This morning my fears were confirmed. For the past several weeks my 02 (195k) has had a cold start misfire and thrown the p0300 code. I also noticed it was slowly losing coolant.

I returned from a 2 week vacation yesterday, fired it up after sitting for the longest it has sat without running in years. It billowed white smoke from the tailpipe for quite a while, this is the first time I've seen it smoke but I'm assuming thats because it typically would only sit for 6-10 hours at a time without being started again.

So I've got to assume I either need a head gasket or have a cracked head.

I can't afford to go out and finance a new vehicle right now, and I think going and buying a beater for the cost of having my 4runner fix might just get me a piece of crap that needs a ton of work (unless I got super lucky.).

I'm thinking my best bet is likely going to be to have my t4r repaired. I haven't spent a ton on repairs since buying it about 6 years ago, so maybe its worth it to just keep it going. It hasn't been overheated, so hopefully its just the gasket. I assume the heads should come off for inspection by a machine shop. I'd also consider swapping a motor from a wrecked rig if there was reasonable confidence it would run well.

Anyway, I know many shops near me may not even want to touch the job, and many will quote me an astronomical number. I live in Summit County, Colorado.

Any yota mechanics based in Colorado here on the board? I thought this might be a good place to begin the search to find someone to take on this job.

Check ypur plugs to see which ones sre clean. Check your oil if it's mixed with coolant it will have a brownish color. Does the engine over heat. Buy a harbor freight compression tester or borrow from loan tool program do a compression test. .When was the last time the engine intake gaskets were replaced? You can buy a kit and test for exhaust gas in coolant. If you dont want to trouble shoot and are convinced that it's the motor Then a new rebuilt around 5k, Jdm around 3k, Cheaper option, Toyota pros or Jims yota yard in Denver, for around a grand and if you can't do the install your self another 1000 for labor. Also Craigslist. Prices might be higher now.

Having gone through a similar situation on mine, I will second this advice and suggest that you eliminate any question at all about it being a head or head gasket, before you do anything about it.

I felt completely certain that mine was blown, until I disproved it with an exhaust gas in coolant test kit. It turned out that a faulty injector was causing my misfire, and all of the other symptoms of a blown head gasket I had at the time were coincidental (as well as minimal). That was 5 years ago, and mine is still running strong. I have done other work on it in the meantime, while replacing the timing belt, and that may have eliminated some of those coincidental and minimal "blown head gasket" symptoms.
Research and test that P0300 misfire until you know without a doubt what is causing it. I forget the code I was getting, but swapping coils was one thing I did that eventually proved that it was an injector. $50 eventually solved that problem, instead of the $1.5-5k that may not have solved it.

Some of the things I mentioned that were minimal and (likely) coincidental were that mine had lost a little coolant, smoked a little on startup, with what smelled kind of sweet. Perhaps I was also seeing exactly what I was looking for, which is human nature to do.

I have learned the hard way that very often, things are not at all what they seem. I would hate to know that someone had HG's alone, or heads/HG's replaced, only to have the problem persist, and I know I would have been beyond pissed, and felt like a complete idiot, if I had done any of that and still had my misfire.

In summary, I suggest that you be 110% certain of exactly what the problem is, before you do anything to solve it. Not merely 90-95% certain.

No coolant mixed with oil, or vice versa. Intake gaskets have not been replaced since I've owned the vehicle (About 6 years and 70k miles or so) and not sure about its past maintenance.

I have a leakdown tester I bought from harbor freight before I took off for vacation - had planned to do that to establish if I have a headgasket issue before throwing more parts at it. So far all I've done to attempt to address the misfire is plugs/wires and taking off the TB and cleaning out all the carbon. Yesterday when it was blowing white smoke after sitting for 2 weeks I figured that was all the confirmation I needed (no smoke up until this point had kept me hopeful it was something else - despite the slow coolant consumption.). I suppose this weekend I should go ahead and do the leakdown test before assuming it is a HG.

I thought I had a blown head gasket with my 2001.....loosing coolant, smoke when start up, misfire code. Did a compression and leak down and that was all good, did that radiator test for exhaust gas...passsed.
Ended up being a bad coil, needing plugs real bad, and the coolant leak was from an after market block heater that was seeping.
So dont give up yet on your engine.

also maybe you can find help here https://www.toyota-4runner.org/mountain/

4Runners are known to put on a steam show on cold or damp mornings that mirrors a failed head gasket. The exhaust also has a tiny bit of sweet smell to it. I noticed that the first week I bought mine 7 years ago and hasn't changed. Especially when the engine gets bone cold after sitting a few days.

Now the coolant loss is more disconcerting, as there's only so many places it can go. The leak down test will give you a definitive answer as that's hands-down the best way to check for a failed gasket.

I'd add with the spark plugs also check the tops of the pistons if able, maybe a bore scope would help if not. The piston head should have carbon build up, if one or two is shiny those will likely be the source. I had similar issues as you described and after taking it apart both heads had small cracks in the middle cylinder between the valves, #3 being the worst. I ended up getting two new heads for ~1100 at local shop in Oregon after returning cores. And a decent bit more buying new tools.

And to add it had a similar smoking pattern of being fine when warmed up and a good bit of white smoke during a cold start, but I would still look to rule out any other possible issues before assuming the worst

The leak down test is the way to go. When the HG went on my 97, I tried all of the "tricks" to test for bad HG (exhaust gas die test thingy, pulled plugs, bore scope etc) and they didn't indicate a bad HG. Once I did a leak down test (pressurized cylinder #3), I had air bubbles coming out of my radiator. Case closed.

Good luck either way!

Well... i got around to doing the leakdown test. When I pulled the plug for cylinder 4 I found the threads soaked in oil. Pressurized the cylinder, bubbled out of the radiator. Oof.. didnt expect this at just under 200k!

Sorry to hear that.

On mine, with 206k, if she blows (HG), I will just sell it that way, with the problem disclosed, and take my loss. Might be smart for me to sell it now, before that happens, while it is still worth $4-5k. That'll probably drop in half with a blown HG.

The only problem, and why I continue taking the gamble, is that replacing it would cost a freaking fortune that I do not have. No way in hell can I ever again buy a vehicle that will do what my T4R does, for $9k, drive it 14 years, and have it still worth half that. Nowadays, a $9k T4R around here is a later model one, but has 250-300k on it.