2010 Tundra Head Gasket Leak Drama

ok, I’m new here so I appreciate any help here.

2010 Tundra 5.7 262k miles

For the last 2 years I have intermittent crank no starts....finally 2 months ago it throws a code, #2 misfire. Replace coil and all plugs...Denso oem.....take truck home and it sits for a month on and off. Other day #2 misfire again.....wtf...take it to a Toyota specialist that was recommended to me. They check for oil leak onto the coil, no leaks, check ECU and fuel injector, all check ok. Drive truck with live data running and 62 misfires upon start up.

Looks like a small head gasket leak. Truck has never over heated, ever. Toyota Pink it’s whole life every 50k. Interestingly the mechanic noticed that the over flow reservoir was slightly low and there are a couple of very small cracks in the radiator.

No oil in coolant and no coolant in oil. No smoke on start up. No rising oil levels. Etc...

He said I’ve never seen a 5.7 with a head gasket leak outside of supercharged units. He calls his buddies at the 2 big dealers in town and they agree this is very rare. Like they’ve never seen it either outside of abused units with blowers.

His theory is that when the reservoir was drawn down low a small air pocket formed at the right time and the right place to create a small leak. He also said that since we caught this early it’s probably not blown and thus no coolant in oil and vice versa.

He has had a couple of the 4.0s do this and he has used a sealer, not blue devil or steel seal, comes from Japan and he has seen great results and they are holding strong 2-3 years later.

We are trying this currently.

I have scoured the internet including Ih8mud and literally I have found maybe 3 other 5.7s do this.

What do you all say?

Thanks again for your help and hospitality to a new guy.