Maybe it's just that it's been winter and cold and I've had the Tracker all closed up so I didn't notice it, but it seems that all of a sudden my valve seals have failed.

Any body else experienced this?

After idling for a few minutes, It gives a puff of blue smoke upon acceleration. Sometimes at startup. No smoke any other time. Oil level doesn't diminish.
Man, it's annoying!

Is it possible that one (or more) seals came loose?

The engine has 145K on it, runs strong and whatnot, just developed this. Hopefully the valve guides are OK!

I'm still getting 26 -28mpg average, so I think rings are OK, but I'll do a compression check this weekend just for fun.

Sounds like valve guide seals. 8 or 16v? Do a search, you'll find it's been gone over a few times.

16 valve.

Yeah, I searched it (guess you have to start each post saying so any more!)   
Nobody speaks of sudden valve seal failure.

I know how to do the procedure and what's involved. I guess the reason for my post is the suddenness of the whole thing. One day, perfect engine - next day, puff of smoke.

I was just wondering if this is common with this particular motor, or if there is another underlying reason for the seals to go kaput.

Actually, now that I think of it mine did almost the same thing,  or maybe I just finally noticed it one day. In any case it came on pretty quickly, and It's most likley just one or a couple of guide seals. It's a real PITA to try and replace them with the head still on the motor, I did it, but would pull the head next time.

It's a real PITA to try and replace them with the head still on the motor, I did it, but would pull the head next time.

Really?! 

Damn, I was thinking it would be way worse to pull the head. You've obviously done a lot of wrenching on your Tracker. Just wondering what made the job so bad that you'd rather pull the head? 

You really have to with the 16v, the valves are deep, and very close to the wall, makes it almost impossible to get a compressor around them. They don't normally wear out slowly, what will happen is they dry up on the exhaust side and crack causing the leak. It's just a small crack now, but it will get worst, and you'll notice being a quart low every couple fuel fills. I attempted mine with the head on a couple weeks ago and found out the hard way, now I'm pulling the head tomorrow to try again.
Something else, there is a rod that goes in through the front of the head for the valve rockers, it has to come out - I didn't see a way of pulling it out without either pulling the head, or lifting the engine.

Ugh.

Looks like I may as well buy the gasket kit and a 12 pack. 

Believe me, it's worth it to pull the head. I did manage to replace all my seals with the head on the motor, but it required actually MAKING tools that fit the head, and reaching into the engine compartment to do it is just too damn difficult. Pull it.

OK, a little light reading in the Haynes manual and I noticed that, in order to do this with the head on the motor, you're supposed to remove the grille, hood latch, and upper member - blah, blah, blah... 

I've changed my mind. I'm pulling the head! At first I thought you guys were crazy, but now it does look simpler to remove the head. Guess I was trying to avoid the gasket set (I'm cheap)! But I found sets on eBay for about 1/3 what the auto parts stores want.
Anybody had any (bad) experience with these?
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=300215462379&ssPageName=STRK:MEWA:IT&ih=020

I got my my head gasket, intake gasket, crank seal, cam seal and timing belt from Altrom, a local place to get import vehicle parts. I got my valve seals from an engine rebuild shop. Total cost was about $120. Plus another $30 for redbull, beer and pizza

My buddies 1.6 Sidekick started looking like a 2 stroke one day.
I just talked to him yesterday and asked him what he did to fix it...
he responds with "Filled it with 91 and gave it a shot of Lucas!" I didn't see any blue smoke...but it was night time

Amilla