Rough idle at cold startup

[SeanB]

I have a slightly rough idle at cold startup. It lasts a minute or two. I can feel it through the driver seat. I am old enough and the tach is small enough to be next to useless for this, but there is some needle bounce. It lasts a minute or so. The car is on a new timing chain and phasers as of last week with about 100 miles on them of daily driving and no shenanigans. 2015 sho 80k only 93 brand-name octane with no other issues.

Thoughts?

 

[FiveLeeter918]

are you tuned?

 

[SeanB]

No tune. No performance parts. Bone stock.

 

[AlexS925]

How are the plugs?

 

[SeanB]

How are the plugs?

Unsure. But, the Ford dealer just did the timing belt and phasers a week ago, so wouldn't they have advised me the car was running rough? In any event, good point. Check the plugs.

 

[shogen4]

I have a slightly rough idle at cold startup. It lasts a minute or two. I can feel it through the driver seat. I am old enough and the tach is small enough to be next to useless for this, but there is some needle bounce. It lasts a minute or so. The car is on a new timing chain and phasers as of last week with about 100 miles on them of daily driving and no shenanigans. 2015 sho 80k only 93 brand-name octane with no other issues.

Thoughts?

I have the same issue in my 2013 SHO with 89,000 miles. Its been there forever I think. Not sure why.

Here is my latest post:

I have a slightly rough idle at cold startup. It lasts a minute or two. I can feel it through the driver seat. I am old enough and the tach is small enough to be next to useless for this, but there is some needle bounce. It lasts a minute or so. The car is on a new timing chain and phasers as of last week with about 100 miles on them of daily driving and no shenanigans. 2015 sho 80k only 93 brand-name octane with no other issues.

Thoughts?

I have the same issue in my 2013 SHO forever I think. Here is my latest post.

Hi, this is Shogen4. My 2013 SHO has developed an oscillating engine RPM surge at idle. Fine at any load or speed however the engine sound a bit different under high acceleration. If I'm in gear, the car will surge forward a bit while the breaks are applied. When inside the car, it sounds like the radio is on low with a low base setting. Initially, i thought it was coming from another car.

The engine light has been on and checked. The dealer told me the timing chain is loose which has become a common problem for the SHO-V6 Twin Turbo.

Any thoughts?

 

[FrankK]

I had a rough idle on my 2016 SHO, non pp. I replaced the plugs and gapped them all to .28 idle is very smooth now. I am tuned so you might not want to go that small, but the plugs I took out were gapped all over the place, ranging from .32 to .36

 

[SHOdded]

if plugs are good, next thing to check is fuel injectors and carbon buildup on the back of the intake valves.

you can start with a GDI fuel injection cleaner, run it thru the fuel tank and see if there is any difference. if so, an induction service will be worth it. the valves should be borescoped first to check for excessive hard carbon buildup so that chunks dont break off and **** the turbos.

 

[luigisho]

Was it doing this before the new timing stuff got put on?