Car idling rough in P/N but smoothens out in D/R while stopped

[taimurahmed92]

I have a 2005 Lancer 1.6 GLX CVT SR with 116,000 km. Lately the car has been idling rough. No rpm fluctuations.....only vibration at idle in P or N. When I move it into gear in R or D the car vibrates for 2-3 seconds and then smoothens out like a new car and stays that way till I move it to N or P.

What could be the problem?

[khuram2703]

Throttlebody service required.

If its ok than Mountings as the mountings of Auto cars deteriorate way earlier due to continuously under stress as compare to manual.

[taimurahmed92]

List of work done in the last one year:

All four mountings changed in the last 7 months.

PCV valve + PCV gasket changed.

IACV assembly changed 8-9 months ago.

Spark plug seals and rocker cover seal changed.

Alternator bearings changed.

Exhaust manifold to pipe washer changed.

Timing belt + tensioner + drive belts changed.

All of the above were some major stuff due after 12 years. I can’t figure out what may be causing the rough idling issue. Throttle service has not fixed it.

[khuram2703]

Mountings new or kabli?
Especially gear mounting as it is related to gears when shifted from P or N to D or R.

Service and recalibrate the Throttle body and make sure atleast Gear mounting should be new geniune.

[taimurahmed92]

All parts mentioned above are Mitsubishi genuine imported either through Dewan or another importer. I’m not a proponent of kabali parts. All made in Japan.

[Naweed]

Mountings would behave oppositely .. smooth on idle and rough when in gear while car is not moving
very odd problem .. no exact idea but one thing is being pointed out .. idle control .. may be its dropping rpm in idle but as soon as u engage gear it accelerates .. there r two minor idle adjustment screws .. one on throttle body .. try adjusting it a bit on normal idle ..

• make sure u note its original position before changing screw adjustment
• ur idle rpm should be 850-900 ,, have u tried using ac on idle .. does it smooth out on idle

[Naweed]

on a second thought it could be foundation (mounting) .. may be the one on gear side behaves differently .. here is a check .. slightly support engine with car jack .. if vibrator goes away in idle then it is a bad mounting .. do not damage any engine part while using jack .. just a precaution

[taimurahmed92]

It does not smooth out on AC either. Sometimes it smoothens out by itself and the car becomes silky smoothly idle. If you give slight throttle to increase rpm to 1,000 even then it is silky smooth. Drive is silky smooth too even with AC.

This is sth very minor in my opinion but annoying as hell. Mountings are all brand new Mitsubishi genuine made in Japan.

The rpm does not fluctuate while idling. It stays the same until you move the steering or turn on AC. However, even with constant rpm the vibration is still there.

Another interesting thing. On some days the car isles smooth on N and vibrates in D......and some days it vibrates in N and is smooth in D. Now this is strange

[rare]

my lancer used to behave smooth like brand new car while test drive by mechanics and i had a thought "koi Jin hai is mein".

Best of luck for resolving this issue

[taimurahmed92]

I avoid mechanics for these small things because mostly they get on my nerves by suggesting that plugs are bad, coils are bad, injectors holes have opened, etc. whereas online inquiry and troubleshooting mostly shows it as minor stuff.

[Rahat083144]

It could be a whole host of things, but what you can do yourself, easily, is clean the throttle body and IAC. Even if it doesn't solve the problem, it will do no harm. I'm sure you know the below, but still explaining it:

For throttle body, all you need to do is loosen the screw on the rubber air pipe and remove it. Since its not a drive-by-wire, you can manually open the butterfly and clean it.

Just below the throttle body is the IAC valve, held on by 3 screws. Loosen and remove them, unplug it clean it with carb cleaner and put it back. IAC valve going bad is a common problem in the 4G13/4G18 engines, so cleaning it wont do any harm.

[taimurahmed92]

Agreed. My IACV went bad last year and I had the complete assembly changed (servo + housing).

I’ll still clean the throttle body and see if it helps.

[aliaamar1101]

This post was flagged by the community and is temporarily hidden.

[taimurahmed92]

I am in Islamabad. I’ve already listed the parts I’ve changed in the car over the last one year.

I believe the culprit is either a dirty throttle body or an improper tappet adjustment because the gauges in our market don’t have lancer’s values. You need a good gauge like this one which has the thickness for both hot engine and cold engine valve clearances.

http://www.reliabilitydirectstore.com/mobile/Product.aspx?id=2146

[aliaamar1101]

This post was flagged by the community and is temporarily hidden.

[taimurahmed92]

Mitsubishi Islamabad Motors are looters. They always mess up the car.

[judgevt]

When did you last change your transmission fluid??

[taimurahmed92]

Yes, but about 40,000km ago. It’s still red and in good condition.

[aliaamar1101]

This post was flagged by the community and is temporarily hidden.

[taimurahmed92]

Okay