LOW MILEAGE AND LEAK ON HONDA GX-Please Help

[dylan71082]

I have a 2000 Honda Civic GX with 77,000 miles. I bought the car through a private sale over two years ago and never thought twice about these problems until I talked to someone about them recently.

The car gets about 130-150 miles per tank fill and no more. Also, when it is getting low, about 3/4 empty tank, it smells subtly like natural gas.

What are my options in getting this fixed? Would it be under parts warranty from Honda since it is the tank? Is this common?

How can I go about handling this without spending thousands?

Please give me any advice that you have. Thanks.

[Curtis]

Re: LOW MILEAGE AND LEAK ON HONDA GX-Please Help

dylan, research this forum. There have been numerous posts about gas leaks in the older Civics, as well as solutions to the problem. There has been some excellent information posted in the GX forum that should give you an approach to the problem.

To answer your other questions... You didn't mention where you were, mileage on the car, or exact situation in which the smell is most apparent. All of this info is needed to allow anyone to be of assistance.

[dylan71082]

Re: LOW MILEAGE AND LEAK ON HONDA GX-Please Help

no problem. I am in Los Angeles and it is a 2000 Honda Civic GX with 77,000 miles. The smell is most apparent when the tank is 3/4 empty. Thanks.

[John Mitton]

Re: LOW MILEAGE {range} AND LEAK ON HONDA GX-Please Help

One possibility is that your tank is full of oil, displacing the available capacity of the cylinder to hold natural gas. This can happen when an old compressor is blowing oil thru to the natural gas at the station. It might be worth it to have a qualified tech depressurize the system, remove the cylinder and inspect inside. He may end up draining a bunch of crud out of there.

Also, are you always using the 3600 pump handle?

[Jay98]

Re: LOW MILEAGE AND LEAK ON HONDA GX-Please Help

I can also smell gas inside my 98 GX when the fuel level gets low, but not after I fill it. It almost seems like the higher pressure stops a leak in a seal, which then starts to leak again when the pressure is reduced as fuel is used.

How could oil in the tank cause a leak? I recently replaced the fuel filter on my 98 and saw oil in the canister. Is this normal?

[dylan71082]

Re: LOW MILEAGE AND LEAK ON HONDA GX-Please Help

I do always use the 3600 psi. Where would I get the tank drained in Los Angeles? Do you happen to know how much that usually costs? and will that increase mileage and the smell?

Thanks.

[John Mitton]

Service shops

We try to keep the top "sticky" thread up to date in our Service & Conversions Forum. There are some options in the LA basin for you to call:

http://www.cngchat.com/forum/showthread.php?t=27

I'm guessing the better part of a man day to do this for you and they can provide a cylinder inspection while at it (ALWAYS perform this each 36,000 miles or 3 years!). For now have you changed the coalescing fuel filter recently? Was it full of oil (this is your first clue)?

As for leaking, my son also has a 98 GX and I have noticed some slight smell in the cabin after it sits for a while. Someone told me it is due to the mercaptain seeping thru the Type 4 plastic but no gas actually escapes - just the smell. Can anyone verify this?

[dylan71082]

Re: LOW MILEAGE AND LEAK ON HONDA GX-Please Help

This confused me a bit. I am not an expert on my car. I don't think there is oil in the tank though because when I fill it up at the station, the station indicates how many gallons it has filled and there is never a shortage to what I am getting at the pump.

If there was oil in my tank wouldn't it fill up partially? Just a guess.

[Larryect]

Re: LOW MILEAGE AND LEAK ON HONDA GX-Please Help

As for leaking, my son also has a 98 GX and I have noticed some slight smell in the cabin after it sits for a while. Someone told me it is due to the mercaptain seeping thru the Type 4 plastic but no gas actually escapes - just the smell. Can anyone verify this?

I would be interested in this as well. While I don't believe I have a leak on my 2002. After sitting a few days with windows up, it seems to me to have a VERY slight garlic oder.

I don't think there is oil in the tank though because when I fill it up at the station, the station indicates how many gallons it has filled and there is never a shortage to what I am getting at the pump.

This statement confuses me. What do you mean there is not a shortage? It would fill until the tank is as full as the pressure at the pump could fill it. Oil in the tank would take up some space. But, you have not said how much fuel you are getting when going the 140 - 150 miles. BTW, 140 - 150 may not be that bad depending on driving conditions and style. Have you done a mileage calculation at all?

I figure mine at about 29 in my normal mixed commuting driving. It goes down if it all around town with the AC on. About the best I have gotten on a long average was on about a 1200 mile trip doing about 65 most of the time, for about 35 MPG.

The most gas I have gotten at one time is about 5.9 gallons. I have only seen that a couple of times. I try to fill well before the light comes on. Not sure if the light still works.

This being said, I would think a fuel leak that affected mileage would be very serious and noticeable. In other words you may still have a leak if you smell something, regardless of your mileage.

Hope this helps in some way.

[Curtis]

Re: LOW MILEAGE AND LEAK ON HONDA GX-Please Help

Just to clarify, oil in the filters usually indicates that the compressor at the station/s you use to fill your vehicle has a problem with it's rings and is blowing oil into the fuel. That's why we have these filters in place, and the value of changing them regularly if you use public infrastructure.

If you use the same station regularly you might try and let them know what's happening. Oil can foul your injectors and cause several problems that would drive you crazy trying to figure out. Changing filters is cheap insurance.

[dylan71082]

Re: LOW MILEAGE AND LEAK ON HONDA GX-Please Help

Do I have to go to a CNG mechanic to have them changed?

And might that be my solution for both the low mileage and the smell?

[Jay98]

Re: LOW MILEAGE AND LEAK ON HONDA GX-Please Help

The high-pressure filter is not difficult to change. The part number is 16905-S1G-003. See the following thread for links to inexpensive Honda parts on the web http://cngchat.com/forum/showthread.php?t=2408

Just make sure you depressurize the fuel system from the shut off valve to the engine before you begin. Turn the shutoff valve (located from inside the left rear wheel well) to the off position. Then start the engine and let it run until it dies.

It is easier to do this job on a lift, but you can do it with the rear of the car on jack stands if necessary.

You have to first remove the fiberglass cover located in front of the rear axle (about 2ft by 2ft square) to expose the fuel filter housing. It is the nice clean stainless steel cylinder connected to the fuel lines on the left side of the car. First slowly remove the drain plug with a 1/4 hex drive wrench or socket. Any remaining pressure will be released from the fuel system at this point, so go slowly. If you have oil in the system, it will drain out of the housing.

You can then remove the housing and expose the filter element. Remove the old element and clean out the housing. Install the new element. Install the new o-ring for the housing and the new o-ring for the drain plug and lightly lubricate them with PAG oil (or similar). Reinstall the housing and the plug. You should check the shop manual for torque specs.

Turn the shutoff valve back to the run position and inspect for leaks. If you don't have any leaks, you're almost done. Reinstall the fiberglass cover and your done.