I don't notice any knocking noise, could it be the brand of gasoline you are using? Have the dealer check it out, it might be a problem.

 

Sales guy told me it was normal. he said that you could take the cover off and actually turn off the pump somehow and it would stop making the ticking noise for a few seconds before it died.

 

All direct injected engines have the ticking sound, it is a small fuel pump at the fuel rail that supplies the fuel to the cylinders.

 

when i test drove both the regular EX, and then the SX Turbo, i noticed some slight ticking at first at startup, but then it went away within a few seconds and it was nice and quite but like everyone else is saying, the KIA guys also told me that is perfectly normal. as for the knocking, sorry, but i never encountered that yet, and hopefully never would. oh and some more noises, the exhaust note on the Turbo-GDI is very nice. it doesn't sound as zippy as a 4 banger usually sounds, it's actually got some throatiness like my Acura TL Type-S has, btw, gettin a Corsa Blue SX soon , i like this new Gasoline Direct Injection engine, very good KIA!

 

You're in good company. My Audi A4 2.0T made the same noise -- very much like a diesel -- at idle. It's the direct injection.

 

You're in good company. My Audi A4 2.0T made the same noise -- very much like a diesel -- at idle. It's the direct injection.

That's good to know as my LX does that ticking when the engine is cold.

Thought maybe the original factory crankcase oil was due for a change. Just have 1,800 miles on the original factory oil. I was planning on changing it at 3k, as I do all my regular oil change intervals.

Didn't know that GDI engines have that typical sound.

Thanks for the reassuring post.

 

Direct injection sounds like a sewing machine. I had DI in my 2.0T VW. Hated the noise myself. It is much more efficient.

 

GDI is Like A Diesel Engine

What you hear is normal for a Gasoline Direct injection (GDI) engine.

A GDI engine is almost identical to a Diesel engine. Both have high compression ratios. But instead of diesel, gasoline is injected under high pressure into the combustion chamber of each cylinder rather than the intake port in a fuel injection system. The result is reduced fuel consumption and emissions, especially when the engine is cold. Increased power output is also a result.

The Kia 2.4-liter four-cylinder GDI Theta II engine has a compression ratio of 11:3:1. A high-pressure fuel pump sends fuel to the injectors and helps bring output to ~200 hp and ~184 lb-ft of torque. Compared with a conventional engine of the same size, the GDI Theta II delivers 7 percent more torque on the low end, 12 percent more at the high end and as much as 10 percent better fuel economy.

Other engine features include a three-stage variable induction system that helps create an optimal air-to-fuel mix as well as Dual Continuously Variable Valve Timing to improve engine breathing. A lightweight crankshaft and catalytic converter also eliminate some weight to further increase the four-cylinder's fuel economy.

The power and fuel savings are even more impressive when a turbo is added to the mix.

Check out this video on Hyundai's version of the engine (which is probably the same engine with different branding).

Regards,

JC

 

Great post ... I heard the ticking in the videos that I have watched but this explains it ...!

 

Thanks JC (TE2) for the great info, this will make me less worry about my car. I wish KIA could insulate the sound better.

 

What they do not tell you is direct injection often leads to coking of the intake/exhaust valves. The invaluable cleaning gas that is often advertised is rendured useless information because the gas no longer flows over your intake valves cleaning them. Throw in hotter operating temps of the turbo and you have a mix for coking of the valves.


Keep the PVC(positive crank case system clean and operable)

The GDI is noisy because of the high pressure injection. Interesting to notethat the high pressure fuel pump that is run off a cam lobe looks to have a roller that contacts the lob. A solid cam follower is not the best for this as VW found out the hard way...along with soft cams...

 

yes it does have a different sounds for the GDI but hey if it works, so be it!

What I do notice is upon initial start in the garage is a rattle (small) from probably a heat shield or such for a few seconds and then goes away (probably warms just enough) but I am not concerned as that is the last time i will hear it under the next morning.

 

Here is the best video of direct injection and the sound it makes I have found. This is the VW FSI set up but the application for both cars are the same. Direct injection with a high pressure fuel pump. I believe the HP fuel pump pushes about 1200lbs per square inch. Don't quote me on that. Anyway, you will see and hear from the video what is going on. To me it sounds like a sewing machine on steroids. To others it sounds like a diesel.

