2.4 GDI Idle problem

[prelude4dh]

I have a 2000 Galant 2.4 gls gdi automatic.. The car runs great but when sitting at idle the revs jump up and down, nearly cutting out and has cut out once or twice. After cutting out the car starts no problem. This problem seems to get worse when the engine heats up. Just wondering if anyone has had the same problem and could shed some light on this for me before I start buying parts. Thanks.

[Mitsitech001]

Hi there,
the problem with GDI is that they tend to accumulate carbon in the inlet and the throttle body and this causes lots of idling problem. What I use to do in such situations is to strip down th inlet and send it to the rebuilders to be cleaned. I also spray a product called "schuma" (available from the MMC dealer) in the inlet passages in the head and leave it overnight.
Your vehicle should be back running sweet after this.
Good luck.

[jwk316]

Thats not the problem. I have a 98 galant and I didnt everything from a tuneup on teh car to trying many different things. I ran a tester and it said it was the egr valve. Well, I know for you its also not the egr valve. Its the valve assembly that comes from the egr valve. It was about $70 for me to buy it from the dealer. This is your problem. I am 100% sure. its commen in the 2.4 galants. I put over $500 in tuneup items alone and finally found this was the problem. If you need help finding it or whatever let me know.

[Wasted Tracy]

Hope this solves your problems. I have a 99 Galant and had the same problem and I was something very simple, and inexpensive. Or...sorry to say, it may be pretty expensive if not fixed in time. I had boot problems on the ignision coils and plugs. Check the boots covering each spark plug and see if there are any marks on the opening (looks like burn marks, or small scratches) if there are then you have spark plug issues. This can be fixed by replacing plugs with factory issue plugs, and replace boots also. You don't have to buy the whole ignision assembly just the boots (I know, because I made that mistake). This is usually caused by buying plugs at a parts store, as they give you something that says their for your car (not your fault). If that isn't it. It may be your converter on your exaust. If this is the problem, your looking at approx. $700.00 just for the parts. Most likely it would be the plugs (one or more), and it's easy to check, and do yourself. Sorry to say...with Mitsubishi you usually have to buy factory direct to be safe. Good luck and I hope I helped you out, and sorry if I wrote so much.

[sparkeykev]

Originally Posted by prelude4dh

I have a 2000 Galant 2.4 gls gdi automatic.. The car runs great but when sitting at idle the revs jump up and down, nearly cutting out and has cut out once or twice. After cutting out the car starts no problem. This problem seems to get worse when the engine heats up. Just wondering if anyone has had the same problem and could shed some light on this for me before I start buying parts. Thanks.

Check your idle air control valve they have problems with those

[lancescott67]

I just found my 2000 2.4 has a cracked intake behind the throttle plate mounting flange. It caused rough idle, erratic at times, in general all the problems you have with a vacuum leak. I'm guessing my problem was caused by worn motor mounts that caused to much movement. It was easily found by spraying brake clean on it. BTW- It did not set a check engine light.