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GDI engines
Posted: September 1st, 2011, 9:55 pm
by singchef15
So my mechanic told me that 4G93 GDI engines are not that good. Is this true?
Re: GDI engines
Posted: September 2nd, 2011, 10:43 am
by TeamH2O
If you dont maintain it properly.
Re: GDI engines
Posted: September 2nd, 2011, 3:03 pm
by 2nil
these engines really work great,but requires proper maintenance
Re: GDI engines
Posted: September 2nd, 2011, 4:09 pm
by singchef15
hmmmmm, the way he made is sound it's like those engines are absolutely no good. I had the opportunity to get one and passed it up based on his advice.
So here I am still looking for a fuel injected 4G93 engine.
Re: GDI engines
Posted: September 2nd, 2011, 10:18 pm
by rollingstock
^ I don't understand, the 4g93 gdi is fuel injected, just direct injection as the name states.
As stated before they are great engines once maintained properly, they do have inherent problems that you need to inform yourself about before contemplating purchasing one.
Re: GDI engines
Posted: September 2nd, 2011, 10:52 pm
by singchef15
Rollingstock can you help inform me? That's why I am here. Or can you send me a link that can give the information you speak of.
Re: GDI engines
Posted: September 2nd, 2011, 11:11 pm
by rollingstock
It's been discussed so many times on 2nr, just do a search for gdi.
Major problems is the high pressure fuel pump, i've personally never got this problem, then there's the noisy lifters, must use premium, carbon build up in the engine, iacv valve that acts up and causes erratic idle.
These problems can be very frustrating and can even lead to a dead engine in most instances. There are other minor problems too, but then again all engines have problems.
Educate yourself before deciding to buy, biggest deciding factor is the age of these engines now, even if properly maintained normal wear and tear would be manifesting itself now.
Re: GDI engines
Posted: September 5th, 2011, 2:37 pm
by singchef15
Well I looked it up and I understand the worry about them. I have a serious problem though as I need to choose but would really like some more advice as to them. I now have a chance to purchase a 2006 4G94 GDI but my mechanic is still advising against it.
Really don't know what to do

Re: GDI engines
Posted: September 5th, 2011, 2:54 pm
by rollingstock
^ Is that the E-throttle?
The magnet for the throttle body has a tendency to break or come off, easy fix but can be a pain.
Buying any used vehicle is a huge risk, go with your gut feeling, i've known persons who have bought b14's and corolla nze's due to the reputation for reliability and got seriously burnt.
I bought a GDI galant in 2002 f/u despite advice against it and never had any problem just regular maintenance and an alternator cold solder problem, and mounts and such, still going strong 224xxxkm later.
Re: GDI engines
Posted: September 5th, 2011, 8:22 pm
by diamonds are forever
i have a 4g94 gdi about 4 years now without any problems whatsoever, just changed oil every three months and timing belt once and still going strong. That engine has some good power to it too.
Re: GDI engines
Posted: September 5th, 2011, 9:49 pm
by singchef15
Well if I can find a 4G93 Gdi again I will seriously consider taking it. I just spoke to someone I know who has a (shark mouth galant) and he said he has had absolutely no problems with his GDI.
Re: GDI engines
Posted: September 5th, 2011, 10:03 pm
by diamonds are forever
Boy I love my galant, was thinking about selling it but when I drive other cars none is in comparison to the ride and roominess of the galant, very economical for a 2 litre engine too! Change my mind, don't want any small car again!!!!!
Re: GDI engines
Posted: September 6th, 2011, 12:18 pm
by 2nil
btw guys wat is d recommended engine oil 4 these 4g93 gdi thanx.
Re: GDI engines
Posted: September 6th, 2011, 2:09 pm
by rollingstock
Considering the age of the vehicle, once you're not burning oil i would recommend a 40 body.
