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

After driving the car a lot for the past few days, I think we are back to our regularly scheduled programming. Car feels better than it has in months, and it's much more eager to go both around town and on the highway. The shaking and unsteadiness at highway speeds seems to be getting better as well. I am convinced that the rear caliper issue had a big part in the overall wonkiness of how it was driving; it had to be hanging up at times, because after replacing things and fixing that, it feels like I unleashed the thing. It just feels more free, if that makes any sense. 

All in all, it's back to being fun again. Hopefully, no more brake updates for a LONG time. 

Tony Sestito said:

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. 

So... This has happened again recently, but not as severe. This time, it was a slight dead spot in throttle after a gear change. I still can't consistently replicate it. I've been running 93 since the last incident, so I don't know if it's an octane thing, but I'm beginning to doubt it.

I've been thinking about it, and I'm wondering if it has something to do with the BPV. Right now, everything, save for the little charge pipe muffler and a K&N drop-in filter, is stock. I'm wondering if the BPV is recycling too much air for the intake and when it spikes, it cuts boost. I would assume this would throw a CEL, but maybe not. I've been thinking about doing a BPV bypass to vent to atmosphere instead to see if it helps. I know they make a $5 kit that caps off the BPV inlet and you get more turbo fun noises as a side effect. I haven't seen any adverse affects, and it's 100% reversible. Of course, all of this may be an really dumb theory. 

Any thoughts? 

Well, after researching extensively and seeing zero negative impact on doing this, I plunked down a couple bucks at Home Depot and used a zip tie I had laying around to bypass the BPV.



Home Depot Mods FTW.

I took it for a ride to run some lunch errands today, and I swear the thing runs better now. Seems to be happier when shifting between gears. Plus, PSSSSSST sounds on a turbo car are always fun. We'll see how it holds up or how it impacts anything. It's reversible in about 30 seconds, since the BPV tube sits below the intake elbow. Only thing I would do different is get the 1" chair leg caps instead for an easier fit. 

In reply to Tony Sestito :

I've been meaning to try this

Did it on day 1. (Had already done it on the 2017 Elantra Sport)

After a few days of driving... and I don't know how this is possible... but I swear the car is WAY happier. It feels stronger when building boost, and I haven't had any of the weird shift hiccups I had been having where it felt like it would cut throttle. Still going to keep an eye on things, but I'm liking this! 

One thing that has still been slightly annoying is a front wheel vibration on the highway between 70-80mph. It doesn't do it all the time, and it seems to go away when turning, but it is still annoying. It's not the brakes this time, either, as braking from speed is still very smooth with zero pulsation. I'll rotate the tires at the next oil change to see if that vibration moves from the front to the back.

I have also noticed that fuel mileage has gone up from 25-27mpg per tank to 28-30mpg after doing the brakes again. Helps to not have a dragging caliper, I suppose. And that's mostly sitting in bumper-to-bumper traffic, too. Not bad!  

I put one of these on the car and I love it!  Really wakes up the handling.  I did a 19mm on the Elantra touring when I had it; this one is a 22 and it feels great.  I believe the OE bar is a 17mm.  For under $200 and about 45 min in the driveway--highly recommended 

Whiteline Raer Sway Bar

In reply to FSP_ZX2 :

Noted! That said, I think this car already handles really great. It's one of the better handling FWD cars I've driven. 

This past weekend marked 4 years since I bought this car. I've amassed 54k miles in that time. Some additional stats:

-Spent about $8400 in "running costs" (fuel, maintenance, etc)
-I've averaged about 27mpg, with the worst tank at 22.4 and the best at 34.8. I expect that average to go up, as a good chunk of those miles were with a dragging rear caliper.

I've done all the maintenance myself so far. It's easy to work on and the service intervals aren't anything crazy or intrusive. Figured I'd go through a quick Good/Bad about the car so far. 

The Good:
-Still really fun to drive
-Still looks good
-It's just the right amount of rowdy without being annoying
-Efficient and handles extremely well for a FWD car
-Lots of room/storage and comfortable to sit in
-Efficient for what it is

The Bad:
-Thin paint
-Driver's seat bottom outer bolster is pummeled into oblivion and cracked/torn
-Driver's window switch auto up/down doesn't always want to work and constantly needs to be reset (lower window all the way and raise all the way to restore functionality)
-Steering wheel Kia emblem delaminating
-Everyone thinks the high beams are on when I drive at night due to the headlight design, so I get constantly bombarded with brights
-Dealer network is awful
-Aftermarket parts are there, but offerings are limited compared to the competition

So yeah, it hasn't been a perfect experience, but I went into this expecting less than perfection because Kia. I know they have their fans (especially on here) but my personal experience with Kia/Hyundai has been extremely hit or miss. I would say that this is way more in the "hit" column than the latter; the issues I have had are minor and can happen on just about any car out there. 

Would I recommend one of these to someone looking for a fun daily driver? Yes. I would at least take one out for a test drive and see if you like it, especially if you can find one on the cheap. New, I was able to get this thing for $7000 cheaper than the equivalent 2020 Civic Si or Jetta GLI, and it's been every bit as fun and reliable as one of those, if not more. It doesn't have a LSD, the fancy dampers, or the caché, but I can't think of a scenario where I've missed that in the past 4 years of driving. And I think it looks better than either of those, to boot. 

