Grrrr and RPM needle drops below 1000...

[Pjlee25]

have you guys encounter this?

 

During idling, the RPM needle drops and the car will make this "GRRRRR" noise...after which, the needle gets back up and car went into the normal idling. This occurs about every 7-8 mins during idling.

 

What's wrong???

[Xavina]

Wah, question is, why would you let your car idle for 7-8 mins?

[Pjlee25]

Sometimes, no choice... traffic jam? :) or hang around in car waiting for people?

[Jetabout777]

I used to experience this with a particular car and the engine warning light came out.

 

Sent back to dealer to check and was told car seemed to be fine, but was told to better send it in for a diagnostic check. I didn't bother until recently when things got worse.

 

Now the car fluctuates from 600rpm all the way to 2000+rpm not only at idle, but when engaged in gear as well, so there is a certain involuntary acceleration when the rpm automatically goes up to 2000+rpm even when I am braking. When cranked, it will go up to 4000rpm.

 

Diagnosed it and was told problem with the intake manifold air distributor, in particular with the air intake case and intake manifold. Need at least $5k to change

Edited December 26, 2010 by Jetabout777

[Mutant]

Try cleaning your throttle body & check your air filter condition.

[Antonee]

I used to have this problem to my car as well.. Rpm suddenly drops and engine stall.

Sent back to CNC and throttle body was cleaned... car back to normal. But, problem came back again...rpm dropped to almost engine wanna stall.. I have to keep the rpm going up in case it stalls again

 

Back to CNC, diagnosed it again and was told that the idling valve malfunctioned..I have it replaced and car is back to normal..

[Copen]

Ya prolly, throttle body is dirty. Get it cleaned up first then monitor again.

[Keithchue]

also your air box....this also happend to me once, my mech...just cleaned the air box..everything is fine.

[Good-Carbuyer]

Seems similar to my Accent '01 that I trade-in earlier. The used Accent was fantastic when I bought it. After a few months such observations repeatedly were made. Computer diagnosed in order. A week or two later the same issue. I wonder if pre-programmed to breakdown?

[Pjlee25]

Thanks for reply, mates. :)

Is there some kind of cleaning kit/solution that i can get off the shelf to work on the valve and throttle body?

 

of course, if need to... will have to drop by the workshop, which is a chore...

[Mona-vie]

Sometimes, its due to idle control valve. Get remove it and get it cleaned.

 

Btw, does it remain at lower RPM for a long time or it just drop and goes back up?

 

If it does goes back up, it normal. This is usually caused by the aircon compressor. When compressor clutch engages, there will be load and the engine RPM will suddenly drop, then the ECU will compensate for the load and bring the RPM up.

 

Sometimes, you may see the RPM goes up and comes down again. This is when the clutch disengage. There is suddenly drop in load on the engine, thats why RPM goes up. Then ECU compensates and bring in down.

 

Its unavoidable esp. for older cars.

[Pjlee25]

  On 12/28/2010 at 1:07 AM, Mona-vie said:

Sometimes, its due to idle control valve. Get remove it and get it cleaned.

 

Btw, does it remain at lower RPM for a long time or it just drop and goes back up?

 

If it does goes back up, it normal. This is usually caused by the aircon compressor. When compressor clutch engages, there will be load and the engine RPM will suddenly drop, then the ECU will compensate for the load and bring the RPM up.

 

Sometimes, you may see the RPM goes up and comes down again. This is when the clutch disengage. There is suddenly drop in load on the engine, thats why RPM goes up. Then ECU compensates and bring in down.

 

Its unavoidable esp. for older cars.

 

 

Yo! Yes, it drops and goes back up after the "GRRR".... I guess maybe so... old car! :)

 

Happy New Year to all!