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Roger Beaudin

Roger ... 10/25/2016

2007 Mercury Monterey Luxury 6 Cyl 4.20L


the enigne is misfiring we thought we had moisture in the gas what else could it be?

We stopped at a gas station and filled up soon after leaving the station the car started to misfire badly. Brought car to our mechanic we added fuel additive for moisture and replaced the fuel filter. It is a little better but still misfires badly what else could it be or could it be a combination of something else?

1 Answer

Teddy B

Teddy B 10/25/2016

All Vehicle Manufactures specifically tell you to add nothing to any
vehicle systems & have done so for 70 years

Any professional repair shop knows that adding something to the fuel tank
will do absolutely nothing

Your fuel already contains 8% Ethanol for the last 30 plus years,so adding another
8 to 16 oz won't do a thing--common sense

The Ethanol in the fuel already is what attracts the moisture to begin with & you
want to add more !

You have a cylinder misfire,that is very common on all vehicles & can happen twice
a year as long as you own it,so why are the shops your going to not diagnosing the
misfires to find the cause

If you don't change spark plugs every 3 years or go more than 35 to 50,000 miles
your going to have problems
Ignition coils & modules fail by the millions every day of the year

You don't keep driving or you will ruin the Exhaust Converter & possibly other engine

The fuel filter is Preventative Maintenance-there you should know how long it has
been since it was changed. They last for many years 5 or 6 with no issues

The shop can see fuel pressure on scan tool data, so why change a filter & do
nothing else & send you on your way,they didn't address your complaint

I change mine every 3 years along with cabin & air filter,spark plugs & other items
Most folks do nothing

Think you need a different shop,it's not better,they apparently failed to do much or
you never asked what was done,you still have a problem

I don't need to explain what a shop would do, as far as road testing & looking at scan tool
data & pulling a couple spark plugs & the required testing to find All Vehicle issues,not
just a misfire.
Find a different shop,go for a road test with you driving & the mechanic
along,get everything you what tested (only) in writing & then return to see the test results

You Authorize nothing over the phone,believe nothing,educate yourself at the shop in
person & see the test results & never pay for the work & leave without the final road
test to confirm a fix & that has to be at least 20 miles,look at Mode $06 Scan Tool Data
before you pay also.You want to see all 8 Emission Monitors run clear or they fixed nothing,
road tested nothing- see the monitors ran & confirm no misfires,proper fuel control,etc

Then you know you can pass inspection & not ruin the exhaust converter

You must use the correct grade of fuel that is in your owners manual & sometimes
a sticker on the fuel door


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