Is this a good deal or a bad one?
 

I have found a 2004 Mazda 3 hatchback for sale for only $3200. It has 139,000 miles amd it has a manual transmission. Seller is a dealer and doesn't know whether the clutch has been replaced. How long can a clutch last on this car? How can I tell whether its been replaced or at least test the condition of the clutch? Otherwise, it looks to be in good condition with leather seats and good paint.

Hmmm, if it has leather seats, then I'm guessing it is a Mazda3 s Grand Touring (or something like that) and has the 2.3 liter motor. Here in the U.S. the 2.3 has a very spotty reputation for reliability in that the internal oil control was not up to the task of protecting the engine over the long haul. To be quite honest, the clutch is the least of your worries as the engine will most likely bail before the clutch does.

Long story short, unless you're up for an engine swap, skip cars of this generation with the 2.3 motor. Now, on a positive note, the 2.5 liter Ford Duratec motor is basically the identical twin of the 2.3, but with some major internal upgrades which aid longevity; the Duratec is more powerful, longer lasting, and gets the same fuel economy. These engines were built by the millions by Ford and good low mileage motors can be had for only a few hundred dollars and the swap into the Mazda3 is pretty easy for any decent mechanic. If you want to go that route, I'd offer maybe $1,500 max for the car you're looking at, and then have somebody swap in the Ford engine (and a new clutch while you're at it); then you'll have a car even better than it was when it came out of the factory.

How much would the swap cost me including labor? And is it just an oil consumption/leak issue? Would an upgraded filter housing help? I have heard of these motors going past 200k and more. Are they just the lucky ones? Thanks.

It is the very-very rare 2.3 which makes it past 150,000 miles much less 200,000 miles. If you query "mazda 2.3 failure" the hits you'll get will be sizable.

The cost of labor varies by region and shop; not every shop will be willing to do the swap as they often don't believe the engines are the same. If it comes to it, you can shop 2.5 liter Ford Duratec engines on Car-Part.com and many other sites; once you have the engine in hand you can call around to local shops and get quotes for the swap.

What about the 2.0 motor? Is there any preventative measures to take on the 2.3 to avoid the oil issue? My brother in law has a 2008 2.3 with 148k and he drives it from Utah to California all the time issue free.

As a general rule, the 2.0 has a much better record for reliability. There really isn't anything which can be done for the 2.3 short of replacing it with the Ford motor. There are anecdotal reports of engines, lubricated exclusively with synthetic oil and having had frequent oil changes failing in well under 100,000 miles, there are others which have gone 200,000 miles with minimal maintenance. There doesn't appear to be any common thread linking longevity/early failure.

I read that the plastic oil filter housing is prone to cracking and leaking. And more prevalent is the pcv valve getting stuck causing large oil combustion in the motor. I read that by addressing these two problems, you can extend the life of the motor substantially.

While both true to a point, they will do virtually nothing to extend the life of the motor; the oil journals inside the engine just aren't up to snuff; hence the major internal rework Ford did for the 2.5.

A 2004 Mazda3 S with 130k is probably worth about $3k tops in good shape. Maintenance will determine the engine life. I have an 06 Mazda3 2.3L that uses no oil and as long as you maintain it with quality synthetic oil and changes paying attention to any issues you see, it will run a long time.

I cannot comment on the oil journals comments above, but the Mazda 2.3L has been used on Mazda 3's and 6's for many, many car generations and I believe that proves its reliability.

RGAZ

Well, a huge percentage of the Mazda3 and Mazda6 community would disagree with you there; simply do a search and you will find literally thousands of reports of failed engines.