2009 GX High/Low Pressure Fuel Filters

[brianosu]

I just finished my 4th replacement of the low pressure fuel filter(the one by the engine) and 2nd replacement of the high pressure fuel filter(by the tank), and I am convinced that the GX service manual has these replacement intervals backwards. In my opinion, the high pressure filter should be the one that should be replaced every 10K miles, and it that is done, the low pressure filter would probably stay fairly clean for 15-20K+ miles. I just replaced them both after going 12-13K, and the high pressure filter was saturated. The low pressure filter was only slightly dirty - it looked like it could go another 5K easily.

The last time I replaced them both at the same time using the service manual's recommendations, the high pressure filter had been in for 30K and the low pressure had only been in for 10K. The high pressure filter was really saturated and the low pressure filter was also really dirty - it looked like I let it go too long, but it had only been in for 10K.

Has anyone else noticed this when changing their own fuel filters? I'm thinking I might just start replacing both at 15K.

[HRAguy]

Re: 2009 GX High/Low Pressure Fuel Filters

Question.

Are you refuelling at home, or a commercial station (or both) ?
I have heard of a few cases where large quantities of water have been found in the vehicles CNG tank. If the dryer is not working correctly, it could explain why your filters are saturated.

[brianosu]

Re: 2009 GX High/Low Pressure Fuel Filters

I only refuel at commercial stations.

[HRAguy]

Re: 2009 GX High/Low Pressure Fuel Filters

I have not heard of any recent moisture complaints about any ONG stations, but it puzzles me on why your HP filter is "saturated" after just 12K. If the fuels meets the J1616 standard, the filter should be absolutly fine after 12K. Guess that it is possible that one station had a short term maintance problem, and some water found its way into your tank.

[brianosu]

Re: 2009 GX High/Low Pressure Fuel Filters

It looks more like it's oil from the compressors - not water.

[HRAguy]

Re: 2009 GX High/Low Pressure Fuel Filters

If the station does not change it filters, or the wipers rings are badly worn, carryover oil can be dumped into the tank. It could be a long time before your tank cleans itself out. Another reason why oil-less compressors are the way to go.

[freedml]

Re: 2009 GX High/Low Pressure Fuel Filters

I'd change the HP filter often and 'inspect' the LP filter, perhaps alternating two so that one can fully dry out between changes.

[Curtis]

Re: 2009 GX High/Low Pressure Fuel Filters

My understanding is that most, if not all, of the ONG infrastructure is pretty old. I can't speak to their maintenance record, but an old compressor with worn 3rd & 4th stage rings will pass a lot of oil to the dispenser and ultimately to your car. The regular checking/changing of the desicant cartridges is also key if they have "wet gas" and are usinggas directly from the well.

It amy also be a particular site that you are using, as opposed to all of them. This would be difficult, if not impossible to determine from where you sit. If this is going to be an ongoing problem you might consider home refueling. There is still a $2k tax credit for a home unit and they are oil less compressors, so it would eliminate the problem completely unless you are on gas coming from your own well. In that case you may need to add some inline filters to the setup. At 12k filter changes, you would eventually recoop the cost of the HRA and end up coming out ahead. Just something to consider.

[DavidP]

Re: 2009 GX High/Low Pressure Fuel Filters

How difficult is changing the fuel filters? I had the local Honda dealer change one filter at 10K miles - cost $164. Seemed high?? I thought it was the high-pressure fuel filter?? The service writer said the other filter needed to be replaced at 30K miles?? I can't find the service schedule in my GX books. Where in Okla, do you live? We live in Edmond.

[brianosu]

Re: 2009 GX High/Low Pressure Fuel Filters

I fill up the new Oncue station in OKC probably 98% of the time, so I would be surprised if it is caused by lack of maintenance on the compressors. I would think that most people would notice this with their filters if they requested to see them when they have them changed.

DavidP, I thought the cost to have them changed is pretty steep as well...that's why I started changing them myself. You can order the LP filter online for about $52, and the HP filter for about $22. I had my low pressure filter changed at 10K at the Honda dealer as well and asked to see it - it looked brand new after the first 10K. I think the low pressure filter is the more difficult one to change because of where it is and getting the housing back on while keeping the o-ring in the right spot. The high pressure filter is fairly easy to change because it is easy to get to.

[Darkstarchuck]

Re: 2009 GX High/Low Pressure Fuel Filters

I changed both of mine @ 88K miles, after having the car for ~6 months and 9K miles. I assumed that the dealership where I bought my "Honda Certified" '07 Civic would have replaced all replaceable filters, so I was very surprised to find a LP filter with what looked like 88K miles on it. There was about 1 tbs. of compressor gear oil in the bottom and over 3/4 of the filter was wet with the oil. The HP filter was very clean and dry, as was the housing. I'm going to ask the dealership to give me the new LP filter they owed me from the start, but neglected to install. Any other thoughts?

PS I don't have a HRA

[kennyt1123]

Re: 2009 GX High/Low Pressure Fuel Filters

I have a fuel filter question regarding a 2006 Civic GX I bought about 6 months ago. It had 42K miles and the previous owner filled it at home with a Phill unit. I fill almost always at newer stations which I assume have oil-less compressors. I just now got around to changing the filters at 48K, which the previous owner never did. The HP filter had absolutely nothing in it. It was dry and as clean as the new replacement filter so I left it in to save the new one for later. With the HP filter being so clean, do I need to worry about even looking at the LP filter right now? If nothing is getting into the HP can anything somehow get past it and contaminate the LP? The LP seems hard to get to and I don't want to pull it out if I don't have to.

Thanks!

Kenny Thomas
[email protected]

[Darkstarchuck]

Re: 2009 GX High/Low Pressure Fuel Filters

The LP filter is not hard to reach with extensions and a universal on your ratchet.... When the gas "expands" as it decompresses, every thing in the gas does the same thing, so, maybe, there would be oil "condensate" from the gas at the low pressure regulator/filter. My experience is limited as stated above, but you should really check it, if for no other reason, Honda says so. I also would not assume that the newer stations are oil-less...... A better assumption would be that they may possibly have better separators/filters... OK? there's my $ .02.

[cowboy]

Re: 2009 GX High/Low Pressure Fuel Filters

Real compressors have oil. There's too much heat, to many hours running not to. I would not own one that did not have oil. You just have to keep them in good shape and clean the filters.

[freedml]

Re: 2009 GX High/Low Pressure Fuel Filters

Oilless compressors may not be 'real' but I sure like not having to worry about whether there is oil in my CNG. I'm on utility gas in a mild climate, so I don't need to worry about water in there either.