APR FSI Injector Test Stand on Vimeo

 

I think the "rattling" sound is the injectors... I know on the VW 2.0T, upon startup, it would double inject fuel to light the catalyst quickly and made a very different sound only until it went through the warmup...

 

Can you find something showing the VW 2.0T double injects fuel to 'light' the catalyst quickly?

The injectors are noisy no matter cold start or warmed up. I owned the VW 2.0T Passat. Yesterday I sat next to a Chevy Eqinox with DI. Sounded like a sewing machine. DI is a great design in some respects such as better power and cleaner emissions but it is also noisy and coking of the intake valves is usually present after some amount of miles. Ported fuel injections would clean your intake valve as it passed over the valve into the combustion chamber. DI removes that cleansing effect of the intake valve.

 

Interesting concept for warming the engine quickly. I'm familiar with the 2.0T in the 06 Passat. More familiar than I care for to be honest. Pile of rubbish. Safest car on the road because it was always in the shop.....

 

Yeah VW took a few years to work out a lot of the problems with their 2.0T engine. The FSI engine from 2006 to 2009 had a bunch of issues that they improved on in the TFSI engine that they use currently. The original had issues with the high pressure fuel pump wearing out, the PCV system leaking boost, the diverter valve blowing out and leaking boost, a timing belt instead of chain... etc...
I had my VW in the shop A LOT too!!! That's why I decided to get rid of it after it was out of warranty...

 

LOL...here is my list for the FSI:

Intake cam
HPFP follower
HPFP
trunk latch
transmission hard shift 2nd gear
Leaking antifreeze...flange
Fried igniton coil..the day I purchased it!

That was just in 12 months!

I got extended warranty paperwork out the whazoo...which is nice however being on a first name basis with the service manager and having the shop on speed dial is not worth it. Dumped it and purchased the 2010 Optima. I was very tempted to get the 2011 Optima but being it is the first year redesign and I just came off the 2006 Passat first year redesign which by all standards was a failure I did not want to be the beta tester for the 2011 Optima KIA. Besides, I got the fully loaded EX for a song.

I can see you understand my pain when I'm talking VW!!!

 

so I have a EX GDI and i think i hear a slight knocking sound after I turn off the car it last for a little bit then goes away is this normal too?

 

I get a bad rattle when my car starts when it is colder out side. It revs high and rattles. Kia says this is normal for a GDI turbo. But it is a timing issue with the start up warming feature in the computer because all you have to do is hit the gas peddle and rev the engine and this changes the computer and fixes it immidiatly. So far Kia says there is no update to fix it. My car also pulls left over 60mph especially in the fast lane of the highway. Kia tried to fix it and it helped a little but its not fixed. Other than these two things my car runs great. BTW this is not the same thing as when you rev you engine high and you hear a high pitch metalic sound. That is normal GDI turbo sound

If you have the turbo make sure you get Mobile 5x40 turbo synthetic oil and the Mobile synthetic filter. You can get 5 quarts and filter on special usually between $30-$40. Take it some where and have them put it in for you and it will be $15-$20. You can go 10k to 15k miles on this and it runs way better. I did it after the first 1k miles then i changed the oil again after 8k miles and the oil came out of the engine and look brand new. My next oil change will be 18k miles and if it looks new then as well I will go 12500 miles and so on. In the long run this will save you alot of money in oil changes and maintenence

Also only put 92+ octane feul in from one of these gas stations only http://www.toptiergas.com/retailers.html

If you do both these things then it will help alot

 

Sorry to say, but running 92 is a waste of money, all octane does is control the propensity of the fuel to pre-ignite.
As for the oil change intervals, I agree with crystalworks...you should follow the mfg schedule exclusively.
I buy my synth wherever I can find it cheapest (I use Penzoil Ultra), and let the dealer change the oil and use a genuine KIA filter....costs me $17.

 

^Doing that will give the dealer the opportunity to say you have voided your warranty by exceeding oil change intervals.

I don't doubt that oil is good, just that you should change it every 5000 miles (SX) or whatever interval you have for the EX, LX, and hybrids.

 

Although the car is designed to run on 87, it may adjust for 92 (premium) resulting in better performance. However, i'm not entirely convinced the cleansing benefits of the additional detergents will really be applicable in a GDI type engine since fuel is injected directly into the cylinder, and not an intake manifold or throttle body.

