Photomania

It's absolutely baffling. Every time I wash my 1990 coupe, water gets in the gas tank, and within 25 to 40 miles, the engine stalls out or almost stalls out. Embarrassed, I'll pull off the road and dump a bottle of Valvoline Water Remover into the gas tank, and a few miles later, the problem will clear up.

But this can happen at the worst time: at a toll plaza or at a traffic light.

I"ve removed the panel that surrounds the gas tank nozzle and checked the vapor hoses for leaks. Everything looks fine. I replaced the gas cap with a locking gas cap from Zip Corvette. But still, the problem persists. The drain hose next to the gas cap drains well.

Any ideas. Please help. It's not good for a Corvette to be stranded on the side of the road. This problem started when cold weather arrived. I keep the gas tank full as much as possible. I don't think it's condensation because the problem occurs only when I wash the car. I don't have a garage, but I keep the car under a nice car cover on the east side of my house. Any advice would be fabulous. Thanks. -- Eric

flylowguy

if the hoses and rubber catch basin are good and the drain works, I doubt the problem is there. maybe something else that could be possibly connected to water.
But if the problem comes at 30-40 miles after the wash, it could be a lot of things.
take out the parts and rubber around the tank fill neck and check them again. if no gas odor and nothing looks wrong, I would begin looking elsewhere.

c4cruiser

Have you pumped fuel from the tank to see if there really is water in there? You can remove the filler housing and the fuel pump to get a good view into the tank. Check around the areas where everything seats to the tanks for signs of a seal failure.

Have you replaced your fuel filter? Stumbling and poor throttle response is an indication of a clogged filter.

Bluewasp

when you take off the gas cap is the filler rusted? A friend had a problem with water going into the tank and the area was all rusted out, under the gas cap.

want2drivemy85

you may need a new gasket at the filler neck area, or the bolts may be loose allowing water to enter the tank.

SilverBeast

. That's what I'd check first. The gasket may have a leak or be kinked.

SupaVette

Yeah, i also think maybe the gasket under the filler neck is at fault

Photomania

I removed the rubber fuel filler neck housing from the gas tank. Is this the gasket that you guys are talking about, or is there yet another gasket closer to the actual tank.

I can see that my car's filler neck housing could potentially allow some water to drip down the outside of the filler neck. But if that happens, how would water get into the tank? I don't smell any gasoline when I'm back there checking the components of the gas tank.

I replaced the fuel filter back when this problem first started a few months ago. The Valvoline Water Remover corrects the problem every time. Since Valvoline corrects the problem, can we assume that water is in the tank?

I appreciate your advice, and look forward to any other suggestions or advice you might have. -- Eric

fsr402

I'm going with the bad seal under the fill neck. You will need to get a new seal and new o-rings for the bolts. It's not ahrd job and does not cost much. There are some 10mm bolts holding down the fill tube ( that's also where your pump is mounted to) remove the wires and hoses then unbolt the filler neck and remove the replace the seal and the 0-rings on the bolts and put her back together. That should fix the problem. But when it's apart look every thing over well to see if something is rusted out.

flylowguy

When it's hot outside does air rush out of the tank when you take the cap off? Because if it does, I think that pretty well eliminates the supposition that it might be leaking and allowing water in. Air under pressure can get out a whole lot easier than water under no pressure can get in. Plus if you have no gas odor around the filler neck, that says the same thing.

MikeC4

Eric- Dude, you must have a gremlin in your Vette, plain and simple! Or perhaps it needs an Excorsism!!
j/k of course

After you wash the car, open your hood and make sure that you do not have a water path to your intake. Water could concievably collect in injector well on the intake and get sucked in through a week or worn rubber O-ring. That little rubber compression O-ring on the bottom of your injector is the only thing to keep out water and and other debris from getting sucked in.

Juat make sure no water has found its way into your engine bay....

Just a wild azz guess, but if your gas tank is solid, where else could H2O enter your system....

65Z01

I would put a layer of silicone grease on that rectangular gasket between the mounting flange and the tank and pick up 9 O-rings at Lowe's for those little mounting bolts.

Unless the neck is dented at the cap end that should take care of any leaks, providing there is not any rusted out spots.

Indeed if you hear a gush of air when you loosen the cap the tank is water tight.

BLK/BLK'93

Are you sure it is water in the gas? Today's gas will mix with water. You could add a few cups of water to 10 gallons and not see a problem. My guess is that you are getting something else wet.

Joe C

am i missing something here? i thought the gas cap was non-vented (part of the emissions system). can water get into the tank, through the cap or under the cap? could be something else - ??? just my 2 cents

aboatguy

What happens when you drive in the rain?

Mike

Photomania

I appreciate all the great ideas. I'll pursue these. This website is the best website on the entire Internet as far as I'm concerned.

I'll check under the hood after the next wash to see if water has pocketed near the injectors. I don't drive this car in the rain, but it's not garage-kept. It stays under a car cover during the rain or snow.

I don't notice any smell of gas around the tank. I'm not sure if I've heard any sounds of rushing air when I open the tank. I'll have to listen for that.
I'm thinking that I haven't heard that sound on the Corvette, but I have heard it on my Nissan pickup truck.

It's strange that I bought the car a year ago this month, and this problem started occurring only when the weather turned cold. I haven't washed it in nearly two weeks, and it has been running beautifully. But if I go out there tomorrow and wash it, the engine will stall out after 20 or 30 miles and continue that horrible thing until I give it Valvoline.

Thanks for all the help, guys. -- Eric

87SAM

Try using a garden hose and just hose down a section at a time between road tests Hey, desperate times call for desperate measures!