OK...I have an 88 S4...I think she's running rich...but is running really good...the oil is getting dark but you can still see through it on the dipstick...seems to even have more power, and the oil also has a strong gas smell too,,,along with a gas smell while running (but no leaks)...she also will backfire a little on deceleration....any ideas?
That little adjustment for R / L on the strut tower is rusted and cant turn it to make it leaner...perhaps should replace that to adjust, eh?
Thanks for your input....

 

gas in the oil is pretty common so you shouldn't have to worry about it. I have a strong smell of gas in my oil and most every one else does to. I believe the side seals (if I"m wrong somene will correct me) tend to get old and leak causing this issue. As far as running to rich, are you stock? If so it runs rich from the factory and you shouldn't have to worry about it. Believe me if this is your only problems with the car, leave it alone As far as back firing on deceleration it is more than likely your bac vavle I believe, make sure it is clean. I'm not to sure on that one because all my emmisions are gone but if you search for that I'm sure plenty of reading material will come up. Good luck!

 

Fuel dilution can be a serious problem because it negates the lubrication qualities of your oil. Unfortunately, the smell test isn't very accurate (unless the oil is very contaminated). Your best bet is to pull an oil sample and send it to an oil analysis lab.

Blackstone laboratories is the oil lab I use and they will give you a full run down on the oil to include wear metals, additive package levels, TBN, viscosity, any levels of antifreeze in oil etc..

Excessive fuel dilution will result in premature engine wear and should be of concern.

 

Oh, I'm currently on my 4th FC. I bought my first FC new in 1986 and my currently own a low mileage 91 Vert. I've done hundreds of oil changes on FC's and NEVER have smelled fuel in my oil.

 

if you look about a month or so back there is a thread with I can't even tell you how many people have this same issue and their cars as well as mine are fine! Someone else will chime in soon and concur with me I'm sure. To much would be bad yes but most fc's have the issue of "gas smelling oil".

 

Just because a bunch of people experience this doesn't mean it is acceptable. These cars we are driving are old and I suspect that the fuel dilution problems are caused by leaky fuel injectors.

You can be bliss in your ignorance but hey, its your car and your money.

 

oh lord, it has nothing to do with leaky injectors as mine are cleaned and serviced as well as many others. It can happen because of differant things like if you flooded your engine recantly or because of side seal's wearing down. If you want to completely rebuild your engine do to this then fine go ahead but everyone else BESIDES you found that not enough gas leaks into the oil to cause any problems. Now if you flooded and this happend after that it is strongly recommended that you change your oil.

 

well, it has not flooded in over two years so it is not that....since the occassional backfire on deceleration and this just started recently...I'm thinking she just started running running richer than usual for some reason....also, I have an exhaust leak at the main exhaust manifold and perhaps this is throwing the sensors off somehow and inreasing fuel input....what do you think?