As you all know I have been getting pretty bad 25 mpg gas mileage even on the interstate when driving like a gma. I even took off my header and all that jazz a long time ago.

Symtoms: I hear a whisping sound roughly during the last 300rpms before the trans shifts gears. It happens everytime it shifts up (havent really noticed it during downshifting but when it downshifts its dropping rpms much faster then when i accelerate) but is more noticeable @ lower speeds b/c less windnoise.

So my thoughts is that the valve cover gasket is leaking (I think it has one lol). It sort of looks like there is black soot where it mates to the block. I dont think it is the spark plugs b/c I have double platnium NGK plugs that are only about 20,000 miles on them.
Think that is a good thought as to the noise and poor mpg? I would like to get this fixed over the 4th of July week. Can I easily do it myself or should I have Midas do it, and any idea of the cost?

 

A leaking valve cover gasket wouldn't cause a loss of mpg with gas or a sound before the trans shifts. It would cause an oil leak. It is really easy to change. You need hondabond or equivalent to seal the gasket in the corners. In the DIY section, Acc 5th gen.... thread has a link to a site with a 5th gen shop manual split into chapters.

If you have oil in the spark plug tubes, get valve cover gasket along with the spark plug tube gaskets. FelPro makes good gaskets IMO. Just pay attention to the way the original spark plug gaskets are installed, because you will be tempted to install the seals upside down.

If the tranny is the source of the noise, then maybe change the fluid with Honda ATF. Do three drain, drive, refill to replace old fluid.

 

yea the only problems a leaking valve cover gasket will cause is oil leaking on something its not supposed to.
valve cover gasket change is easy, just get a new valve cover gasket and some non-hardening gasket sealer/hondabond. take off the upper timing belt cover and take the plug wires out of the head, but leave them plugged into the distributor. Then just take off the valve cover. pull off the old gasket, put the new one in the valve cover (theres a groove for it), and rub a very small amount of gasket sealer on the parts where there is a 90 degree angle. assemble, start it up, and check for leaks.

 

Grrr, it didnt take my reply. Thanks for the help guys! I am going to check the plugs this weekend hopefully.

 

I changed the tranny fluid once about 400 miles ago but the sound was there before. Might be exhaust gasket...AGAIN[:@]

 

Any other ideas as to what the whisping sound is? I have tried getting it on my video camera but it didnt pick it up.

 

Could the MPG be dirtyEGR ports? I only have 98k miles. I tried viewing the EGR diy but it gives me the page not availble. Is there any way to tell whether they are dirty? And do you think I am capable of cleaning them? Wouldnt want to mess anything up....

 

Dirty EGR ports will make your car run better in certain rpm range. Google T2T013.pdf and the last two pages have the instructions for the accord. Also the site I referenced above in the DIY section has directions to clean the EGR ports.

 

What are 18" Turning Blades? If they are larger tires, your speedometer will be in error (going more miles than you actually have covered), and your mileage is worse than you think.

If tires are actually smaller than stock (I've seen some impossibly thin aspect ratios!), this can have a reverse effect, and reduce your mileage artificially.

Stock tire size is only way to have correct speed/mileage indicated.

Do you have a Cold Air Intake? If yes, this might have an affect on mileage; unmetered air or vacuum leak. CAI's also cause a roaring, moaningsound when accelerating, which OEM intake is designed to eliminate.

I would check fuel pressure regulator diaphragm. Sniff vacuum reference line for gas leak by a ruptured diaphragm. This can really kill gas mileage.

Check fuel injector orings for leaks. Again nose is best tool as leaks can be difficult to spot since evaporation of leaking gas is very rapid. Check all fuel connections for small leaks. Check fuel tank for wet spot due to crack.

Brake drag. Are all caliper pins lubed allowing brake pads to fully release when brake pressure is released? Even slight drag could affect gas mileage, and pad life. Performance rotors (drilled, slotted, etc) might also cause increased "no-brake applied" drag, but I don't know this to be the case. Note that zero drag is not possible w/ any disc brake arrangement I have seen. I have heard that some caliper assys have brake pad "back-off" mechanisms but haven't seen any w/ them.

good luck

 

I just installed the 18's about 2 weeks ago and the mileage has been horrible before I got them.
Once I get some time I will try to find all the parts you listed and test them out!

I have a sri, but it should increase MPG as long as I am not racing around.