1999 Dodge Caravan

WANPELA

MEMBER
1999 DODGE CARAVAN

Transmission problem
1999 Dodge Caravan 6 cyl Two Wheel Drive Automatic

Recently our van has had driving issues. From a stop, engine RPM's would go very high and the vehicle would move slowly but still get all gears eventually. I changed the transmission fluid and filter (purchased from the Chrysler dealer).
The van has worked without problems for 3-4 weeks.
The other day I turned on the AC as it was hot at a red light. When the compressor clutch engaged there was a slight ripple in engine RPM, but when accelerating off the red light, engine RPM's went very high again, as the van crawled slowly through each gear. When I turn off the AC, the car acts normal. Any ideas?

4 Replies

RASMATAZ

MECHANIC
75,992 POSTS

Check and test the idle air control motor/throttle position sensor and manifold absolute pressure sensor.

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Tuesday, April 20th, 2010 AT 11:49 PM

WANPELA

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2 POSTS

The IAC valve and TPS haven't triggered any codes so far. I see a test for the IAC valve in the manual, but nothing for the throttle position sensor. How do I test that, other than just replacing it?

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Wednesday, April 21st, 2010 AT 9:08 AM

RASMATAZ

MECHANIC
75,992 POSTS

You need to test the closed and wide open throttle voltages.

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Wednesday, April 21st, 2010 AT 12:05 PM

WANPELA

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2 POSTS

On our Dodge Caravan, whenever any setting on the blower fan is selected, the a/c kicks in and makes a grinding noise as it is running (even if hot is selected). This is also when the van is very sluggish to accelerate after a stop and engine RPM's are very high before it shifts through the gears. Can I just change the clutch on this compressor or perhaps the grinding sound as it is running is a bearing or something inside the compressor is slowly self destructing?

Secondly, I haven't got to it yet but you had mentioned the IAC being a possible problem. I was wondering how the IAC valve could cause the "symptoms of a slipping transmission"?

(I was trying to read some stuff and work it out, but I don't know!) - In that from a stop with the a/c on we get a sluggish van and high RPM's through each gear shift.

The IAC is just basically a air bypass across the throttle plate, unless it senses something from the a/c system. What would cause the RPM to go high and affect the engine-transmission interface?
(Sorry for all the questions here!)

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Friday, May 7th, 2010 AT 4:38 PM