Engine falters under 60F

[tcman54]

I have a 2016 Ecoboost Stang that for the most part still runs like a champ except it seems that under 60F outside the engine chugs, sputters, pings, aka just isn't quite as responsive.

During spring, summer and fall here in NE Florida when it is in the high 70's, 80's and 90's the engine is fine.

What can be causing this, would premium gas help, do I need a tune up, better oil?, any help would be greatly appreciated.

Thanks
Terry

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[sk47]

Hello; Some things come to mind. One old school thought would be the thermostat could be stuck in the open position which would not allow the engine temp to get up to normal. Seat of the pants check could be the heater output.
Much more likely would be one of the sensors found around the engine. Not sure where and how many there may be. At least one sensor for the coolant temp. maybe one for the oil temp. Maybe one for the air intake temp. Could be duplicates of such sensors. Also might be a secondary effect from a sensor such as the mass airflow sensor. These sensors should show up on an OBDII scanner.

Keep in mind it can be wiring harness problems causing the sensors to have false readings. Some makes used a soy based plastic insulation in place of the crude based. Rodents like to chew on it. If the car was ever flooded the moisture trapped inside of the connectors can lead to corrosion.

Mostly I am guessing and may not be anywhere close

 

[tcman54]

Sorry, to be more specific, it only happens under acceleration.

 

[Mach VII]

No check engine light when this happens? I would think that behavior would throw a code or two...

 

[tcman54]

No lights come on, maybe bad gas?, I went back to buying the cheap stuff at Race Trac stations but that was a long time ago.

Terry

 

[sk47]

Hello; How many miles on the car? Again my comments are just guesses. If a lot of miles it could be something such as partly clogged injectors. Maybe spark plugs.
Number one WAG is a carbon build up on the valves, spark plugs or just inside the cylinders. The newer engines are often direct injection.
In the older port injection fuel had to come into the cylinder around the intake valve so the fuel would keep the intake valves cleaned. A carbon build up can cause pinging (pre-ignition/detonation). The carbon deposits can hold enough heat to ignite the fuel mix under compression (diesel effect) before the spark plug sparks.
Two ways to maybe check. Pull the plugs and have a look or stick a camera into the spark plug hole. If carbon is found the internals will need to be de-carboned. There are DIY ways to do this if you are inclined and there are shops who do this. A much more common thing with the direct injection engines.
In the old carb days I would run an engine slightly above a fast idle and drip very small amounts of water into the carb. A risky thing to do but it worked. The idea was when water turns to steam it's volume increases something like 1700 times. This would knock out some of the carbon. I also would run hard in the rain thinking the moisture saturated air would help clean out an engine. However neither of these will work on a bad build up.
( Note- if you do have carbon it might be worth adding an oil catch can. )

My second WAG is the turbo system. maybe a pop off valve or some such. Maybe a poor seal in the various pipes and fittings.

 

[tcman54]

43000 miles in exactly 5 years, car has never been driven very hard, garage keep, routine oil changes, tire rotation, etc.

 

[sk47]

43000 miles in exactly 5 years, car has never been driven very hard, garage keep, routine oil changes, tire rotation, etc.

Hello; Not excessive mileage but enough to get some build up. Some simple things to try may be to add some sort of fuel injection cleaner to the fuel. Chevron techron is some I have used. There are others I have used as well. There are also some such a Gumout which can be added to the oil as well as the fuel. My suggestion is to do some checking with someone you trust about which brand to use. Some of your issue may well be partially gummed up injectors.
I have not yet owned a direct injection engine so cannot say from personal experience. Have read about the fuel injection system. Maybe do a web search about direct fuel injection and about the oil catch can.

A catch can is an add on device to the intake system. Todays cars do not allow the internal vapors out into the atmosphere like in the old days. Blowby which get past the rings, oil vapors from the crank case and such get plumbed back into the intake system to be burned in the combustion chambers. Those vapors over time can gum up the inside of the intake runners and especially the throttle body. An oil catch can will trap some or much of this oily vapor before it gets back into the intake.

Before I forget. Maybe run it a bit hard in the rain. Just do not wreck it.

 

[tcman54]

I do have a catch can installed but anyways thanks for all the suggestions.

Terry

 

[ice445]

I'd verify MAP sensor accuracy as well as log what the PCM thinks the outside temp is (it will always read a little higher than ambient, that's normal).

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