2020 Kia Forte GT 6MT Maintenance/Build Thread: Into The Unknown

Quick post-plug change observation:

On my commute this morning, the car felt "snappier". It felt more willing to rev and ran smoother than it has in a while; idle and revving were getting choppier as of late. I also recently switched back to running 87 in it, since I've been commuting much more with my office making me come in more to save a few bucks, and between the plugs and the new brakes, the car drives like it's brand new again. This car responds to small changes like nothing else I've had. 

Just from doing the brakes, I've noticed a 2mpg increase per tank, so I'm hoping the plugs help with that as well. And yes, you read that right: the BRAKES helped mileage. There was definitely something hanging up there! 

In reply to Tony Sestito :

There's a reason actual "brake services" are good, and not the quickie lube "spray some brake cleaner on them and send it" version. I like to check them when I do tire rotations and if anything feels iffy, it comes apart and gets cleaned and relubed and put back together. 

Tony Sestito said:

I realized that the recommended service interval for a plug change on these is a weird 42k miles, so I set out to order a set, since I had 41k on the car. After doing some research, I found that the NGK Laser Iridium plugs (part # 97080) are the identical plug as the factory plugs. Only difference is the box they come in. That said, I ordered 4 of those from RockAuto and saved $25 over the parts counter. 

I read in places (mostly a Forte GT FB group I'm in) that this is a hard job and that there's all sorts of stuff in the way, removing the coils is difficult, etc. Not sure what's in their vapes, but this may have been the easiest plug change I have ever done. It was about 20 degrees out today, so I am very glad this was an easy one!





Pop the engine cover off, and you're presented with your typical coil-on-plug 4-cylinder engine setup. Only tools needed are a 10mm socket, a 5/8 spark plug socket, and an extension. One 10mm bolt per coil; remove those and the coils come out easily. 



This was the "hard part"; I had to slightly move this wiring harness and pipe out of the way to access the 10mm coil retention bolt. Oh man! 



When I said that these are the same plugs as the factory ones, I meant it. Same exact catalog numbers on the plugs and everything. I did notice little Hyundai emblems on the collars on the stock ones. The aftermarket NGKs did not have that. That and the box they come in are the only differences. 



Plugs looked like plugs with 42k miles on them. No areas of concern; they look pretty good. I honestly think they could go a lot longer, being iridium and everything, but I'm going by the book here. When I installed the new ones, I dabbed a little anti-seize on them so they come out easy down the road. 

BONUS: I also remembered it was about time for a cabin air filter. I think I went over how that's done earlier in the thread. 



Old one looked better than I thought it would, but I changed it anyway. 

Next up: Keep driving the thing! 

I think the 40K miles replacement of plugs is common with modern turbo motors.  My dad has a Mazda CX-5 and noticed the same kind of interval.  

I changed my plugs a few weeks ago.  No issues.  Changed the oil at the same time. I usually don't change the oil drain bolt unless needed.  It was very needed this time. Strange that it was fine for 9 or 10 oil changes and then all of a sudden started to leak.  

Also did the cabin filter.  The interval on that is 6000 miles or 12 months.  Mine was long overdue and it looked like it. 

I don't know if I mentioned when I put new winter tires on it.  Switched to Vredestein Wintrac Pro - 205/50R17. I put them on steel wheels for durability and less expense.  I love these tires for winter use.  They are great in rain and snow and more than decent in the dry.  

In reply to Msterbee :

If you look back in the thread, you'll see that I also had to change the drain bolt. Old one started leaking profusely somewhere around 35k miles. 

And I'm running the same size tires on a set of cosmetically challenged Drag DR34's in 17x7.5 wheels I picked up cheap last year. I forget the offset, but they are basically flush. I think a fresh coat of paint on these will go a long way. I'll do that next Fall. 

The tires are Michelin X-Ice Snows, and I'm really happy with them. I used them last season, but it never snowed! They got put to the test a few times this season so far, and they have been stellar. 

In reply to Msterbee :

I still do 30k intervals for plugs on all the Koreans. It's just easier to remember and replacing them after I do a seafoam is an easy button. Overkill? PRobably. 

bobzilla said:

In reply to Msterbee :

I still do 30k intervals for plugs on all the Koreans. It's just easier to remember and replacing them after I do a seafoam is an easy button. Overkill? PRobably. 

