Hey all, I've lurked here a while as I have a 2009 HCH and typically solve problems myself, unless special tools or experience is needed. I just wanted to compile a list of things which similar owners may want to watch for. Right now, the car is more enjoyable than it ever has been since I bought it used many years ago. I recently hit 163k miles and would love to hit 250k. It's honestly a pleasure to drive!

1. Regular oil + filter changes. I do it once the maintenance minder hits 10-15% oil life. Super easy job. I replace the filter each time. Maybe 30 minutes in my parking lot. Full synthetic 0W-20 + filter is cheap!
2. Somewhat regular CVT fluid changes. Only use the official Honda fluid or the CVT will hate you. For a while, my CVT was just a little jumpy or jerky occasionally. I didn't know how the previous owners had cared for it. So, I did a full flush, which entails a drain, fill, and drive, repeated 3 times. Because each time you drain, some fluid remains inside. Now, my CVT is super smooth and satisfying to drive. I will replace the fluid again after say 30,000 miles, just as a preventative measure.
3. Replace spark plugs. I've had the car for many years, and the manual shows maintenance minder should tell me eventually to replace them. I went ahead and just did it, and the engine feels much more 'sure' of itself under load. This is particularly noticeable when accelerating onto the highway >3k RPM. Really smooth now! Old plugs were clearly worn but otherwise clean. Back 4 plugs are hard to reach, and will require a couple extensions of just the right length to get in there. I used the ones recommended in the manual. Rather pricey, but the car feels so much better after replacement that it was totally worth it.
4. Replace brake pads. Also super easy, just do it yourself. I would say don't get the cheapest pads because they just end up wearing down much faster. My brakes are totally quiet, and the braking power is impressive.
5. Tires. Always stuck with Michelin Defender's (nice all-season with low rolling resistance). Got them at Costco mounted and balanced cheap. I know they say 32PSI but I keep things around 38PSI for slightly improved MPG. Rotate them yourself with every oil change, very simple to do.
6. The high voltage battery! It had been replaced under warranty when I first got the car. But recently, it was obvious that it had failed even though the firmware update they did the first time clearly silenced the code throwing, along with reducing how aggressively the assist is applied. Basically, the battery sucked, but the car stays silent about it, other than showing constant re-calculations and loss of IMA assist often at the worst times. I replaced it with a Bumblebee performance battery, and it is so much better now. MPG's are going back up, and I have nice long assist up big hills. Regeneration feels like it should again and ramps up with more confidence. High-voltage A/C compressor is always available to assist with cooling, whereas it used to not run much.
7. The low voltage (12VDC) battery. For a while, I was living in a much colder climate, so cold that in combination with the bad high-voltage battery, the conventional starter would sometimes engage to start the engine instead of the IMA system. So, I actually installed a slightly-larger 12V lead-acid battery than the stock size. No worries, it is safely mounted. But now, in concert with the custom audio system I installed, this has given me good reliability. (I have a lot of additional drain on the 12V system from various custom accessories, including cameras, speakers, subwoofer, radar detector, VHF/UHF amateur radio...)
8. The A/C system!! This one evaded me for a while, as my cooling capability slowly reduced to the point where it was almost useless. Now, I'm talking over the course of like 5 or more years. I realized there is a very slow and small leak on the high side hose coming from the compressor. Must be quite small to take 5 years or more. Also noticed the high condenser fan speed wasn't coming on any more. This is because the high-side pressure never got high enough. I'll be having that hose replaced soon. But for the time being, I recharged the system with (only straight) R-134A and a hose plus gauge set. $20 fix and I only used a little over half of a 12oz can, while the system targets 14.1~15.9oz total fill. Let the car run with A/C on full blast recirculate on a hot day. At idle, it was obvious my low side was low on pressure. Added gas until the low side at idle was in the green range. When you rev the engine, up to around 2500-3500RPM, the compressor will run faster in unison with the engine until it disengages, to give full power to the drivetrain for acceleration. You need to add more gas until the low side stays in the green at 100% compressor operation when in this range. My A/C is ridiculously cold now. Do not add too much refrigerant! You should never go in to the yellow area of the gauge at all. Another interesting thing I noticed, is that the auto-stop feature triggers far more often now. I think before, the car always thought it was failing to satisfy cooling call from the cabin. Now, it's very satisfied and auto-stops even when it's 96 degrees outside. (The high-voltage compressor can be heard engaging during this. Nice!)
9. Coolant. Really easy once again, just let it drain out the valve at the bottom of the radiator, and add fresh to the top. Did this once the maintenance minder said so. You don't really need special coolant, but follow the manual and don't use stuff not made for your car.
10. Brake fluid flush. Easy again, just DOT-3 fluid and open the bleeder valves one at a time. My fluid was quite clean, but good to keep this up so you have no corrosion of the brake system.
11. Center console cover tab. It broke at some point. Super cheap part online. Just screw in back on.
12. Windshield. Because the front glass on this car has such a slanted angle, rock hits are far less likely to crack it. However, after countless big rock hits, one finally managed to crack mine. Had it replaced by Safelight. Pretty cheap but I probably could have gone cheaper with a shop. Eh, it was convenient.
13. Engine and cabin air filters. Manual shows that maintenance minder should tell you to do this. But I have yet to see it. And so I went ahead and replaced both. Once again, they were pretty dirty, especially the cabin filter. Saw a few nuts and junk in there from a mouse most likely. Better airflow means my vents blow with more volume now! I would recommend keeping the air system on recirculate when you park your car, to limit the ability of animals to climb in to the outside air intake!
14. Wipers are so easy to replace on this thing. Just get them online and swap the old ones out. I did have to adjust the wiper range after the windshield was replaced, because the guy did not replace the wiper to the right place on the wiper motor.

