97 Z3 owners : Simple request

[Ryan Turner]

I just put this in my other thread, but because of the esoteric title, many may not go in there.

I would appreciate the following:

After you drive the car, please unscrew your gas cap and tell me if the seal on the inside of the cap is wet.

In troubleshooting a potentially very expensive problem, I'd like to know if that is normal. If you wouldnt mind telling me your apx fill level when you check, I would appreciate it.

[Ryan Turner]

This is a picture of the wetness circled in yellow.

[MicksZ3]

Just got home, have 3/4 tank of gas and its dry.

[Ryan Turner]

Many thanks!! If a few more could comment I'll be more certain this is the cause.

[@ bimmer2.8]

[prdz3]

so I brought my other car), but I'm sure I would have noticed if the cap was generally wet. To my knowledge, it's always been dry.
Phil '97 1.9 Montreal Blue

[Ryan Turner]

Thanks!

[XZ-Driver]

I don't have a Z3 any longer since it was crushed by several trees last Feb. I do recall haveing a problem that was related to my gas cap. Once in a while the gas would come out after a fill up. I did not over fill but even after 50 miles I would get the smell of gas and find that it was flowing out of the filler hole even with the cap on. The solution was a new gas cap. I believe the spring in the latching mechanism had failed and did not seal the filler hole properly. Interesting enough I did not get the CE light because I believe that there was still enough pressure to prevent the error. Try a new cap. It was around $21 a few years ago.

[NC02Z3]

Just came back from some grocery shopping this morning. A 10 mile run with 1/2 tank of gas in tank. That area was completely dry afterwards.

[Ryan Turner]

I still would appreciate a couple more reports, but it looks like the gas cap is definitely the culprit. As soon as my car gets out of the body shop (someone hit me), then I'll be headed to the dealer.

[northz]

I don't believe I have any leakage at the cap. But this is a comment about my gas cap. I have '98 2.8 and we are the second owner. The cap on ours looks like it came off a 1950's tractor. I don't know if it is the original but it works. It came with the car when we bought 3 years ago.

[TexZan (Dover, DE)]

I haven't driven it recently enough to check but I'm pretty sure mine's always dry.

[Ryan Turner]

So I purchased a new gas cap at a glorious cost of $114. It looked a little different than my current OEM gas cap, but almost the same. I reset the check engine light, and I have driven 140 miles without it coming back on (thats a record). I am fairly confident at 140 miles, it is out of the inspection mode.

What is really odd is that the cap still leaks gas like crazy. Seal is super wet, and if I just fill up and go up my steep garage, gas quickly gets around the seal and pours into the rubber well beneath the gas cap.

I'm at a loss, but if the check engine light can stay off, thats all I care about (I am in a state with vehicle inspection).

[NC02Z3]

Sorry to hear. I just wanted to pass on that I just came back from grocery shopping a few minutes ago. The tank was FULL and my driveway here in the mountains is extremely STEEP. The cap is dry. I felt inside the overflow area too. Nothing.