2003 Lincoln Town car idles rough and neutralizes for a few seconds.

[WeReallyLovePizza]

Make

Lincoln

Model

Town car

Year

2003

Miles

67000

Engine

4.6

Hello,
2003 Lincoln town car 67,000 miles.
Sometimes when at a stoplight or coasting to one, the idle becomes slightly erratic, and the transmission neutralizes. If I wait a few seconds it goes away and back to normal. Only just started doing this. Fluid is at normal level when hot. Doesn’t smell burnt, isn’t cherry red, but more on a lighter maroon color. Fluid and filter done approx 2014 at approx 50,000 mile mark.
Never a taxi, private owned vehicle.

Can this be something other than transmission related ( I hope?!?!)

Will adding an additive help or make it worse?

Thanks In advance

 

[billr]

I moved this to the Trans forum, as our trans expert is more likely to see it here.

 

[WeReallyLovePizza]

I moved this to the Trans forum, as our trans expert is more likely to see it here.

Ok thank you

 

[bp042665]

first off if it isn't running right the transmission wont shift right as the idle starts to drop down the line pressure in the transmission will also drop causing a neutral or drop out of gear feeling i have seen this alot at my shop and trying to explain it to customer's that it's a running problem not transmission problem. i would look for a vacuum leak or a idle air control motor gummed up

 

[WeReallyLovePizza]

Hi thanks for the reply. Although the car runs fine otherwise, I will look for vacuum leaks.
What do you recommend to “ungum” the iac motor?
Thank you

 

[grcauto]

Hi thanks for the reply. Although the car runs fine otherwise, I will look for vacuum leaks.
What do you recommend to “ungum” the iac motor?
Thank you

Pull the TB and clean it well. IAC also

 

[WeReallyLovePizza]

Pull the TB and clean it well. IAC also

Ok I will try that. Thank you