Idle Issues with AC on

[Jgranville]

Hi Guys,

I have been having some idle issues with my 2000 Expo XLT with a 4.6 engine. Just for some background on the car, it was my moms daily driver for the first 10 years of its life. 90% of that was city driving. For the last four years, it has been our commuter car to school for my sister and I and just about everything is highway driving. I'm just over 160,000 miles. My parents drove from SF to LA to pick up my sister from college. On the way down, my dad said he was having issues with the AC(same temp as cold panel air). Cruise control would also randomly shut off. On the way back, same issues but the idle was extremely rough and it stalls at stops signs and lights if you don't keep your foot on the gas a little. It's even worse going down hills in 2nd. I work in a garage after school and looked the car over with our master tech. We found no vacuum leaks. I replaced the IAC unit and still have the same issue. Idle sucks and and it stalls.

Any one have a clue what it could be? Like I said, at idle in drive, if you turn on the AC it drops below 500 rpm and either stalls or starts to crap out and revives itself.

I'm also having a lot of slipping in the transmission. I hit the gas and the engine revs and the ride is slow and rough, then all of a sudden something feels like it's grinding, and then in jumps and jolts a few times and we're off.

I appreciate the help y'all

Thanks

 

[bedrck46]

when was the last time the throttle body exhaust ports were cleaned?

 

[Jgranville]

Less than a month ago with sea foam

 

[bedrck46]

did you remove the throttle body to clean out the exhaust ports ??

 

[Jgranville]

I have not done that. I only cleaned in front of and behind the butterfly, sucked some through a vacuum line to decarbonize, and then put about half the bottle in the gas tank.

 

[bedrck46]

you wasted your time doing that Remove the throttle and check the two exhaust port that go thru the throttle body also clean the ports for the IAC

Check this video on youtube

P0401 code ford Throttle body EGR port cleaning 4.6 Ford Expedition part 1 of 5

97 F150 P0401 error code fix (Part One)

You will get a good idea as to how bad those ports can be clogged

 

[Jgranville]

Thank you bedrck46. I will be sure to check out the video and clean the exhaust ports.

Any idea on why I am getting that jumping and jolting when leaving a stop?

 

[bedrck46]

no but I think you will see some improvement after cleaning the throttle body If you can take a pic of the exhaust ports It will be interesting to see how bad they are clogged. When you view the video that ports on my past 99 with 4.6 looked just like those in the video.

Also check your hoses to the DPFE sensor make sure they aren't cracked And if you do need to replace them change one at a time so as to not cross them