So of course we can talk about cost, and how that expensive new battery was 1/4~1/2 the private party sale value of my car today. If I traded it in, it would be the entire value of that battery. But, for me, this is a car I have decided to keep running until it just totally dies. I'm doing all of this work myself, so it's honestly been a great learning experience, and has kept the maintenance cost way down along the way. The thing is just so reliable and cheap to operate. My goal is 250k on it. Then, I can allow myself to splurge on a fully electric car. Likely a Tesla Model 3 or Y. And I'll probably still keep this thing as a backup, just driving it every week as it's such a simple car.

Finally, I'd like to ask, what are some other things I should be doing to this car? I have seen that the EGR port can become clogged. I don't notice any symptoms of that however. And no codes are being thrown. Cheers to the HCH and this forum!

 

Agree, with the following commentary:

2) CVT fluid changes every other oil change, or about 15K miles.
5) Bridgestone Ecopia EP422 Plus
7) 51R instead of stock 151R is 40% larger.
8) woefully lacking and misleading recommendations. Ambient temperature has a big influence and "yellow" on a gauge is meaningless. Revving the engine is NOT the correct process. Get manifold gauges, get a thermometer and add PURE R-134a (no dyes, no oil, no sealant, no additives) to the appropriate high and low pressure values for your ambient temperature using readily available internet resources.

The Stock 09-11 battery pack had a horrifying design flaw resulting in a failure rate of 30% in 3-4 years. The aftermarket batteries do not suffer from this problem.

Complete EGR port clogging results in a faint "pinging" when under light acceleration when all four ports are plugged.

https://www.greenhybrid.com/forums/f...g-howto-30730/

 

Thanks for the info! I know you post a lot here and have worked with these vehicles quite a bit, so I definitely take this advice to heart.

Regarding the A/C system, when I take it in to have that high-side hose replaced, I'm assuming they must evacuate the system prior to removing it. So, I will be to sure to request a proper recharge with addition of the recommended amount of oil. (I know the oil is special low-conductivity SE-10Y. Some comes out with a vacuum, but likely not 100%. On the other hand, some has already come out as this is what makes the leak visibly obvious. I would hate for some random shop to not realize the high voltage electric compressor requires this oil!)

