Hello,
Recently my wife (Debbie) and I have begun the process of purchasing our first home.
If that's going to happen I need to make sure the trusty Montero remains trusty for another 100K or so.
The clock is currently 166K+, and on the surface it runs quite well. Debbie believes everything is perfect. The problem is I have to add a quart of oil about every 500 miles.

It does leak some, but I'm fairly sure it burns just about as much.
I've read several posts regarding the valve stem seals, but there seems to be a wide range of opinion on the difficulty of the job. I consider myself to be fairly capable. I undertook the timing belt job armed only with my tools, a Chilton manual and this site.

I would like to put together a good collection of steps/tips to do the valve seals, and also suggestions on other seals/gaskets I can change in an effort to eliminate or at least reduce the oil leaks. I've taken a quick peek at the rear cam seals - passenger side does appear to be leaking, couldn't get a good view of the d/s.

Thanks to anyone who can help

Do both of the rear cam seals for sure. I had mine done by the dealer. I was uncomfortable with all of that oil dripping on the exhaust system.

There is a good write-up on the rear cam seals at www.monterosportonline.com

1qt per 500 miles. That is a lot of oil.

Have you done the spark plugs? How about drain and top-up the tranny? Flush the brake fluid lately? All good preventative maintenance. (well, except the spark plugs)

I recently saw a nice write up on the rear cam seal replacement. That's why I took a look at mine, from the little I could see it definitely looks like I have a leak there. From what I can tell it seems like the valve cover gaskets might be leaking too, and possibly something behind the timing belt covers.

Did plugs and wires -- oh, maybe 60-70k back.
Drained trans completely/replaced filter around the same time.
Haven't flushed brake fluid - I'll keep that in mind.

I'm most concerned about the stem seals. I think I'll be fine on the rest of the repairs.
I shouldn't have any problem getting down to removing the valve covers. After that I'll be doing a lot of head scratching.

If you can do a brake job yo can do valve seals. Figure on about 5 hours of steady work your first time.

It's tedious, but not that complicated.

Clay

I'm willing to tackle this job, too. I've yet to buy a manual, so having a Chilton give me enough info? Is there any combos of "how-to" to approach the job?

Yeah, that's about the way I see it. I've done the brakes. Replaced all 4 rotors not long after we bought it, and have replaced the front pads a 2nd time since then. Also replaced the left outer cv boot which was educational

I'll have to do some manual studying and see what other questions I can come up with.

Kind-of off topic. A tip regarding the spark plugs. First a bit of history. When I changed my spark plugs last time, I inspected them carefully and noticed that the three plugs on the drivers side had significatant wear on the ground electrode while the passenger side plugs had very little wear on the ground electrode. I did a bit of internet research and found that our coil design (one coil powers two spark plugs) causes one plug to wear on the center electrode and one to wear on the ground electrode. The center electrode is a bit more resistant to wear than the gound electrode. So, if you swap your wires on each coil you will change the wear pattern on plugs. Once you switch the wires the passenger side ground electrodes will start wearing. I think this will allow you to get a bit more life out of your plugs.

So, after all that blather, you should try switching your plugs wires (at the coils) to extend your plug life.

I have to wonder if more severe oil consumption is indicative of problems beyond the valve guide seals.

In my case I was clearly burning a lot of oil, judging by the blue fog that surrounded my truck on offroad trips. I had the valve guide seals done. Unfortunately, in my case it did little to reduce my oil consumption.

About six months later, I went ahead and replaced the heads with Clearwater heads. This took care of the problem completely. I do not know if there is a way to tell if doing the guide seals alone is not enough, but it is something to consider.

Since you say you want to keep this rig running for another 100K you are probably going to need to replace the heads at some point. It is a much more time consuming job but you could probably do it yourself and be more sure that the engine is good for another 100K.

Some may disagree but it is at least worth considering.

I'm not surprised to hear that suggestion, and I'm aware that valve seals might not be the (only) problem, but I'm willing to throw this dart in an attempt to fix it before I part with hundreds for new heads. Plus - If I do decide I need new heads I will probably feel better about the job having done the seals previously.

Leaks are substantial - the trans is ALWAYS soaked. If I can stop most of those, and make some improvement replacing old valve seals I would like to think the oil consumption would be improved significantly.