Re: GDI engines
Posted: September 6th, 2011, 3:46 pm
by ek4ever
Here's an interesting read on GDI and DI in general
http://www.eurosport.org.nz/forum/viewt ... f=5&t=7724It appears that Mitsu is moving away from DI since it did not deliver on the fuel economy gains as promised. Honda also realised that DI offered no significant advantage and produced only the K20B which was DI with an ultra-lean burn of 65:1. Honda realised that they got better results with their VTEC-E which was also less complex and proven.
I think Mitsu is also foregoing DI in favour of using MIVEC to attain better fuel economy. In fact I believe they have stopped production of DI engines.
If you get a chance, examine the intake manifold of a GDI engine and see if you notice the soot buildup.
Re: GDI engines
Posted: September 6th, 2011, 8:16 pm
by singchef15
ek4ever wrote:Here's an interesting read on GDI and DI in general
http://www.eurosport.org.nz/forum/viewt ... f=5&t=7724It appears that Mitsu is moving away from DI since it did not deliver on the fuel economy gains as promised. Honda also realised that DI offered no significant advantage and produced only the K20B which was DI with an ultra-lean burn of 65:1. Honda realised that they got better results with their VTEC-E which was also less complex and proven.
I think Mitsu is also foregoing DI in favour of using MIVEC to attain better fuel economy. In fact I believe they have stopped production of DI engines.
If you get a chance, examine the intake manifold of a GDI engine and see if you notice the soot buildup.
Very interesting...
Re: GDI engines
Posted: September 7th, 2011, 2:13 am
by xtech
GDI was very good tech......still is but more expensive 100 octain fuel an having to recirculate exhaust gasses to lower its NOX levels was its down-fall.........
Hyundai has brought the rights to this Tech and improved it with 21st century upgrades lets see how it runs
Re: GDI engines
Posted: September 7th, 2011, 4:37 pm
by ek4ever
xtech wrote:GDI was very good tech......still is but more expensive 100 octain fuel an having to recirculate exhaust gasses to lower its NOX levels was its down-fall.........
Hyundai has brought the rights to this Tech and improved it with 21st century upgrades lets see how it runs
Not saying it isn't good technology, but it had specific requirements for it to be successful, low sulphur fuel and less dependency on EGR to meet emissions requirements. In fact had Mitsu used downstream NOX treatment and less EGR the outcome might have been better. As it is the issue is allowing consumers to think that this is just like non-DI engines so just use appropriate octane fuel and yuh good. Sadly that wasn't the case.
I think if you do a comparison of any manufacturers DI and non-DI engines you'll see that they are getting more benefits with valve control rather than fuel injection trickery. Another -ve is that the lean burn in most applications I've seen is not practical. In everyday driving it is difficult to keep the vehicle in this mode as any slight load increase causes a change back to stoich. So while the engine is capable of lean burn and greater fuel economy, the % of your commute that will fall under this mode will be very little.
Re: GDI engines
Posted: September 7th, 2011, 6:59 pm
by raybic
have a 4g93t gdi and its whats the tuners say, if u maintain it u wont have any problems.
Re: GDI engines
Posted: September 8th, 2011, 11:06 am
by ZeroOne
ek4ever wrote:xtech wrote:GDI was very good tech......still is but more expensive 100 octain fuel an having to recirculate exhaust gasses to lower its NOX levels was its down-fall.........
Hyundai has brought the rights to this Tech and improved it with 21st century upgrades lets see how it runs
Not saying it isn't good technology, but it had specific requirements for it to be successful, low sulphur fuel and less dependency on EGR to meet emissions requirements. In fact had Mitsu used downstream NOX treatment and less EGR the outcome might have been better. As it is the issue is allowing consumers to think that this is just like non-DI engines so just use appropriate octane fuel and yuh good. Sadly that wasn't the case.
I think if you do a comparison of any manufacturers DI and non-DI engines you'll see that they are getting more benefits with valve control rather than fuel injection trickery. Another -ve is that the lean burn in most applications I've seen is not practical. In everyday driving it is difficult to keep the vehicle in this mode as any slight load increase causes a change back to stoich. So while the engine is capable of lean burn and greater fuel economy, the % of your commute that will fall under this mode will be very little.
lean burn works well in short runs and in traffic.
lean burn goes out the window after 110km
Re: GDI engines
Posted: September 8th, 2011, 12:55 pm
by ek4ever
ZeroOne wrote:ek4ever wrote:xtech wrote:GDI was very good tech......still is but more expensive 100 octain fuel an having to recirculate exhaust gasses to lower its NOX levels was its down-fall.........