Next long trip I take, I'll try a tankful of 92 to see how the car runs, and if there is noticeable performance or mpg improvement.

On my 2 wheeled toy, they recommend 89, but I run premium because of intake/exhaust modifications, and more importantly more advance in the timing.

 

Again, NO...there is no adjustment, it does NOT improve performance!
The only place a higher octane would be helpful is if outside ambient air temps are so high (100 degrees+) to be causing pre detonation.

Let me say this again....higher octane does not give you more performance, or improved gas mileage, ESP in these engines.

If you don't believe me, look up octane in a web browser, and see what it's purpose is.

 

Any adjustment would be made by the ecu. My camaro required premium, but ran just fine on 87 if you weren't hammering on it. Mileage was down 1-2 mpg's too. On regular, the car just didn't seem as peppy as on 93. The whole benefit of premium was more ignition advance, thus more power. Surely these 2011 vehicles have knock sensors in them. OTOH, if the [stock] software can't take advantage of this, then as you say, there is no gain. However, once the stock software is modified, i'm sure there will be benefits to running premium.

 

I don't believe it is a ecu adjustment at all. High compression creates more heat and a environment inside the piston chamber that is enough to pre-ignite 89 octane fuel. High octane was developed during WW2 to handle radial engines on Corsairs/Hellcats with very high compression engines. This GDI engine of KIA is low compression and does not require the high octane.

 

There is ABSOLUTELY NO BENEFIT to using a higher octane than your engine needs. The only benefit is increased profits to the oil companies that have cleverly convinced some of the public that their new "Super-Duper, Premium-High-Test, Clean-Burning, Used-By-Famous-Racing-Types-All-Around-The-World, Extra-Detergent-Laden-Keep-Your-Pipes-Clean, Extra-High-Octane" fuel is your engines’ best friend.

High Octane

 

Hello, I'm new here, just picked up an EX GDI 11 last night. Out of curiosity, is this an interference engine? In looking at the Hyundai video, it certainly looks like one, but at least it has a timing chain instead of a belt.

 

No, it's not.

 

Glad to see i'm not the only one that has noticed the noise. I have a 2011 Optima, Tho I believe i have a lemon and i am fighting right now to get a replacement car. At 66 miles i drove my car off the lot and made it home before the check engine light came on for the first time, took it back the next morning and they said they fixed it, drove it off the lot again to get the check engine light, then they decided it was a sensor in the transmission..didn't fix the problem so they replaced the trasmission, torque converter. then 2k miles later my shifter started to stick in park and they replaced the shifter with the break switch. 2k miles after those replacements i have it back in the shop yet again because the shifter is sticking and the cruise has stopped working and my Average MPG goes from 99.9 to 11 and then back up to 67.3...the shops says the break switch has gone out again and now the fuel system senser is bad....we got rid of my 03 olds alero to get me a new car so i wouldn't have any problems since my husband was deploying to Afghanistan for a year while i am in Colorado with no family or an extra car with our 1yr old....My car has been in the shop for 20 days so far and i've owned it 4 months....they refuse to give me a rental car and told me to come pick up my car and wait a week for replacement parts...the best part is sometimes i don't have break lights because of the sensor being bad and they want me to drive around with my 1yr old in the car this way.....I have called kia directly and the lady i talked to told me well we are fixing it aren't we.......my husband is fighting for our freedom and instead of concentrating on staying alive and safe he's worried about his family at home being in an unsafe car! Thanks Kia

 

I am very sorry to hear that. If you haven't contacted the attorney general in your state, or your senator, I'd write them a letter. If Kia is giving you a hard time, I'd give it right back...in spades. I know it's hard work, but I wouldn't put up with that kind of bs.
This has to be the worst experience I've yet heard about. You have my support.

 

I noticed it is a bit loud when started in the cold too. I did some reading on GDI technology and found that it is normal. There is nothing clanking around in there, it just takes a LOT of computer assistance for a GDI to run smoothly, especially when cold.

It would be cool if the Optima had an in-line 6cyl, like a BMW 3-series. They are sooooo smoooth. (Wishful thinking).

 

It would be cool if the Optima had an in-line 6cyl, like a BMW 3-series. They are sooooo smoooth. (Wishful thinking).

But the latest BMW engine is a turbo 4 and it performs well and is very economical (36 highway). I have 2 friends with inline 6 BMW and they are very smooth but not that economical.