110 RPM changing according to the engine heat

[pasindups]

I have a Toyota AE110 with Automatic gear box. The engine is starting and running smoothly when the engine is in cold state, the RPM is normal (No RPM meter because it is a XE Saloon. I am telling according to the engine sound) and no vibrations (Recently replaced mounts but the issue was there previously) or knocking sounds. But when it is getting the normal engine running temperature , the RPM is getting lower and start vibrating while idling on gear "D" &"R" but "P" & "N" is smoothly having the normal RPM in any of the engine temperature. While ON/Off the A/C in idling, the RPM is slightly changing but not up to standard. Any help guys ?

[aamarakoon]

May be the engine mounts are bad. Anyway check the RPM correctly as this could be subjective since you don't have an tachometer.

[pasindups]

I changed engine mounts (original), timing belts and other belts

[pasindups]

Air filter is very bad. If I do a tune up for the vehicle, Will this problem solve?

Edited December 5, 2016 by pasindups

[PerfMad]

Hi Machan

First do a proper engine tune up.. During the tune up make sure that your,

- throttle body and injectors are cleaned properly

- Spark plugs are checked and has correct gap inbetween the tips

- Plug wires are in good shape

- IACV and other related sensors are cleaned

- Fuel pump pressure and also check for fuel filter for any blockage..

- Better replace the air cleaner if its not in good shape

Get these done first because no matter where you go, every garage will suggest you to start with this.. If you dont mind me asking, what the millage of your car ?

Keep us posted on your findings..

Cheers

[terrabytetango]

The engine will be under strain in D (or any lower gear) and R, so there might be increased vibration and a lowering of the engine note. It was quite discernible in my Vios, however excessive vibration is an issue.