Considering mine was leaking around 40K, changing at 30K miles seems pretty reasonable. I've read before that they should be changed every oil change which is definitely way too often.  Then again, modern metallurgy may have rendered an old necessity moot. 

Tony Sestito said:

In reply to Msterbee :

If you look back in the thread, you'll see that I also had to change the drain bolt. Old one started leaking profusely somewhere around 35k miles. 

And I'm running the same size tires on a set of cosmetically challenged Drag DR34's in 17x7.5 wheels I picked up cheap last year. I forget the offset, but they are basically flush. I think a fresh coat of paint on these will go a long way. I'll do that next Fall. 

The tires are Michelin X-Ice Snows, and I'm really happy with them. I used them last season, but it never snowed! They got put to the test a few times this season so far, and they have been stellar. 

My dad worked for Michelin for 20 years.  I try to use their tire when I can but they don't make a tire that does what I want. Excellent in snow but still with some performance intent.  Tire Rack recommended what I bought and I'm glad they did.  My previous winter tires still have some life left in them.  Maybe 5000 miles.  Just not in snow and winter conditions.  I put them up on Craigslist but no bites.  I'm not on Facebook so Marketplace is unavailable for me. 

I have a really annoying problem starting to rear its ugly head with the stock sound system in my car. 

I posted here about thinking that a speaker was blown, but I'm not so sure this is the case after some testing. Depending on the song and stream quality/bit rate, it sounds like the stock speakers are either blown or maxing out, especially with the mids and bass. They sound muddy and unclear, and they are rattling in the doors/rear deck. But the funny thing is, it doesn't do it all the time. When it does do it, the worst offender of this is the driver's front door mid-range speaker. 

This morning, I was driving into work, and I opened the window a bit. Somehow, that made the noise go away. I put the window up and down a few times and noticed that the door panel flexes a bit when you do that, so I'm now thinking it's something loose in there that's causing the annoying sounds. Whatever the window regulator does seems to silence the resonance. The rear package tray also seems to rattle from the subwoofer as well; the fact that they just slapped a subwoofer up right against a basically bare metal package tray with a plastic tray on top without much sound deadening is a recipe for rattles.  

Wondering if it's worth getting some Dynamat or something similar on the doors/door panels and package tray. It's such a dumb thing, but it is driving me insane! 

In reply to Tony Sestito :

i did on the Rio. Helped a bit. It's already had it's speakers replaced but the factory sound deadening on it had hardened and fell off the inner panel. 

In reply to bobzilla :

I will have to scope out how easy it is to take off a door panel. I am guessing it's a giant PITA. I think I have some Killmat kicking around in the garage I can try slapping on here and there to see if it helps. 

In reply to Tony Sestito :

SUPER easy. Should be 3 screws, trim tools to pop the bottom out and then slide the door panel up off the ledge. Unplug the window and mirror switch and done. 

I have updates. 

I was messing around with some settings on the stereo, and I took a look at the Phone Projection settings under Volume. In other vehicles I've had, that will adjust the Bluetooth's "line-in" level, which essentially enhances the volume of the stereo. The higher the number here, the higher the volume output in the car when streaming music. It usually just scales the volume but doesn't cause the issues I'm having, but it was worth messing with. Or at least it didn't in my Mazda. 

I found that it had a value of about 25 of 50. I turned it down to 15, and that seemed to help the situation quite a bit. It's not 100% solved, but it's much better. I can actually give the EQ more bass now. 

Additionally, I found that different apps have different line level volumes. Spotify, for example, is vastly different than the MP3 music app I use called BlackPlayer EX. The volume on Spotify is lower, but the quality of sound on BlackPlayer EX is far superior and tends not to max out the speakers like Spotify does. 

I'll keep messing with it and with other apps/music sources to see what works best. I even ordered an interface cable for Ye Olde iPod Classic so I can try that. Somehow, Kia's infotainment system still supports it. 

More updates on the speaker thing:

I was visiting my parents over the weekend, and my nephew was there. He's big into car audio, so I got him in the car to see what he thought. He came up with the same conclusion: there's something up with that driver's door. We did some testing, and noticed that it was the same behavior as a few posts above: when I press on the door panel OR if I roll down the window, even partly, the noise goes away. That leads me to think that something in the door panel itself is loose and causing the noise. I'll have to pull that panel and see what's going on in there. 