Glad to hear about the new high voltage battery. I'm really loving my Bumblebee so far. Took longer than usual to receive due to supply chain issues, but the install was honestly really simple. To anyone else, watch out for the sharp metal shielding! Gloves are necessary for this, and of course the high voltages. Always confirm with a tested multimeter before touching things.

For the time being, my (obviously far from ideal and very inexact) A/C recharge seems to be working great. It's one of those things, where the car is worth so little at this point, and I was so used to no A/C for a couple years, that I accept a certain level of risk of serious damage to the A/C system. (At idle, the low-side pressure remains in the middle of the 'green' range with the compressor on. As I rev from idle to around 2500 RPM, this pressure goes down linearly with the increase, stopping right before it hits the white 'low' part of the cheap gauge. Much above 2500 RPM, the compressor clutch disengages to preserve acceleration power. According to this site https://rechargeac.com/how-to/ac-system-pressure-chart, at least my low side pressure is in range given the temperatures I tested at.

I will listen closer for any pinging at light throttle, although I can't remember hearing any yet. For fun, maybe I'll go ahead and take a look inside to see how crammed with carbon it really is. I will say, at certain times I drive akin to a https://en.wikipedia.org/wiki/Italian_tuneup, and I like to think this procedure has minimized my carbon buildup. (In general I drive the car nicely, but there is a mountain I climb very occasionally which requires near-100% throttle for up to 5 minutes.)

 

Personally, I'd continue adding R-134a as needed using a process that works for you and never mess with replacing the hose. 80% of the vehicles I've owned have had very slight A/C leaks that required topping off 1-2 times per year with 1/4 to 1/3 of a $4.88 can of Walmart SuperTech R-134a.

I am the epitome of the Italian Tuneup. Every stop light, every on-ramp, etc., results in an Italian tune up. But as that article states, fuel injection and electronic ignition have made it obsolete. The carbon build-up referenced resulted from the much less exact fuel delivery method of carburetors. Not so with the aggressively monitored and controlled fuel/air ratio.The carbon build up you are experiencing via the EGR circuit is independent of driving style.

 

Just an update on fixing my A/C system - it turned out that the leak was visually obvious. It was coming from the "Refrigerant Discharge Line Hose Assembly", which is what carries liquid refrigerant from the high-side discharge port of the belt-driven compressor to the condenser on the front of the vehicle. I would have left it alone, had the leaks been super slow. However, I found that refrigerant pressures dropped below acceptable within a couple weeks! In my case, it was very clear that both crimped ends of the hose were leaking, as some of the oil could be seen wetting the ends. (Note that the actual seals seemed fine - no leaking there. It was at the crimp points!)


Replacing this part was rather easy, requiring at least partial removal of the front bumper cover. Then it's just two bolts and one bracket. I'd theorize this part might be a common failure point for this vehicle's A/C system, since it is exposed to constant tension and vibration by virtue of connecting the compressor (mounted on the engine) to the condenser (mounted on the frame). The length is also rather short, and the routing requires a rather tight curve of the hose.

For others working through this, know that you can borrow (for free!) a gauge set and vacuum pump from Advanced Auto Parts! The vacuum and recharge process was very smooth. I confirmed the system held a vacuum, then refilled with approximately the right mass of refrigerant. I dialed it in further using the low and high side pressure readings. My A/C is now immediately and ridiculously COLD.

One final thing to note: If you're experiencing A/C issues, it may be contributing to a loss of MPG! Before I fixed this, my engine rarely auto-stopped, and I'd assume the compressor was running far more often in a vain attempt to satisfy the extreme cooling call from the cabin. Now, after the fix, my engine always auto-stops, unless I've just started driving and the cabin is still very hot. It is audibly obvious that the electric compressor is being used far more often after the extreme cooling is taken care of by the belt-driven compressor. This, in concert with the HV battery replacement I recently completed, means my MPG's have returned to their optimal range.

