Coolant In Cylinder

[Jonny]

A little while ago my previa would have a misfire on start-up and I quickly found out I had coolant in the exhaust system.
I stopped driving it and removed the engine and head expecting an obvious cause.
Well, there were a few ounces of coolant sitting in cylinder 2, but no obvious (to me with the naked eye) signs of cracks in block or head, and the head gasket looked great with apparently still good seals around the cylinders.
I took the head and gasket to a shop I trust and they couldn't see any clear cause of the leak either.
The oil quality looks great - I'm pretty sure the leak goes only from coolant system to cylinder. In fact the engine looks to be in really good condition otherwise. The cross hatching is still there in all cylinders, no scoring. I took off one rod end cap and the bearing surface looked as good as new, so I'd like to keep the engine and just repair it.
I'd like to diagnose this myself but I've lost confidence in my ability to find the cause of the ingress.
Any suggestions as to how I might proceed?

[Previologist]

Maybe @pdgizwiz knows something, he seems to like tearing these engines apart. Are there places where head cracks could be hidden in small passages or something? I have definitely heard of head gaskets in other cars leaking without visible signs, but I don't know how reliable those stories are.

[originalkwyjibo]

Can you post a pic of the head gasket?

[Jonny]

First 2 are the head side, last 2 the block side.
For some reason the resolution on my computer jpeg files is great, these imports not so much. Is there anything I can do to get the import quality up? I use the "insert image" icon to upload my photos.

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[originalkwyjibo]

There's certainly nothing glaringly obvious there.
I had a 1979 Honda Accord that had been neglected badly and had a suspected headgasket leak similar to your situation with no obvious breach. It ended up having pinholes in the head around an intake port likely from dirty and acidic coolant eroding and corroding it's way through over the years.

[Jonny]

How did you discover these pin holes?
I must admit at this point I'm considering taking it to a head shop for a professional diagnosis, crossing my fingers and hoping they're honest and know what they're doing.

[originalkwyjibo]

I took it to a local machine shop and had it pressure tested. Any time I've dealt with a blown headgasket on any vehicle I've had the head pressure tested(or magnafluxed if it was iron), had the surface checked and remachined if necessary, and the valves reground. Maybe yours doesn't warrant all that since it didn't actually overheat and blow the gasket but it is off and may be cheap insurance in the long run. If it were mine, I would at least get a pressure test.

[man_btc]

I did the same with mine (except left the valves alone) when I did the head gasket - if there's anything more aggravating than putting all the work in on this, it would be having to immediately do it all over.

[tbkilb01]

mine popped and I saw smoke...checked water level and drove home. I relaced gasket in backyard. inspected pretty close and even valves held tightly against liqiuds. removed engine mounts and fished out through passenger sevice door. put gasket on and took Radiator in to rod out..put dizzy in wrong and didnt startbut Timserv came to rescue and had me check dizzy... he was spot on! she fired up first try after adjusting... drove to Carolina from louisiana ...no problems. still fires up today.

[Jonny]

Well, after months of despondency-induced procrastination, I finally made the effort to confirm whether the head is cracked or not. Yes, it is. I did a DIY at-home pressure test, which was pretty rinky-dink, but it did the job of confirming the crack/leak and I am going to do a thread on it. Some of the more experienced on here might find it pretty funny, and the inexperienced, like me, might avoid the mistakes I made. Also, thank you all for the feedback, above.
https://www.toyotavantech.com/forum/showthread.php?8852-Cylinder-Head-Pressure-Test-DIY