In park or drive... it kinda goes up a little, then has a small 'click' and then the rpm goes down a little... what causes that? It is consistent and doesn't sounds 'bad' or grindy at all...
2007-05-12 16:51:41 · 9 answers · asked by Anonymous in Cars & Transportation ➔ Maintenance & Repairs
As soon as I started reading the question, I knew exactly what it was. When I looked at the answers, Tim M got to it first. He (and I) are the only two (so far) that knows what it is. The others either are over-analyzing what appears to be a symptom of a (non-existing) problem, or they just don't know what they are talking about and just want the points for guessing. It is a very common noise that is the electronic clutch engaging (the click) on the A/C air compressor. When engaged, it adds an additional strain on the engine and therefore "bogs down" the engine, resulting in lower RPM's. When the A/C no longer needs the air pressure from the compressor to cool the air, it disengages the clutch (another click) and the strain is then released, resulting in an increase in RPM's to the normal idle speed. If you want to know how the A/C system works, you'll have to ask another question. ;)
2007-05-12 17:11:36 · answer #1 · answered by Jennifer C 2 · 3⤊ 0⤋
When Driving: I'm assuming you're driving an automatic with overdrive. Overdrive is just shifting up one gear when cruising at the same speed. This keeps the momentum of the car going forward while having the engine work less hard. It improves gas mileage and causes the RPMs to drop.
When In Park, Idling: This is also to decrease the RPMs of the engine and conserve fuel. In a manual, when I depress the clutch, my RPMs drop dramatically, because the engine is not connected to the driveshaft, therefore it does not have to work so hard, just enough to stay running. Your automatic should be no different. They still have multiple forward gears, you know. :-)
Watch and listen to see if anything sounds unnatural. My van used to do that all the time. It was normal. Also, if you know a car guy/girl that can check it out in person, ask them.
2007-05-12 23:59:38 · answer #2 · answered by Anonymous · 0⤊ 2⤋
If its associated with that click that the rpms drop its pobably the air condition compressor starting, then when it stops it will raise the rpms back up because the strain of the compressor is then gone. The click is the sound of the clutch that turns on the compressor.
2007-05-13 00:00:04 · answer #3 · answered by Tim M 1 · 3⤊ 0⤋
Could be a fuel pressure regulator diaphram starting to go out.A vacuum leak will cause a variation in idle and eventually stall with no restart.
2007-05-13 00:40:30 · answer #4 · answered by (A) 7 · 0⤊ 1⤋
I had the same problem in a Honda I used to have, it's the throttle idle sensor, it has shifted some and it just needs to be moved back and tightened. Hope it helps!
2007-05-12 23:57:48 · answer #5 · answered by Kane 3 · 0⤊ 2⤋
sounds like the air conditoiner kicking on and off. also could be a vaccum hose off somewhere or the throttle position sensor is bad.
2007-05-13 00:49:02 · answer #6 · answered by pot_sex_beer 2 · 0⤊ 1⤋
Its kind of easier if you give the model and year,but not knowing that I would look for a vacuum leak somewhere or it could need a tune up,dirty fuel filter and the list would go on.
2007-05-12 23:57:26 · answer #7 · answered by sasyone 5 · 0⤊ 2⤋
it because you van has automatic if it kept going up you car would die
2007-05-12 23:54:58 · answer #8 · answered by car fanatic 3 · 0⤊ 2⤋
vaccuum hose...... maybe
2007-05-12 23:54:33 · answer #9 · answered by theevilfez 4 · 0⤊ 2⤋