(Thanks again for all the wisdom and encouragement from the forum. I'm enjoying my car more than ever before now. At 163k miles, I think I have a long ways to go!)

 

Unfortunately, the convenience you perceived has turned out to be a negative. Use of the vacuum pump is fine as recovery equipment is used on both types, but for hoses/manifold gauges used on non-hybrid vehicles, you've certainly contaminated the system with other people's oil. When working on electric hybrid compressors, you need to use dedicated equipment. I have two sets of manifold gauges for that purpose.

I recommend an immediate evac and recharge using uncontaminated equipment. Your borrowed gauges likely had contamination with PAG compressor oil residue coating every surface. Very small amounts of PAG oil in the system may increase the conductivity notably. Here's what the manual says about adding the wrong oil:


In the case of use with contaminated equipment, the hope is that the amount added was so little that an evac and recharge will suffice rather than changing out the entire system.

 

Oh yes - I did notice a bit of oil on the gauges I borrowed. Since I had already purchased one of those little hose + gauge kits with the adapter for new (pure) R-134a cans, I used that to add refrigerant, then switched back to the borrowed gauges to confirm low and high-side pressures. Far from ideal, but it seems to have turned out alright. I guess I'll truly know after a few months of usage. I wouldn't recommend anyone do what I did because I was just winging it... I'm accepting a definite risk of damage in exchange for minimal cost.

In terms of other improvements, I may upload some audio of driving at light throttle to determine whether the EGR port 'pinging' is audible. Now that you mentioned that, I may be hearing it. If I am hearing it, it is only slightly noticeable when driving through parking lots. Basically, when I'm at throttle just above idle, typically when between say 1 to 10 MPH.

 

IMHO, you should check with the dealership to see what an evac/recharge would cost. $200 spent now could avoid future headaches. I've replaced an '06 HCH compressor, and I wouldn't choose to take the risk.

My 220K HCH had completely plugged ports and pinged as you describe. My 165k HCH didn't ping, but its EGR ports were closing up with the entire area as filthy as the 220K car. It's an hour job with a few tools and an air hose. Worth doing on higher mileage cars.

 

Good and interesting thread. My car's at 171k miles now and running beautifully. A couple things I found on my car over the years ...

1) The engine mounts wear out but are easy (and not too expensive) to replace. There's a dogbone (aka torque strut) under the engine that you'll want to change at the same time.
2) On my car the belt tensioner bearing wore out and got pretty noisy and then the water pump bearing went wobbly shortly after that. Again, not too hard or expensive and the change in smoothness is very satisfying.
3) On any high-mileage car look at your ball joint and CV joint boots. Miraculously, all four of my CV boots are tight and dry after 15+ years, but I did find tears in the ball joint boots and replaced them. Again, pretty easy and inexpensive.
4) I did the EGR port cleaning and it wasn't too dirty in there but I can see where the openings could clog with carbon, so very worthwhile to spend a couple hours in there
5) My driver's door power lock motor pooped out. It's a pretty fiddly thing to replace, hard to reach and get a little rod back into it's hole, so hope you don't have that job to do anytime soon.

Finally, knock on wood, my current hybrid battery is still alive and kicking. Last replacement was spring of '14, so it's doing much better than the first two. I now always leave my car windows open in the summer to try to lower the temperature inside the car. I strongly suspect that our summer heat in Texas is a big factor in the battery life.

 

I went ahead and cleaned the EGR ports. Thanks for the great guide - this was a very simple job! I used a vacuum to suck the carbon deposits away while scraping them out. The gasket and port cover got a good cleaning as well. It's hard to easily notice an improvement, but I only did a short drive around the neighborhood to test. The 4 ports were not 100% clogged to begin with, but some were certainly mostly clogged. Any thoughts on cleaning the EGR valve itself as well?



After cleaning: