dalrex

I have a 99 c230k. My gas tank is about 1/4 full and I can only put in about $2.00 and it starts to overfill. My gas gauge is correct, I have already verified that. I have three mechanics opinions:
1. replace the gas tanks, because it is something inside the tank that you can't replace.
2. check the flap at the bottom of the filler neck, it could be sticking.
3. some type of evaporator module under the hood might need replacing.

Here is what happens...When I remove the gas cap, I hear some sort of air sound and then a thunk, which leads me to believe that it is closing the flap at the end of the filler neck. After $2 or so, The gas will still go down, but VERY slowly.

Does anyone know about a problem like this or maybe even have some diagrams for the gas tankand filler neck, or maybe a location of this evaporator module??

Dale

sosh

This is not normal for pressure to build to the extent that you hear a hiss when taking the cap off. The most likely problem is the vent to the charcoal cannister is malfunctioning. For this problem I would go to your dealer not a independant mechanic. Repair could be warrantied

dalrex

I've got the car booked in for Tuesday, I will let you know what happens. Thanks for the reply.

Dale

s810

Have you changed elevation dramatically? I drove from Denver to Albuquerque once and couldn't get more than 25 cents worth of gas in the tank before the pump shut down. Another customer said difference in air pressure between the gas tank and the outside air caused by the drop in elevation was causing my problem. I don't know if he was right but after letting the car set overnight in Albuquerque, I could fill up with no problem.

dalrex

Unfortunately, I haven't been travelling anywhere. The car hasn't left the city for a while. So That probably isn't it. But I will keep that in mind if we go anywhere.

Thanks,
Dale

phungpho

I have a 2000 E430. My gas tank is about 1/2 full and I can only put in about $10.00 and it starts to overfill. My gas gauge now shows 3/4 full. I don't know if the gas gauge is not correct or I have a similar problem with the Gas tank. So far, I have tried at different gas stations. The funny thing is at Shell, I could fill up and the gas gauge shows 'Full'. Any other stations, so far, I can fill up up to 3/4. The last couple weeks, the Shell station was closed for a maintenance, so I couldn't go back and check it out. I also heard that a lot of people also has the similar problem with the Gas sensor.

mbtech208

The problem your car has is a bad fuel-level sensor, a very common problem in many MB models, including yours. Fortunately, your car is about the easiest model of all to change the sensor. It's about a 10 minute job.

phungpho

mbtech208,
Thanks. By the way, does the 'new' Fuel-level sensor last longer? Once we replace it with the new version, hopefully it won't happen again. I heard so may people complaining about this problem. I can not imagine that Mercedes doesn't know how to make a 'good' Fuel-level sensor.

dalrex

The dealership says that the expansion reservoir is plugged and there is no way to unplug. So I have to buy a new one for $291 plus labour. On a side note, my blower motor is not working properly and they say that I need a new one ($454 plus labour). I have 84,000 km (52,000 miles) on my 1999 mercedes... shouldn't these things last a little longer than that?! My warranty was over at 80,000 km, how convenient for them... Can I get Mercedes to pay for some of this??

Dale

mbtech208

Mercedes won't pay for it, because its out of warranty obviously. However, you're a good customer (you bought the car from that dealer, you don't complain a lot, you always take the car to that dealer for service, you give good marks on surveys), most of the time the dealer will pay for at least half of the repair price, if not all of it. Basically, if they like you, they'll help you out.

dalrex

Finally got the problem fixed. It was a carbon filter in the DRIVERS side rear, not to be mistaken with the expansion tank beside the filler neck (which they replaced first and didn't fix the problem). Also costed about twice as much too! Total with labour costed around $800... but now I can put gas in!

Thanks for your feedback,
Dale