He's also trying to convince me to add an amp and sub to the car. I know there are ways to do this and keep the factory stuff; common method is tapping power off the factory amp that's located right in the trunk. He even offered to donate a sub and box to the effort if I want to go that way, but we'll see. It's been over a decade since I've had a setup like that in a car. It would allow me to take stress off the mid-range speakers if I did that. 

Side note: did an oil change yesterday, and the car will hit 45k during my commute today. No evidence of burning oil, which is obviously great. The GDI cars have a reputation for this, but mine is still doing well. 

Any issues or maintenance related to top end build up in the intake ports with the GDI engine?

If I decide to get rid of the grand Cherokee I'm thinking of a new Forte GT as the replacement. 

In reply to No Time :

That's probably a Bobzilla question, since he's our resident expert on the Korean stuff, but I would assume it will need some sort of cleaning at some point in time like most other DI stuff. 

Might want to act quickly, because the new K4 (the Forte's replacement) debuts later this week, and I'm not confident there will be a GT version, at least for a while. 

Catch cans help these stay cleaner longer. But at some point you will need to do a top end clean. I still use seafoam on our GDI stuff, but as long as you use quality gas (top tier) its not much of a problem. 

I still need to put in a catch can on mine. Rio runs one. 

In reply to Tony Sestito :

Good to know. I need to figure out if I have a bad head gasket, and then decide if I've reached the point where I want to stop throwing money at the jeep. 

Yesterday, on the way home from work, I found myself in heavy traffic (surprise surprise). About 35min into my drive, I went to go from a stop, and the car started sputtering. It kept wanting to stall in gear, so I put it in neutral and tried again. Same thing. It felt like someone removed the turbo! Mashed the throttle and it started moving but with some clutch chatter like I wasn't giving it enough gas. I cycled the drive mode button a few times, which didn't seem to help, either. I couldn't pull over because I was in the middle lanes, so I had no choice but to stay in it. After about 30 seconds of this, it cleared up. No CEL at all, either.

The rest of the ride home, it was fine. I gave it the beans a few times when the traffic freed up, and it drove like it should. 

About a year ago, this would happen VERY briefly every once in a while; I'd be driving and throttle would cut like the signal between the pedal and throttle body was interrupted. I think after it did it then, I switched to 93 octane, and it stopped. A few months back, I switched back to 87 (the recommended octane, BTW) since I started driving the car a lot more. Guess I'll switch back to 93 and hope for the best. I mean, it has nearly new plugs and I've kept up with all the maintenance, so I have no idea what this could be. Bad cam position sensor maybe? Impossible to tell without a CEL. 

I don't trust the dealer to find the issue, since they have flat out refused all warranty issues I've brought up so far, and the fact that it's so intermittent it will be near impossible to replicate anyway. Wish I had a way to datalog with the stock ECU. 

Boost solenoid are not uncommon. 

In reply to bobzilla :

Boost Solenoid on the charge pipe, or the Wastegate Solenoid near the turbo? There's a drastic difference in price, yikes! Probably not a good idea to warm up the Parts Cannon until I can at least get a code. 

In reply to Tony Sestito :

Checking... you did scan it for stored codes right? I've had them without a CEL. 

EDIT: THIS ONE off the turbo on hte passenger side (at least on the 2020 Elantra GT)

In reply to bobzilla :

I didn't scan it, but I will. And that's the cheaper one. If I have to fire up the Parts Cannon, I'll get that one. 

Can you datalog with Torque Plus, and Android phone, and a bluetooth OBD2 dongle?  

In reply to dj06482 (Forum Supporter) :

I actually might be able to do that. I have all of those things! 

I used that setup tonight to confirm that it has zero stored codes. Everything looks normal. I also "tested boost" on a back road, and it's reading 16psi under full boost. Not sure what stock levels are supposed to be, but that seems healthy to me. Also topped it off with 93 octane again. We'll have to wait and see if it happens again. 

In reply to Tony Sestito :

It can have short peaks around 20psi (hard accel, right at a gear change), but 14-16 is the normal range you should see it. 22-up gets 16-18 and a tiny bit larger turbo.