Rpm Idle

ashraf · July 18, 2011

what is the normal RPM on N & D positions (auto/1500 cc)?

and when we switch on the AC, the RPM should go higher or lower

what is idle RPM ................

Uditha88 · July 18, 2011

On 7/18/2011 at 7:47 AM, ashraf said:

what is the normal RPM on N & D positions (auto/1500 cc)?

and when we switch on the AC, the RPM should go higher or lower

what is idle RPM ................

Idle on N = 700

When D about 600

When AC on, again about 600. Means due to the load on engine, RPM goes down.

ashraf · July 18, 2011

On 7/18/2011 at 11:28 AM, Uditha88 said:

Idle on N = 700

When D about 600

When AC on, again about 600. Means due to the load on engine, RPM goes down.

thanx uditha

any other ideas.......!

nexus · July 18, 2011

On 7/18/2011 at 3:31 PM, ashraf said:

thanx uditha

any other ideas.......!

your rpm drop below 450? what is the car model?

ashraf · July 19, 2011

No, mine is on between 500-600.it's a 2002 mazda familia

harshansenadhir · July 19, 2011

On 7/18/2011 at 11:28 AM, Uditha88 said:

Idle on N = 700

When D about 600

When AC on, again about 600. Means due to the load on engine, RPM goes down.

Idle RPM depends on vehicle Make/Model and may be engine type as well. Further, When the A/C is switched on, RPM should rise, provided that the idle up mechanism works properly. With a working idle up system, engine will rev higher to compensate the additional load on the engine due to compressor + condensor fan/auxiliary fan and to provide effective cooling/gas recirculatioin of the A/C system. If the RPM goes down with the A/C on, that means a makabass has messed up with the idle up mechanism.

ashraf · July 19, 2011

my idle up mechanism was ok, but I want to clarify my Doubt !

'coz some say When the A/C is on, RPM should rise some say RPM must go down.

anyway thanx 4 ur reply dude.

harshansenadhir · July 19, 2011

On 7/19/2011 at 5:31 AM, ashraf said:

my idle up mechanism was ok, but I want to clarify my Doubt !

'coz some say When the A/C is on, RPM should rise some say RPM must go down.

anyway thanx 4 ur reply dude.

Those who say it should go down are wrong. Simple

Archon · July 19, 2011

harshansenadhir is correct.. when AC is turned on the RPM should go up slightly.. anyway it may depend on the make and model. try to download the manual of your car from the website there you can find the exact idle RPM.. as i remember a toyota 110 idle should be 750. idle RPM is very important to maintain the necessary oil pressure at idle , + engine mount health + correct emission range etc etc..

Cheer,