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Discussion Starter · #1 ·
Here's a strange one I encountered. When traveling 65+mph and the EV mode switches to HV after the battery runs out, I would feel a pretty good amount of vibration. It would happen only when my wife was using the car, so I only experienced it once (with her in the car). After taking it in the dealer couldn't replicate it, as I expected because I wasn't able to produce it driving it myself.
The tech did discover the air filter cover wasn't installed all the way and 1/2 the latches weren't on. Turns out when the engine experienced a higher load, i.e. 65+mph and the AC was on (wife always has it in auto), the air-fuel ratio was off because of the ajar cover. This caused misfiring in the engine and as a result, the vibration. Since this always occured in such a short amount of time, and so rarely that the check engine light never came on. The tech was very surprised it didn't throw a code. The air filter has never been changed, and he said it looked brand new. It might have been partially installed from the factory so I'm impressed we made it almost 3 years before having the issue.

Here's to hoping no one else runs across this issue, but if they do I hope this helps.


Tim
 

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I haven't looked that closely at the Clarity's engine air intake ducting but the only way a loose Engine air filter cover could cause problems is if the MAF (Mass Air Flow) sensor was being impacted. MAF sensors are usually on the engine side of the air filter so as the filter starts to clog the engine's computer system is provided consistent information. The only thing I can think of is the MAF wasn't properly reporting rapid changes in air volume due to the filter cover opening and closing slightly.

As a routine maintenance item, I check the engine air filter every spring - it's a 10 minute operation. I highly recommend everyone do this.
 
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I agree, I haven't looked into it at all but I agree with your knowledge of the MAF workings. All I can say is that it worked, and we had no vibrations over 900 miles of HV driving with AC on.
 

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I checked my air filter housing when I got the car home first day. I had that happen in a car years ago and pulled my hair out (and wrote a very nasty email to Toyota) before I was told by my neighbor (who I was also complaining about it with) found it in about 3 seconds. I check that, the oil filler cap and the dipstick just to be sure.
 

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I check that, the oil filler cap and the dipstick just to be sure.
And tire pressures. And not necessarily for low tire pressure. Tires are often overfilled at the factory so that they won't deform from the car sitting for a long time during transport. The dealer is supposed to reduce the tires to the correct pressure, but many people have checked their tire pressure after purchase and found them to be way too high.
 

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And tire pressures. And not necessarily for low tire pressure. Tires are often overfilled at the factory so that they won't deform from the car sitting for a long time during transport. The dealer is supposed to reduce the tires to the correct pressure, but many people have checked their tire pressure after purchase and found them to be way too high.
I went to perform my semi-annual top-up of the 12V auxiliary battery two days ago, and I found that the negative battery terminal clamp was not tightened down. It was actually the first time I had looked under the hood in the five months we've had our '21 PHEV Touring. (Crazy, I know, especially for an avowed "EV Nerd".) I could easily spin the clamp around. An intermittent disconnect on that could have caused all kinds of mysterious issues. I tightened it down with a trusty little 10mm open-ended wrench. (10mm is pretty close to being a universal nut size on battery clamps.)

I suspect that these vehicles are shipped with the 12V auxiliary battery ground disconnected, for a lot of reasons. It certainly should have been corrected during a pre-delivery inspection, using a checklist.

I think I'll spend a half-hour or so today, giving the engine bay a much closer inspection.

There are no excuses for Honda to have missed these things. None.
 

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I went to perform my semi-annual top-up of the 12V auxiliary battery two days ago, and I found that the negative battery terminal clamp was not tightened down. It was actually the first time I had looked under the hood in the five months we've had our '21 PHEV Touring. (Crazy, I know, especially for an avowed "EV Nerd".) I could easily spin the clamp around. An intermittent disconnect on that could have caused all kinds of mysterious issues. I tightened it down with a trusty little 10mm open-ended wrench. (10mm is pretty close to being a universal nut size on battery clamps.)

I suspect that these vehicles are shipped with the 12V auxiliary battery ground disconnected, for a lot of reasons. It certainly should have been corrected during a pre-delivery inspection, using a checklist.

I think I'll spend a half-hour or so today, giving the engine bay a much closer inspection.

There are no excuses for Honda to have missed these things. None.
Honda doesn't miss these things. Dealerships do. Remember, legacy auto doesn't own any dealerships.
 

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And then there are the infamous body plugs. Grommets really, there are four of them that plug some holes in the underbody. Not sure why they aren't installed at the factory, instead they are left in a plastic bag in the glove box for the dealer to install. Maybe they are left off to provide some ventilation for a few weeks so that some coating inside can dry, or something like that.

Not all dealers install them, more than one owner found them in the glove box and installed them themselves. Although they say they didn't notice any difference in cabin noise.

Note that there are some underbody holes other than those shown in the diagram below that aren't plugged, presumably that is by design.

Motor vehicle White Line Font Engineering
 
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