Driving on the road the RPM goes higher wituout speedind

Is the check engine light on ?

code p0320 refers to cam shaft position (CKP) sensor/engine speed (RPM) sensor--circuit malfunction=== causes --wiring--CKP/RPM sensor ---ECM
because the engine runs ok until it is on cruise control I would be investigating the RPM sensor for a fault
The cruise control takes its control from the RPM sensor and if that circuit is interminable the the cruise control doesn't know what rpms to maintain.

try to increase the idle-rpm..
Example - at standstil condition when you start your van, have look at rpm... say 1000 or 1200 or 1500.. whatever it may be..
Keep idle-rpm a little bit higher, if previously it was 1200rpm then set it to 1500 rpm..
If the problem is solved then..
1) clean ur airfilter
2) check spark plug condition
good or bad... if bad then replace..
3) check fuel supply line, if it is damaged or folded

If it's running rough, chances are that it's misfiring. If the Check Engine light is flashing/blinking, it is definitely misfiring.
If that's the case, drive it as little as possible... Or straight to the mechanic because the more you drive it while it's misfiring, the higher the chance is of you ruining your catalytic converter.

I’m happy to help further over the phone at https://www.6ya.com/expert/jason_00b31cc8f593773a

Sounds like valve timing has slipped. Are the other cylinders much higher in pressure or about the same?

Difficult question with all the variables involved. I'll start by saying the Santa Fe is a decent vehicle, and has the potential to last a long time (many miles). However, as with any vehicle, how has it been driven and maintained? If you purchased it new, drove it 'gently' (no racing, wild off road driving, starting it on a 0 degree day and revving the engine to high rpm, etc) maintained it well (fluid and filter changes on a regular basis, topping off fluids (not letting the oil go down a quart before adding- top it off when its only down 1/2 qt at most), fixing anything that starts to go (before a small problem becomes a big one), you could probably get 200k miles or more out the vehicle. What kind of driving do you do? Highway mostly? The # of miles over the life of the vehicle would be highest, if you do short drives around the city, that is tougher on a car, total miles of the life of the vehicle would be less. If you bought the car used, there is the big unknown factor--how did the previous owner(s) take care of the car? Was it owned by a little old lady that only drove it to church on Sunday, resulting in 1k miles driven a year? Sounds great, but letting a car sit w/out driving is actually bad for the car. Has the car been kept clean? If it's driven in an area w/ snow, is the vehicle washed often to remove road salt? Some cars sheet metal fails before the engine and tranny do because of corrosive road salt. So, to answer your question, 'it depends..." Good luck.

This may been an ignition module or a MAF sensor, this car may need to be diagnosed using a OBD I computer code reader to accurately diagnose the problem.

Sounds like a possible fuel pump problem...When they begin to go bad they will overheat and lock up, then work fine for a while and do the same thing again. By changing the filter you lowered the flow resistance and allowed the pump to work a bit easier but still being bad, it did the same thing again. There are other things that can do this as well, but pump is most common.

Hi all,
I currently own a 2005 saturn vue and also a 2002 saturn vue. My 2005 began making the same whistling sound around 36000 miles, I let it go and let it go. Finally it got so bad I could not deal with it any longer, I have a great mechanic and he automatically point out the carrier bareing I had it replaced and my car is very very peaceful...... :) Hope this helps.

Hi, Did you notice the motor actually reving higher when the tachometer was reading a higher rpm.. If it was it could be your transmission slipping.. Set your cruise control and listen to your motor while the tachometer starts moving erratically.. Good Luck