A friend reached out to me recently, panting over the phone. “Throttle!” he shouted. Where’s bank 2 of my car? I can’t figure it out,aand the research online isn’t helping matters!”
Calmly, I asked what make and model he was dealing with.
“It’s the same vehicle as your Lexus, don’t be silly!”
I responded: “That’s a transversely mounted engine – there’s only one way bank 2 would be and that’s the radiator side.”
“Thanks a million,” he offered. “There’s more to this though: how did you know the right answer off heart? And what do the ‘passenger side’, ‘driver side’, ‘left’, and ‘right’ mean?
I asked him to come along with a bottle of my favorite drink and I’d explain everything to him.
Luckily, you don’t need to do anything to benefit from my knowledge today: continue reading, and I’ll be happy to explain everything to you so that you won’t ever look confused when engine banks are mentioned.
If you missed the first part of this entry: Where Is the Bank 1 on the V6 Engine of the Lexus ES330?, it makes sense to read that bit first.
Article Outline
Transversely vs. Longitudinally: A Game of Placements
I was able to tell my friend, right on the phone that the FWD intentioned 3MZ engine was transversely mounted so it has its bank 2 on the radiator side of the engine because I understand engine designs and what they ultimately mean.
Understanding how engines are designed and mounted will help you immensely as you begin the process of mastering your banks.
So, what are the two, general mounting styles we have today in most regular vehicles? Transverse and longitudinal.
Transversely Mounted Engines
Transversely mounted engines are mounted from side to side of the engine bay, compacting everything into a nice, good package.
Front-wheel drive (FWD) setups are the most popular candidates for this type of engine mounting.
For transversely mounted V6 engines (like the 3MZ in question here), there are two banks: one on the firewall side of the engine bay and the second on the radiator side of the engine.
Longitudinally Mounted Engines
Besides the style of mounting an engine transversely, there’s another option of mounting an engine longitudinally, usually, with the crankshaft in the direction of travel the vehicle must drive.
Popular with Four Wheel Drives (4WD), Rear Wheel Drives (RWD), and All Wheel Drive (AWD) systems, this type of engine mounting typically runs the length of the engine bay and ensures (near) perfect weight distribution.
For longitudinally mounted engines, the banks don’t typically face the firewall or the radiator sides; instead, they face the driver or passenger sides. For these configurations, ‘driver side’ or ‘passenger side’ is used when referencing the bank in question.
Please, note that for the time when ‘left’ or ‘right’ sides are used, what I’m using as a reference point is a left-hand drive vehicle with the passengers seated and facing forward.
From the above now, you can clearly see that an engine’s bank can either be on the firewall or radiator side; driver or passenger side.
Where Is the Bank 2 on the V6 Engine of the Lexus ES330?
The 3MZ from Lexus is a transversely mounted engine and has bank 2 on the radiator side of the engine, as already noted. Assuming, however, that the engine was mounted longitudinally (in a left-hand drive vehicle and Lexus kept things the way they currently are), bank 2 would have been on the passenger side.
Once you know these basics, you’ll be able to tell which bank is which and importantly, handle bank-related matters such as 02 sensors and ensuring Top Dead Center (TDC) when trying to figure out your timing (with ease).