Hyundai has brought the rights to this Tech and improved it with 21st century upgrades lets see how it runs
Not saying it isn't good technology, but it had specific requirements for it to be successful, low sulphur fuel and less dependency on EGR to meet emissions requirements. In fact had Mitsu used downstream NOX treatment and less EGR the outcome might have been better. As it is the issue is allowing consumers to think that this is just like non-DI engines so just use appropriate octane fuel and yuh good. Sadly that wasn't the case.
I think if you do a comparison of any manufacturers DI and non-DI engines you'll see that they are getting more benefits with valve control rather than fuel injection trickery. Another -ve is that the lean burn in most applications I've seen is not practical. In everyday driving it is difficult to keep the vehicle in this mode as any slight load increase causes a change back to stoich. So while the engine is capable of lean burn and greater fuel economy, the % of your commute that will fall under this mode will be very little.
lean burn works well in short runs and in traffic.
lean burn goes out the window after 110km
Not entirely accurate. Lean burn works well under constant speed and low load conditions or constant load conditions. I've driven my Stream on long stretches in lean-burn cycle on the hiway. This is only possible when traffic is light so I don't have to be slowing down and accelerating. It was actually developed to improve mileage on long runs. In traffic and below a certain speed even lean burn engines must run stoich. Traffic is much worse since the constant load changes cause the engine to switch out of lean burn.
More importantly to maximize the fuel economy capabilities of lean burn engines requires a change in your driving habits.
Re: GDI engines
Posted: September 8th, 2011, 2:04 pm
by ZeroOne
ek4ever wrote:ZeroOne wrote:ek4ever wrote:xtech wrote:GDI was very good tech......still is but more expensive 100 octain fuel an having to recirculate exhaust gasses to lower its NOX levels was its down-fall.........
Hyundai has brought the rights to this Tech and improved it with 21st century upgrades lets see how it runs
Not saying it isn't good technology, but it had specific requirements for it to be successful, low sulphur fuel and less dependency on EGR to meet emissions requirements. In fact had Mitsu used downstream NOX treatment and less EGR the outcome might have been better. As it is the issue is allowing consumers to think that this is just like non-DI engines so just use appropriate octane fuel and yuh good. Sadly that wasn't the case.
I think if you do a comparison of any manufacturers DI and non-DI engines you'll see that they are getting more benefits with valve control rather than fuel injection trickery. Another -ve is that the lean burn in most applications I've seen is not practical. In everyday driving it is difficult to keep the vehicle in this mode as any slight load increase causes a change back to stoich. So while the engine is capable of lean burn and greater fuel economy, the % of your commute that will fall under this mode will be very little.
lean burn works well in short runs and in traffic.
lean burn goes out the window after 110km
Not entirely accurate. Lean burn works well under constant speed and low load conditions or constant load conditions. I've driven my Stream on long stretches in lean-burn cycle on the hiway. This is only possible when traffic is light so I don't have to be slowing down and accelerating. It was actually developed to improve mileage on long runs. In traffic and below a certain speed even lean burn engines must run stoich. Traffic is much worse since the constant load changes cause the engine to switch out of lean burn.
More importantly to maximize the fuel economy capabilities of lean burn engines requires a change in your driving habits.
true but still a long north to south run doing less than 110km is impractical for the average driver.
If you drive below 110km on a long highway run good for you but the majority of people don't.
After 110km GDI goes out the window.
Re: GDI engines
Posted: September 14th, 2011, 9:47 pm
by loosemylife
My fule pump is goin in my lancer GDi i need to know where i can get one and most of all who installs those? HELP!!!!
