The thought just occurred to me. I'm sure other people have thought of this as well. Say you have a 6 cyl car, and 3 deactivate. Is this going to be a problem after say, 10 years, because of uneven cylinder wear and deposits since the same 3 cylinders always deactivate? Will the engine feel unbalanced after a long long time?

 

as far as i know the same 3 dont always deactivate,and even if they did they wouldnt get any deposit build ups, since no fuel or spark is going into them, just air in the chaimber. and im sure its been taken into consideration, (especially by honda)

 

Oh, I didn't know it wasn't the same three all the time. I was just thinking that if it was, one bank of cylinders would have more deposits than the other. I'm sure you have to be careful with the break-in period on these cars, unless the cylinders refuse to deactivate until you've driven XXXX distance or something.

 

it may be the same 3 all the time but like i said, since fuel and spark are cut off there shouldnt be any deposit build ups. the piston is still going up and down scrubbing the cyl walls just with out spark. if any thing the other 3 would have less life, but im sure its negligable

 

You're right. At the very minimum, it would last just as long as a regular engine. If the three cylinders shut off regularly, the engine could last much longer, especially if the cylinder banks deactivated alternately. I think in the Accord Hybrid, the rear bank is the one that always deactivates.

 

well dont the deactivated cylinders continue to move up and down, they just dont get fuel and spark, right?

 

Wouldn't there be a greater load - and consequently more wear - on those cylinders that aren't deactivated than if none of the cylinders were deactivated. It would seem that the engine would wear more slowly if all cylinders participated equally and shared the load imposed on the engine equally?

 

You bring up a good point. If the same bank gets turned off each time, then they are going to wear differently. Depends on how much highway driving you do...one bank could have 20-30% more wear than the other...possibly making the engine lopsided as well as bringing up other problems.

It boggles the mind!

 

Yeah, those were my initial thoughts. Now I don't know what to think.

 

Ugh! Why am I so damn slow??? You beat me to it!

 

I don't think that's the case. Once the load becomes too much, the IMA helps out, or else the other three kick in (in non-IMA vehicles like the Odyssey). I do think though that the uneven wear in one cylinder bank might cause issues.