1.8T oil overfill? Lost gas mileage! Please help!

I doubt it. Overfilling the oil usually results in foaming of the oil and blown gaskets and seals and should have nothing to do with gas mileage---and these things would not generally occur with just a 1/2 quart of overfill. 2 or 3 quarts overfill----is a problem.

I would suspect something totally different---

|I have searched high and low to find an answer to this question: | |Will overfilling the my oil by .5 quart in my '02 Jetta cause a loss |in gas mileage of >5 MPG?!? | |What would cause this loss in mileage? | |Will the mileage be restored? I have since drained the .5 quart... | |It was driven for approx 800 miles with this extra .5 quart of oil. Is |there any permanent damage?

No damage, I doubt it has anything to do with your fuel economy. Rex in Fort Worth

Where do you live? Here in Colorado we go to oxygenated fuel in the winter time. Typically, that means 10% ethanol blend for the gasoline. My Passat V6 would lose 3-5mpg in the winter and would gain the mileage back when we switched off the oxygenated fuel.

Keith

WI. (I don't think they switch gas on us, but they may! where would I find out?)

More importantly, is the dealership going to point fingers at this when we take it in, voiding the warranty?

I notice no oil leaks, however I think I am going to change it out a little early because the oil smells like gasoline.

Thanks for the answers guys, I appreciate it. Now if I could only track down the REAL problem...:)

any other suggestions or hints appreciated.

Thanks

Look on the pump at the station, here in Maryland they do switch fuels in winter and have to post that they are using Oxignated Fuel. Unless you live on the Eastern shore of Md, they still use the regular stuff year round.

Why would the dealer point fingers, you have done nothing wrong (other than going to the dealer) allthough some are good, I just havn't found many.

If your oil smells like gas you have another problem, perhaps a bad injector or something causing a Rich Air Fuel Mixture where the raw fuel is contaminating your oil, perhaps thats where your extra .5 qt is coming from. Good Luck, Butch

Where do you get your gas?? I live in WI also and have found that if I get gas from a Kwik Trip, my mileage goes down, and I think that they mix with Ethanol all of the time.

Is it possible too much foamy oil vapor has coated the MAP/MAF (?) sensor and it's reading the wrong air to fuel ratio?

I'd check for cleaning the sensor type tips.

otoh, with such a recent car you should be able to have the failure codes (if any) scanned to add more to the puzzle.

hth, TBerk

I actually think oil overfill could cause loss of fuel economy. My girlfriend had her oil changed at wallmart in her 95 camry. I luckly was outside when she started her car to leave and could hear the engin straining to turn over when she cranked the key. I was accross the driveway and knew immediatly something was up with her car just by the sound of the starter straining. If the starter is straining to turn over the car, then there will be more resistance in the engine than normal. BUT half a quart is nothing to worry about. My girlfriends car had over a quart more than required. Drained a quart and half or so and the engine cranked like normal.

Walmart Automotive dept. blows

TBerk,

Thanks for the input. I will check out the MAP/MAF sensor to see if there is any problem.

I'm anxiously awaiting the mileage this week, to see if there has been any positive improvement. At this point, I feel it's a combination of: COLD WEATHER, possible OXIGENATED FUEL, as well as CONTAMINATED ROADS (snow, ice, whatever). Usually get gas at pilot or BP. Always super premium, as the mfg recommends.

Anyone know how to get the failure codes on a 'dub?

Thanks

-John