Hi everyone
I've got a cautionary tale. I have been running my 2014 Merc C300 almost exclusively on E85 for the last 35k miles (every now and then I have to fill up somewhere it's not sold, but at least 90% of fuel is E85). It has about 75k total miles.
Recently the car started misfiring like crazy and the dreaded "check engine" light came on. This was after getting very low on E85, and having to fill up with Premium at a station that did not sell it. The problem was noticeable as the E85 got low, then worse when filled with gas. The dealership took a while to diagnose the problem, but eventually figured out that all of the injectors were clogged with what they described as "gunk". At least two injectors were just burned out, and they ended up replacing all six. A $4,000 job.
This car was sold as being fully flex fuel and you keep your warranty if you run E85 (unlike Midgrade). However they told me they'd only seem this problem once before, also on a relatively high mileage E85 car. I doubt that many Merc owners do high mileages consistently on E85. The mechanic told me "informally" never to touch E85 again although the "official" advice is still that it's OK. Note that the problem took a lot of miles / tanks to appear.
My thought on this is that the quality and age of the E85 may factor into it - the car may run fine on nice fresh ethanol but if it's sitting in the gas station for months, then in my tank, getting occasionally mixed with gas, it may develop some jelly deposits. These then accumulate in the bottom of my tank until the car runs low on fuel, they then get sucked up by the fuel pump and clog the injectors.
Has anyone else had similar problems (or no problems after more miles)?
I've got a cautionary tale. I have been running my 2014 Merc C300 almost exclusively on E85 for the last 35k miles (every now and then I have to fill up somewhere it's not sold, but at least 90% of fuel is E85). It has about 75k total miles.
Recently the car started misfiring like crazy and the dreaded "check engine" light came on. This was after getting very low on E85, and having to fill up with Premium at a station that did not sell it. The problem was noticeable as the E85 got low, then worse when filled with gas. The dealership took a while to diagnose the problem, but eventually figured out that all of the injectors were clogged with what they described as "gunk". At least two injectors were just burned out, and they ended up replacing all six. A $4,000 job.
This car was sold as being fully flex fuel and you keep your warranty if you run E85 (unlike Midgrade). However they told me they'd only seem this problem once before, also on a relatively high mileage E85 car. I doubt that many Merc owners do high mileages consistently on E85. The mechanic told me "informally" never to touch E85 again although the "official" advice is still that it's OK. Note that the problem took a lot of miles / tanks to appear.
My thought on this is that the quality and age of the E85 may factor into it - the car may run fine on nice fresh ethanol but if it's sitting in the gas station for months, then in my tank, getting occasionally mixed with gas, it may develop some jelly deposits. These then accumulate in the bottom of my tank until the car runs low on fuel, they then get sucked up by the fuel pump and clog the injectors.
Has anyone else had similar problems (or no problems after more miles)?
