Just chinning in and hopefully not diverting from the ongoing conversation. Not often times is insomnia really rewarding but this night I was chewing through some Youtube videos only to stumble on this interesting episode of Chris Harris about a legendary Le Mans cars, the Porsche 962 from the 90's....

When changing to synthetic, I would keep a close look at the oil level. I'd check it no later than each week, even sooner at the beginning. My car drunk oil like crazy when I switched to synthetic, for the first 1-2 oil changes, then the level got stable back again

How many km ? Try first replacing the oil gradually (not all at once) with the 3309 type - can get it from a toyota dealer Toyota Type IV. Read online how to replace it, there are many topics on forums about this.

So it's not because of switching to synthetic - I assume the oil consumption started only recently. The 2010 models (P3 as we call them) had a widespread PCV problem causing the engine to start taking oil at alarming rates with low miles. The PCV box is located at the top of the engine and easy to r...

Don't think it's coincidence. Try to lock/unlock the doors three time with the key fob, but not much hope It may happen on these XC90 the thermistor behind the small grid on the CCM face to blow when the battery is connected/unplugged without the key in POS II. Don't know how to check this, but not ...

Between the moment when you adjusted the plug gap and was idling fine, and the moment it didn't start, was the car at the garage? Did the mechanic work on it? Also good to know that the plug gap is a very sensitive thing, really just slightly out of gap and it can go crazy. Shaking is serious misfir...

One thing, use care when removing the door speakers. They have a while sticking seal on them, if this seal is not in perfect condition, water will leak from inside the door, into the fool well, underneath the carpet

Thats the automatic. So you can put the automatic button either on - green light, or off - red light. Look first near the right temp knob, behind the grid is the cabin temp sensor. Put the vacuum on it or blow some air but dont touch the sensor. Next try the calibration mentioned, is it done with th...

The throttle body (is that what TB refers to?) cleaning sounds a bit out of my realm. Maybe not, but have never done this. Unless you mean just squirting in that cleaner and revving. That I can do... It's easier than replacing the air filter. Just undo the screw clamp at the large hose on the throt...

Lean running can cause hot top engine end. It can damage the ignition coils. Maybe keep the engine cover removed. The thermostat can also fail closed and cause overheating on the 3.2 Worn spark plugs can also damage the coils. Are you using genuine coils?