Mustang Parts
   Carrying Saleen wheels and Bullitt wheels.

Sunday, August 28, 2005

My PermaCap Failure

I bought this gadget for my car some time ago, the PermaCap, which is a replacement for your gas gap. The selling point of the PermaCap is that you don't have to unscrew your gas cap to refuel--you just shove the pump nozzle through the spring loaded door, and pump away.

While it worked, it was great. After several months of use, the PermaCap caused my car to set an evaporative emissions DTC, and turned on my "Check Engine" light. After replacing the PermaCap with my stock gas gap, my code went away and did not return.


Permacap detail, showing the grungy flat rubber sealing ring on the fuel cap door

I suspect that what happened is that the rubber sealing ring on the cap door picked up some grime, which caused a microscopic leak. Today's OBD-II diagnostic systems are required to detect a 0.020" leak in your fuel system. Most of them use a pressure leak-down or bleed-up method: they apply a vacuum to the fuel tank by pumping the fuel vapor out, either with manifold vacuum or an electric pump; or they apply positive pressure with an electric pump.

Kleen Wheels Corp, the maker of the PermaCap, claims a lifetime warranty, so I will see if I can send the cap back for a replacement, and perhaps they will have some advice on how to avoid "Check Engine" lights in the future. I suspect they will tell me that I need to remove and clean the PermaCap once in a while--which would negate most of the value of having such a device to begin with.

I also see that on their web site, they are selling a "new and improved" PermaCap II--so maybe they fixed it?


Anonymous said...

What is their website address ?

Scott said...

And the big deal about the idiot light being on?

There's a cure for that: Tape.

Or, as a new car dealer told me when I first openend my lot: "We take the bulb out, examine it and then we place it on a flat surface...and smack it with a hammer."

I asked "You do that to all your used cars?"

They replied "Used? Hell, we do that to the new ones..."

Y'all get too excited about idiot lights and stupid government regulations.

The Auto Prophet said...

Um, that "idiot light" may be telling you that your knock sensor is hosed--ignore that, and you may need a new engine.

Or it may be telling you that your 02 sensor is hosed--and you may be dumping 10% too much fuel down the pipe, wasting money.

If I key-on a car, and the MIL doesn't light up (key on self test), I won't buy the car. Period.

Scott said...

You're one of those.

I am certified, since I was 19. Been servicing independently since 21. Been dealing since '94. Own a million+ annual dealership, pretty good for this little town.

The fact is, over 80% of cars and trucks over 8 years old have the idiot light on. 70% of the time it means little or nothing when it is on in newer cars.

If you are buying a car you should have it diagnostic tested before you buy it. That's what a responsible person does, not rely on the idiot light(or lack of it)or the salesgeek. If you have owned the car for a while you should notice the decrease in fuel economy(it can be far, far, far more than 10%), or the rattle, or the pulse, etc independently of the light(if it fails you'll just keep dirving cause "hey, it must all be ok the light's not on"?).

Point remains, you are far too concerned with the light. Apparently even moreso than I thought.

The Auto Prophet said...

I am an engineer on the product development side. I am very familiar with the OBD system and how it works.

Every DTC has a reason, and most of the codes point to a significant hardware failure of some sort--knock sensor, air temp sensor, cylinder head sensor, fuel pressure, etc.

Chances are, if you have a MIL light, your car is running at less than optimum efficiency. Sometimes, you may even be damaging your enginer.

Also, if you ignore the light for a minor code, you may mask a more severe code down the road.

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