Re: GDI engines
Posted: September 15th, 2011, 8:59 am
by TeamH2O
current everyday car is the purple/pink lancer for sale on 2nr right now, and it never has given trouble for 4 years, gdi. Injector service, plug change every 6 months, normal oil change etc. And it uses SUPER most of the times and works like a charm.
Key to these engines is maintenance and injector cleaning by removal as the tips build carbon.
Re: GDI engines
Posted: September 15th, 2011, 2:53 pm
by ZeroOne
haven't cleaned my injectors in a long while.....who cleaned yours?
removal is a pain
Re: GDI engines
Posted: September 19th, 2011, 1:18 am
by rollingstock
^ If you own a gdi i would advise you to do your own servicing, what needs to be done will never be undertaken by a mech, too labour intensive.
Taking out the injectors to clean is vital, sorry i never too pics but the intake manifold builds up a lot of carbon, last time i cleaned mines i started of by digging it out in clumps with a flat head screwdriver.
The egr valve also gets so dirty that it almost becomes clogged.
Tip: remove it, remove smaller components and clean separate, soak the intake in a strong degreaser and then spray out with a power washer and let dry, the intake itself is aluminium so it won't get corroded from water, get a thin cable and clean the air ducts in the vicinity of teh throttle body, this gets very dirty and causes erratic idle.
It is also a good idea to use an oil intended for diesel engines............yep for diesel engines, more detergents than an oil intended for gas engines, remember gdi is basically diesel tech, will also keep lifters from starting a racket won't stop it if already makes noise though.
Re: GDI engines
Posted: October 22nd, 2011, 3:33 pm
by squinty_eye
http://mitsubishi.epc-data.com/galant/ - English version for part numbers
http://mitsubishi.epcdata.ru/galant/ea1a/prgc/ - Russian site that shows u pictures of the parts so u can correlate
Got my mounts changed out by Fats in Maharaj St, San Juan, working good. Still have problems with accelerating. Rollingstock can you send pictures of how you cleaned out your intake assembly and injectors. I have mine since 2002 and I think it really needs a cleaning.
Re: GDI engines
Posted: October 22nd, 2011, 9:48 pm
by rollingstock
^ Sorry dude, didn't take pics.
It's not that hard though, just takes a while. The manifold is held in place by 3 bolts to the rear on a bracket, the bolts on top the engine and 2 bolts on the egr under the manifold, you need to remove the throttle body to get at the egr properly. There are coolant lines under the manifold so be careful with those.
The injector rail is easy to get to once the intake is removed.
Re: GDI engines
Posted: October 22nd, 2011, 11:59 pm
by xtech
block the EGR but leave it connected so it wont throw an ECU code......90% of the power robbing carbon soot inside the intake manifold and intake valves comes from there. Indeed about another 5% comes out of its crankcase breather sending oily air into the intake coking the valves. Easily fixed with a oil catch can.
Think of it like clogged arteries for your engines heart.........
when it becomes very bad valves stop moving and if your lucky your engine will sound like a
WRX.....stuck closed (hardly ever happens)
or
VW Bug....stuck open
some horror GDI pics
decarbonize, decarbonise [diːˈkɑːbəˌnaɪz]
vb
(Engineering / Automotive Engineering) (tr) to remove carbon from (the walls of the combustion chamber of an internal-combustion engine) Also decoke decarburize
decarbonization , decarbonisation n
decarbonizer , decarboniser n
4G9x GDI Engine before decarbonizing
Pistons



Clumps of greasy carbon build up everywhere..........stop this with oil catch can an shutting the EGR valve. Take not 4G93GDi-T drivers........imagine if your turbo leaking oil



Look at that........yes wonder why the engine dead........an low on power look how clogged these ports can get

GDI Injector can be seen in this one..........very dirty
So guys clean your engines........inside and not just outside
Re: GDI engines
Posted: October 24th, 2011, 3:01 pm
by bcozier
WOW!!!
Just bought a vehicle with 4g93t hav to do maintance right now...
btw i hav the tiptronic tranny, is this tranny as sensitive as the cvt??