It just seemed odd that I looked at 2 Subbies in an hour and BOTH had substantial signs of corrosion. The one at the dealership was, of course cleaned up, but the tie down strap had all the paint eaten off. What are the odds of 2 cars having the same condition? Hmmmm Coincidence?

Coincidence? Probably not, since we hear daily on this site about used cars that had little or no maintenance from their first owner. Poor maintenance is actually rather common, apparently.

If I were purchasing a Subaru Legacy/Outback, jump to the 2005+ range. The engine has no real reports of head gasket problems(changed that year) and is a far superior car than the previous ones especially the interior.