2.4 (4G64) GDI - Idle Problems

[ryanjames.powell]

Further to this thread: http://www.clubvr4.com/forum/showthread.php?t=42977

I had the entire intake manifold/plenum resonator taken off and cleaned, and there was not too much soot further in, so did not deem that worth worrying about.

A few days ago, I went in for a WOF and failed on excessive exhaust smoke. It has been using oil ever since I got it, and recently, with a lot of city driving and cold starting, it has got to the point of using 1L of oil for 2 tanks of petrol. My mechanic tells me after pressure testing, etc that it is almost definitely the valve seals and he is going to replace them.

My question is this: do you think that my low idle speed could be caused by bad readings from O2 sensors etc due to the oil burning and high level of exhaust smoke, and therefore it should be fixed by stopping the car using oil? And do you have any other suggestions of things to try (other than anything to do with the throttle body or cleaning out carbon because I have already done those things)?

[bradc]

What rpm does your car idle at currently?

[ryanjames.powell]

Round about 500, should be 650.

[VR4WGN]

remove your plugs packs and look for oil leaking into there,also remove the plugs and see wich 1 is covered in oil.i guess 1 or 4 will be the fault..

either way your engine is poked dude!!! ,rip it out and put a 2.5 v6 in it lol...

[ryanjames.powell]

VR4WGN, your comment is not exactly constructive, and as I said, I know where the oil is getting in, and it is being fixed as we speak. My problem (which I can put up with because it is only mildly annoying that the car shakes slightly when it's idling) is the slow idle speed. I am only looking for suggestions and if it is anything that is going to cost a lot then I won't bother because it's not really doing any harm. And apart from this one little annoyance (and the oil use I guess), I have found this to be a very nice engine with plenty of power. It's only marginally less powerful than the V6 and has a 5 speed box rather than the 4 speed.

[bradc]

They have that fancy electronic throttle so I'm unsure if they have an idle adjustment on the throttle like on the normal cars?

[ryanjames.powell]

Nah, definitely no manual idle speed adjustment. It "learns" its idle speed each time you reset the ECU (eg disconnect the battery). It will often die out a few times before it gets the settings right. You just have to sit there and start it up each time it dies and it goes through all the settings and determines what is optimal from its sensors etc which is why I think it could have something to do with a sensor somewhere.

[VR4WGN]

you can turn the tps switch wich will up the idle too... but i would advise against it..

well i hope your engine does last dude,but the future with these engines are never forever,theres none in NZ that have actually been well maintained and looked after so they dont last long.

short term- keep the plenium acid bathed,plugs clean,coil packs working,and watch your oil level,and now and then check for fault codes on the MAF or Throttle bodie as these 2 are common failures apart form the packs,constructive enuf?

[ryanjames.powell]

I'm sorry if I sounded pissed off but you must admit just telling me my engine is poked when it isnt is not really very nice.

Turning the TPS will change the idle speed for a little while, but the computer does compensate and change it back to the speed it was before (I tried turning the APS, which is essentially doing the same thing. I took it for a 5 minute drive and it was back the way it started again).

I actually think my car is in very good condition besides the oil thing (which will be fixed by the end of the week). It was only in NZ for 20000km before I bought it and since I bought it I have had it serviced every 10000km and run it only on 98 octane petrol. I use the correct 10W30 oil in it too. It runs very nicely apart from the idling. I think it will last quite a bit longer yet. But yes I take your point about these engines in general - I just feel that if they are taken care of properly then they are actually reasonably good.

[Johny]

your lucky then if i leave me oil for longer than 5000 km it gets really dirty and nasty

[ryanjames.powell]

your lucky then if i leave me oil for longer than 5000 km it gets really dirty and nasty

My oil stays reasonably clean, but then again, I was replacing 1L of it every 1500-2000km

When it's fixed it will be interesting to see how dirty the oil gets when it isnt burning it.

[VR4WGN]

economy i cant complain with these engines theyr really good TBH but yea the tempramentalness is a bit OTT for an engine i think ,lol,they should be built to handle lol... ps i gota GDI CLUB Sticker if you want it lol,gota clover leaf on it too lol

[Rambaud]

My GDI has done nearly 150,000 miles (~ 241,000 km), and passes the MOT emissions with no problems.

The engine does seem to benefit from good oil (I use Amsoil 0W-30) with frequent changes. I change my oil and filter every 3 months or so - as I have only been doing very short daily journeys lately.

[ryanjames.powell]

ps i gota GDI CLUB Sticker if you want it lol,gota clover leaf on it too lol

Mine came with all the original Manuals and paperwork, including a GDI Club sticker

[ryanjames.powell]

My GDI has done nearly 150,000 miles (~ 241,000 km), and passes the MOT emissions with no problems.

The engine does seem to benefit from good oil (I use Amsoil 0W-30) with frequent changes. I change my oil and filter every 3 months or so - as I have only been doing very short daily journeys lately.

From what my mechanic said, some of these engines had problems with oil usage from practically new. I just happen to have been unlucky and got a bad one I think. But it doesn't sound like the repairs will cost too much.

[Rambaud]

From what my mechanic said, some of these engines had problems with oil usage from practically new. I just happen to have been unlucky and got a bad one I think. But it doesn't sound like the repairs will cost too much.

I am not aware of any oil issues here in the UK with the GDI engine, it's mainly coking it up - usually from not revving it to the redline.

[VR4WGN]

yea the Mivec Lengum i got has all the paperwork too,wich is cool ,the engine form this is in Good condition as there was 1 owner in NZ and they looked after it.. so iv rebuilt the engine to go into the Charriot lol..

[crazydriver81]

TBH guys, the GDI engines suffer from too economic drive style. If you always drive with the GDI lamp lightened up, your engine will be full of dirt and residues in short time.

From my experience with the GDI engines:
- block EGR valve where pipe joins inlet manifold
- use 10W-40 or 5W-40 and change every 7.5k - 10k kms
- drive more often in higher revs to raise engine temp and burn dirt at the valves

The lower revs are mainly driven from dirty inlet valves. The valves get dirty from the exhaust gases, which are sucked in through the inlet manifold. This dirt causes irritation of all the computer stuf linked to the engine and irritates the ECU as well.

The EGR valve is linked to the GDI lamp. Whenever you drive with the GDI lamp lightened up, the EGR valve is open and a part of the exhaust gases is sucked into the cylinder (through inlet manifold).

An EGR valve is nothing special to engines, but on normal engines, the air-fuel mix is cleaning the valves chemically. This is missing on GDI engines, so it must be cleaned mechanically (so called "carbon blaster"). Mitsubishi used a system with compressed air and walnut shells to clean the engine valves from those residues.

From my point of view, I would say, get the valves cleaned and avoid all this by blocking off the EGR valve at the inlet manifold. Afterwards disconnect the battery and relearn the ECU.

cheers

[Rambaud]

And does not 98 RON petrol burn "cleaner" than 95 RON?

I have always used Shell V-Power/Tesco 99/BP Ulimate to minimise carbon build-up in my GDI.

[ryanjames.powell]

Like I said, I don't think the valves are really that dirty, because when I had the intake manifold off, the carbon coating seemed to be very minimal at the ports, therefore the mechanic did not deem it worthwhile to clean in further.

Also, I'm not one of those people who likes to try and keep the GDI light on. It is infuriating to drive that slow. I usually drive in tiptronic mode and change gear at ~4k RPM. My mum has been known to drive it like that though and she got fuel economy of around 7.5L/100km!!! I get around 8.5 on long trips.