Changing Fuel Filter

[Batman]

My 2004 Convertible had to sit for 3 years. It was garaged with temperature never going below 40 degrees. Before I tried to start it up, I changed the oil, put a new battery in it and put 10 gallons of Chevron 91 octane gas in the tank. (tank had about 3 gallons of 3 years old gas in it) I also added a gas additive/cleaner in the 10 gallons along with some Techron and she started right up.

I added 7 oz's of Seafoam to the crankcase and drove the car without any problems 200 miles. My plan is to change the oil in another 100 miles or so and change the oil again.

My question is the fuel filter. Should I change it out or should I be ok since its running well? If so, how is this done? My understanding is it is in the fuel tank.

 

[Toms007]

It will be a real PITA to change out the fuel filter, if my understanding is correct (just as you stated, in the tank). Let's wait to hear from the seasoned mechanics here.

:eyerole

 

[dadaroo]

If the injectors like the fuel I would not worry about the fuel filter inside the tank.


Mr. Sam

 

[LLC5]

My 2004 Convertible had to sit for 3 years. It was garaged with temperature never going below 40 degrees. Before I tried to start it up, I changed the oil, put a new battery in it and put 10 gallons of Chevron 91 octane gas in the tank. (tank had about 3 gallons of 3 years old gas in it) I also added a gas additive/cleaner in the 10 gallons along with some Techron and she started right up.

I added 7 oz's of Seafoam to the crankcase and drove the car without any problems 200 miles. My plan is to change the oil in another 100 miles or so and change the oil again.

My question is the fuel filter. Should I change it out or should I be ok since its running well? If so, how is this done? My understanding is it is in the fuel tank.

The fuel filter in your tank is considered a lifetime filter and should only be replaced if a problem occurs. Be careful adding a lot of additives at the same time, sometimes they don't mix well and can create problems. I would get the Seafaom out of your oil soon. Enjoy your ride.

 

[Batman]

The fuel filter in your tank is considered a lifetime filter and should only be replaced if a problem occurs. Be careful adding a lot of additives at the same time, sometimes they don't mix well and can create problems. I would get the Seafaom out of your oil soon. Enjoy your ride.

My thinking was getting the varnish out and off of the fuel filter. After 3 years of sitting, I'm assuming this is the case. Obviously, there is no way to know unless I take the filter out. Not sure how well its going to filter the bad fuel with varnish.

 

[Batman]

...I would get the Seafaom out of your oil soon. Enjoy your ride.

After I drove the car for 200 miles, I looked at the oil and it looked the exact same color as when I put the new oil in. I expected it to be at least a little brown, so was surprised to see that. I guess that is a good problem.

 

[Batman]

If the injectors like the fuel I would not worry about the fuel filter inside the tank.
Mr. Sam

I'm going to say it definitely liked the fuel since it started right up(didn't expect that) and has been running just fine for 200 miles, meaning no back fire, sounds of engine not getting fuel, and engine sounds good. Just worried about how much varnish there could be after three years of sitting without any additives.

 

[Hib Halverson]

The fuel filter is inside the left fuel tank. GM moved the filter there because of the Fed's continuing push to reduce evap emissions.

Because of the high cost of pulling the tank to replace the filter, I wouldn't do anything with the filter unless you document a fuel pressure problem as being caused by a restricted filter.

If you are worried about "varnish", I'd run a couple more bottles of Chevron Techron or, better yet, Red Line Complete Fuel System Cleaner though the engine using one bottle per tankful of fuel.

Also, you mentioned you had mixed a "gas additive/cleaner" with Techron. If you are using Techron, which is a detergent-based fuel system cleaner (as is the aforementioned Red Line product) don't waste money on any of the cheaper solvent-based cleaners because the detergent-based cleaners are much better products and they make any solvent-based fuel system product redundant.

 

[Batman]

...If you are worried about "varnish", I'd run a couple more bottles of Chevron Techron or, better yet, Red Line Complete Fuel System Cleaner though the engine using one bottle per tankful of fuel.

Also, you mentioned you had mixed a "gas additive/cleaner" with Techron. If you are using Techron, which is a detergent-based fuel system cleaner (as is the aforementioned Red Line product) don't waste money on any of the cheaper solvent-based cleaners because the detergent-based cleaners are much better products and they make any solvent-based fuel system product redundant.

Thanks. I will finish off tank of gas I originally put in it and try the Red Line Complete Fuel System Cleaner on the next tank. Sounds like that will clean the varnish away better than the "solvent" based products.

 

[Tuna]

I've been real happy with "BG 44K" fuel system cleaner.
I'm also a fan of Red Line products.

As suggested, check the fuel pressure to make sure there are no restrictions. A partially clogged fuel filter will allow adequate fuel flow at moderate performance levels but will cause the pressure drop at higher RPM. This can cause a lean condition.

Years back, my C4 LT4 Vette had a clogged fuel filter that caused the engine to run lean at high RPM. The old C4 computers and diagnostics did not tell me until it was too late - burned a head gasket.

 

[Batman]

..check the fuel pressure to make sure there are no restrictions. A partially clogged fuel filter will allow adequate fuel flow at moderate performance levels but will cause the pressure drop at higher RPM. This can cause a lean condition.

Years back, my C4 LT4 Vette had a clogged fuel filter that caused the engine to run lean at high RPM. The old C4 computers and diagnostics did not tell me until it was too late - burned a head gasket.

Thanks. How do you check the fuel pressure? Is there an error code that will pop up for low fuel pressure?

 

[Hib Halverson]

Fuel pressure is not monitored by the car's on-board diagnostic system. You have to test fuel pressure with a special pressure gauge which you can buy from a variety of vendors.

The test is run with the key on but the engine off.

You connect the gauge to the fuel system test connection, then turn the key on but do not start the engine. The pump will run a few seconds then shut off. With the pump running, pressure should be 55-62-psi. You may need to sucessively turn the key off and back on to keep the pump running long enough to read the gauge. You also can use a scan tester to command the pump "On".

When the pump stops running, pressure will drop, but it should stay above 51 psi for five minutes or more.

If your fuel system does not operate according to those instructions, if you are a DIY, consult the Service Manual as to repair procedures. if you're not a DIY, take the car to a repair facility to have the fuel system checked out.

 

[Batman]

Fuel pressure is not monitored by the car's on-board diagnostic system. You have to test fuel pressure with a special pressure gauge which you can buy from a variety of vendors...

Thanks for the informative reply. I will buy one and see what comes up. I prefer to work on my own car whenever possible so thanks again