Hi,
I've got a 99.5 Jetta IV (107,000 miles) and had a problem last week and was wondering if anyone had any ideas. I was going uphill in 5th gear with the tank near empty but the reserve light wasn't on yet. It started loosing power and then was fine again, and did this again on the next hill. It acted just like it was running out of gas, so I go fill it up and it only takes 11.5 gallons. I'm pretty sure it will hold up to 14.5 gallons, so I don't think it was out of fuel. Since then I drove 1200 miles back home and didnt' have the problem again (ran fine up and down hills), although I never let it get to where the guage read less than 1/4 tank left since I was kind of worried about running out of fuel.
So the second part of this is that a few weeks ago I hit a large object (an irrigation pipe elbow of all things) in the freeway at 75 mph, which shattered the oil pan and really bonked the bottom of the car good. It hit the bottom of the engine with enough force to pop the windshield washer motor off of the reservour, and it also looks like it put a dent in a fuel tank (near the rear of it) too.
So I guess I could see how the dent in the fuel tank would lower the capacity, but it's not that large of a dent (about 5 or 6" across) to reduce it from 14.5 gallons to 11.5 or 12. And I also wonder that even with reduced capacity, why it would run out of fuel going uphill. but be ok level. I'd had it with less fuel in it (i.e. has taken 12 and 12.5 gallons) prior to this out-of-gas problem (but after striking the object).
So I was wondering how the fuel system handles going up/down hills. Is there a center low spot it in the tank if draws fuel from, or multiple spots? Maybe something got knocked loose in the tank? Maybe this dent is somehow strategically placed so that fuel doesn't move to were it needs to be on uphills.
thanks, Dean.