I own a 99 Durango with 87K miles 5.2L, V8 4x4. My problem is with my RPM gauge. After the car has warmed up and I?m on the freeway (going about 65-75 mph) the RPM gauge starts to spike. Normal driving RPM?s is approx. 2000 RPM?s and it spikes to about 2500 RPM?s and returns to normal driving RPM?s. The other thing I noticed was that it only occurs on moderately bumpy roads (which are most roads); however on newly paved surfaces it doesn?t happen at all or is barley noticeable. When the spike occurs you can hear the engine rev. Initially I thought it might be transmission/differential issue, but after asking around people are telling me that it?s not. I haven?t had any issues with the transmission in the past.
Dan
St. Louis, MO
Since it looks like the tach is really following the engine RPMs the problem may be with a dirty throttle position sensor. You may be able to clean the contacts of the sensor. If not then you may have to replace it. By placing a voltmeter across the sensor output and monitoring the voltage you can see if the problem really is coming from there.
I check it out and let you know. Thanks for the reply.
That fixed the problem Cougar. Thanks for the info. It was greatly appreciated.