Auxiliary battery 12 volt with 28Ah

Borderline battery, and/or loose battery connections, and/or parasitic draw.

You'll need to test to figure out and start eliminating the issues above. First, stop disconnecting the battery! Clean, reconnect and ensure a good connection to the battery. Get a jump-box and use the jump points under the hood. That AGM battery is more than likely dried out and on it's last leg. Disconnecting the battery allows it to regenerate enough to close those traction battery relays. Once those relays are closed the aux. battery just sits there and is recharging - if the battery is bad, it can't recharge enough to restart again.

Hope this helps...

 

is the battery 2010?

 

That's the spec? How did that come to be, unorthodox replacement? IIRC stock battery amp hours is a bit over 40.

Kabul, Afghanistan?

 

Weak battery floating up when disconnected. About as borderline as possible.

 

You’re not the first to put a lead acid battery in. The battery will vent hydrogen into cabin, arguably minuscule amounts. How much i don’t know; I’m out of my depth. Also, in a severe crash, there’s danger from acid spill. Again, how much danger is arguable.

I would just carry on, but research AGM battery availability, for future.

 

LoL, don't smoke in the car. No, it shouldn't explode - if it's a halfway decent battery. TAKE MY FIRST SENTENCE SERIOUSLY. Your occupation states that your a pilot, so you know the dangers of H2 or contaminates venting into a tight enclosed space. Air exchange is the key and it may speed up internal oxidation within the passenger cabin.

Your an adult - just be mindful of the safety concerns...

 

hello!

2010 is notorious for a blown head gasket, starting with a very small leak that gets larger over time.

however, it is also possible that you are experiencing the cold startup shakes where unburned hydrocarbons for the last cycle remain in the manifold.
always make sure the car is fully warmed up, and engine off before shutting down the last time of the day.
there is an updated manifold, but idk if it helps any, or if it is available in afghanistan.
all the best!

 

Keep an eye on your engine coolant levels; the coolant tank hanging on the fender - NOT the one hanging on the radiator. If the coolant levels are slowly going down with no visible leaks; you'll need to test for head gasket integrity (compression & leak down test). Use a marker or tape, a slow leak could take a few weeks to a month for the levels to change, where it's noticeable.
Have your friend do the same, as bisco stated - these model years are know to blow head gaskets.

Hope this helps....

 

I don’t think there’s a code for the head gasket, it’s a fairly complicated test

 

Once it’s really gone you’ll get P03XX, with XX sub’d by 00 through 04. 00 being general misfire, and 01 through 04 being cylinders with misfire. It’s typically 00 and 01.

also could be P0401, EGR flow reduction.

but usually after the head gasket is already leaking coolant.

 

IMHO, When you catch this stuff early and take care of if it; BEFORE the computer starts throwing codes - the less likely you'll damage other parts of the engine (ie. bent rods, hole in the side of your engine, warped heads). The repair will also be cheaper; though labor cost over there is pretty inexpensive - it's quality of parts and availability that's the problem on your side of the pond.

Hope this helps....

 

And if you want avoid this stuff happening, clean the full EGR circuit, every 50k.

nobody buying these cars, back in 2010~2015, saw this bs coming, but here we are.

and Toyota doesn’t want to know about it, so apart from a few shops that know what they’re doing, it’s DIY.

 

You have a blown head gasket but on this car it does not 1) make the oil milky 2) show up on a coolant combustion gas test 3) cause the coolant to drop for months or 4) throw misfire codes because it initially clears quickly.

It is a big problem because it can bend piston rods, blow holes in the block, ruin the engine damper and eventually months later cause the engine to overheat.

Most diy’ers and mechanics will throw much money into it with new plugs, coils and injectors plus clean or replace egr coolers without success although new plugs often give you a week or two of good starts.

A quality borescope inspection in the hands of an experienced person can often see a steam cleaned piston.

If it’s already burning oil as well (common on these engines) a rebuilt replacement engine with revised pistons and rings is the longterm solution, which of course includes new gaskets.