Low idle

Tiny
STEVE MURRAY
  • MEMBER
  • 2004 FORD FREESTAR
  • 4.2L
  • V6
  • FWD
  • AUTOMATIC
  • 175,000 MILES
Van runs rough until 2000 rpm idle drops the warmer van gets.
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Wednesday, May 31st, 2017 AT 1:17 PM

11 Replies

Tiny
STEVE W.
  • EXPERT
Classic symptoms of a vacuum leak. Probably needs intake manifold gaskets. The manifold cools down overnight and pulls away slightly, You start the engine and it draws in excess air giving you a high idle and rough. As it warms up the parts expand and start to seal back up and the engine runs better because it is now under computer control. These are common for leaks between the upper and lower intake manifold sections. The pictures show the o-rings and lower gaskets that fail. Normally I test both the upper and lower gaskets, It is not that much more work to do the lowers as you have the engine apart anyway.
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Wednesday, May 31st, 2017 AT 3:35 PM
Tiny
STEVE MURRAY
  • MEMBER
I have change them and the revs get worst when it warms up
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Tuesday, June 6th, 2017 AT 5:39 AM
Tiny
STEVE W.
  • EXPERT
What are they when you start it vs once it warms up? Do you have access to a scan tool? I'm wondering if the ECT sensor is acting up as well. Does it start hard as well as idle wrong?
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Wednesday, June 7th, 2017 AT 1:54 AM
Tiny
STEVE MURRAY
  • MEMBER
It starts first try the revs are 1100 and when it warms up the go between 800 to 500 rpm I don't have access to a scan tool
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Saturday, June 10th, 2017 AT 3:53 PM
Tiny
STEVE W.
  • EXPERT
OK so on cold start it revs to 1K, that's common as the engine tries to warm up quick. Then it should drop back to around 650 or so and stay there. Try cleaning the throttle body and the idle air control ports, Then test the IAC for operation. Normally they fail and stick in one spot but it's possible it's sending bad data.
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Monday, June 12th, 2017 AT 6:29 PM
Tiny
STEVE MURRAY
  • MEMBER
The throttle body has bin cleaned and the iac has bin changed
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Saturday, June 17th, 2017 AT 1:23 PM
Tiny
STEVE W.
  • EXPERT
OK so you cleaned the TB, IAC is good and no vacuum leaks. But it still acts up.
At this point you really need a scan tool with live data to see what the timing and fuel trims are doing. The engine coolant temperature sender on these likes to cause problems but without a scan tool you can't see if it is the problem.
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Sunday, June 18th, 2017 AT 4:31 AM
Tiny
STEVE MURRAY
  • MEMBER
Ok got a scan tool and when you rev it quick to 2000 rpm the vacuum goes from 18 down to 2 than up to 20
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Saturday, June 24th, 2017 AT 5:39 PM
Tiny
STEVE W.
  • EXPERT
What does the coolant temperature sender show on a cold engine and once it warms up?
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Sunday, June 25th, 2017 AT 5:41 AM
Tiny
STEVE MURRAY
  • MEMBER
Ill find out tomorrow and let you know
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Sunday, June 25th, 2017 AT 8:35 PM
Tiny
KEN
  • ADMIN
Please let us know what happens.

Cheers, Ken
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Wednesday, June 28th, 2017 AT 5:05 PM

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