Was it the ethanol mix fuel or an oil change gone bad?

Question

We own a 2004 Mercury Monterey and up until now have not had any serious issues with it. We got gas from Sam's Club on Wednesday and Friday and their gas is 10% ethanol which our van is not used to. We also got our oil and our air filter changed on Wednesday as well.

Yesterday our check engine/ emissions light came on, so we went through the troubleshooting list in our manual. We added dry gas, checked the gas cap, made sure the filter was installed properly. The check engine light is still on, and the manual says if the problem has been resolved it should shut off after three cold start cycles running the van.

What I am wondering is, is there a possibility that the ethanol mix could affect our vehicle or could it have something to do with the oil change?

Anyone ever had this happen or have knowledge of what this might be?

Answer 1

If, after doing an oil change, the oil filter was not pre-filled, the oil pressure sensor may not have sensed proper oil pressure within the alloted time frame at startup.

You may want to simply disconnect the negative battery terminal for a couple minutes to reset the computer.

If the light does come back on, have it tested for codes.

Answer 2

All standard gasoline should include up to 10% ethanol. Ethanol, when added to a gasoline mixture, increases the octane number, which is commonly 87, 89, 91 on the American scale (R+M / 2).

All engines built after the 1970s can use gasoline with a ethanol contration up to 10%. A flex-fuel vechicle, however, can use fuel up to 85% ethanol, although it is unlikely that a 2004 Mercury Monterey has a flex-fuel engine.

Ethanol increases the octane number, and reduces the likelihood of early combustion ("engine knock"), and also allows the gasoline to burn cleaner -- better for your engine and better for the environment.

Although a check engine light could indicate possibly anything, in your situation, it's most likely something to do with the oil change. Have your mechanic who did the oil change do a check. It could be a resealing mistake, or more likely that your car uses a specific type of oil that the mechanic did not know of. Some cars, especially high-end cars, use unique engine oil.

Answer 3

My guess is that you're losing oil pressure due to a bad seal when they installed your filter or oil drain plug. Maybe a defective oil filter or installing the wrong one because the correct one was out of stock is causing a restricted flow... I would get this figured out before driving any more. Driving the vehicle when there's the slightest chance oil may not be flowing properly is madness.

It could just be bad fuel... But I wouldn't take any chances at all considering an oil change was just done. A dealer could pretty easily hook into the computer and see exactly what problem the "check engine" light is indicating.

They might have accidentally disconnected an electrical connector somewhere. Or disconnected one for better access and forgot to reconnect it... Disconnecting the battery for awhile and resetting the computer sounds like it might be worth a shot. Possibly was a temporary situation that won't clear until the computer is reset. Nothing to lose in trying it...

Answer 4

Ethanol enhanced fuel is not a problem in Fords.I use it all the time.If you checked the oil level and it was normal,that won't be it either.The check engine lite comes on when the computer senses a problem in the engine control systems.If it comes on and stays on you have a "hard" code set.The manual should have explained this.If it had come on and then gone back out it would have been a "soft" code.You can take it to Auto Zone and they will tell you what the code is,and which system is affected.But before you "throw parts at it" hoping to fix it ,I would suggest finding a reputable shop to diagnose said system,fix it right the first time and get a guarantee on the repairs.

Answer 5

yes it the enthanol mix, if ur car is not compatible dont use it.