Kia discontinued the Forte and replaced it with the K4 for 2025, and out with it went this GT package. They now offer a "GT Line" which has the newer version of this engine that's in the Elantra N-Line, and it is not only down 21hp, it also loses the manual option. They did keep the multi-link IRS underpinnings, at least. The price is also going to be about $12k more than I paid for mine, due to the insane cost of cars these days. At that price, I would go Jetta GLI over the GT-Line or just pay a little more for the Elantra N which makes nearly 100hp more. 

Let's see how far we can go with this thing! 

I was bummed with the discontinuation of these. IMO, these are a hidden gem. $4k less than the base Civic Si, but with all the goodies if the higher trim. Comfortable, efficient, fun. 

In reply to bobzilla :

Kia has nothing in their lineup now that remotely interests me (or many other enthusiasts) with the departure of the Forte GT and the Stinger. That doesn't look like it will change in the future, either. It's unfortunate, because they really hit on something with those cars. 

In reply to Tony Sestito :

agreed. They were some of the last manufacturers offering fun cars people WANTED to drive at reasonable (sub $30k OTD) prices. Checked the current cost of the Civic Si and the last of the Forte GT Manual. It's over $5k difference now. 

I just parted ways with my 21 Forte GT. I have to admit I was very hesitant about the Forte, growing up my family was pretty diehard GM and getting a Kia felt like a roll of the dice. I put 104k trouble free miles on my GT with the DTC. I moved over to a GTI with a stick and so far im pretty happy. 

In reply to Tony Sestito :

My Stinger GT was a properly quick and fast car!  Had it not been for the oddly tiny footwells for rear seat passengers i would likely still own it.  Glad to see the FGT is still treating you well.

The car is due for its next oil change this weekend, and guess what? The brake issues may be back again, so I may be pulling things apart yet again while I'm working on it. I've noticed a drop in gas mileage again and the car has a hint of pulsation when coming down from highway speeds. This is getting really frustrating at this point. 

On top of that, my commute has been extra terrible lately; they have one of the commuter train lines completely closed for maintenance for a few months, so a lot of people have been driving into the city. Spending about 4 hours a day in the car 4 days a week is not very fun. Hoping I can solve this issue with the brakes once and for all, because it's compounding the annoyance of the commute. 

Over the weekend, I tackled an oil change, tire rotation, and a brake check at 55k miles. Oil change and tire rotation went as expected, but man, the brakes on this car... I've never dealt with stuck caliper slides more on anything. Last time, it was the rear driver's side, and now it was the rear passenger side. 





When I did the brakes recently, I checked all the pads for movement in the bracket and clearanced the ears a little to make sure they didn't stick. I also checked all of the slides to see if they moved, and they did. What I didn't do is take all the pins out, clean the slide bores, and use a purpose-built synthetic brake grease when I put them back together. I usually just check and see if things are moving, and if they do, I send it. But from now on, I'll be pulling everything apart and cleaning/regreasing everything. 

Weird part is that Kia seems to have used two different types of grease on the slides. There's the usual black stuff, and then there's this:



This grease is more orange, and what ends up happening is it gets hard and clogs the bore. My guess is that it's not as heat resistant as the black stuff. I had to peel this off this pin and the boot, and then take a wire wheel to the pin to get it back to bare metal. This was used on one pin in the back on each caliper and the black stuff was on the other pin. I've never seen that before on any car, so I'm chalking this up to an assembly error at the factory; maybe they ran out of the good stuff and used whatever was lying around to get the car down the line. Either way, after cleaning all of the pins and bores and using a synthetic brake caliper grease on all the pins, everything moves freely as it should. 

After a test drive, I found that the brakes felt a lot better and after the tire rotation, the front end vibration was gone. Hopefully that will be the end of the brake issues, but I've said that a few times now. Here's hoping! 

One week later...

I think I have this issue finally solved. The car has been way better to drive since doing all of this. I've also been reveling in the return of "Turbo Season". It feels like the car has about 50 extra hp on these crispy Fall mornings! 

On New Year's Eve, I performed the 60k mile service, which consisted of an oil change, checking the air filter, inspecting the fluids and drive belt, and replacing the cabin air filter. I also gave the car a bath and fully cleaned the interior (including upholstery cleaning), which I haven't fully done in about a year. 



The Castrol Edge Euro 5W30 oil I like to run in this car proved difficult to find this time around. Amazon had one bottle in stock for a staggering $130 and most other stores around were out of stock. I stumbled upon this 5qt bottle at one of the local Walmart stores for the normal price, and it was the last one. Not sure what's up with that, but I hope it remains available, because the car loves this stuff. Speaking of which, the car still doesn't burn or use any oil, which is good. It still looked somewhat clean coming out of the car. 



Air filter wasn't too gross, so I knocked out the leaves, brushed off the gunk, and tossed it back in. I may clean/oil it at 100k. I always read that these work better when they were dirty, which I never understood, but it wasn't dirty enough to do that just yet. 



While under the car looking at the drive belt, I noticed this piece of foam sticking out near the lower radiator hose. I yanked on it and all of this came out. This is not the first time I've pulled random foam out from the engine bay. Guessing it was under the radiator. Weird. 



The cabin air filter wasn't as gross as I've seen some, but with 20k on it and things getting stinky in the HVAC as of late, it was time to replace it. Kia says to replace every 15k, but 20k sounds more reasonable to me. 



Quick check on the interior wear and tear... and yeah, this driver's seat just keeps getting worse. I now have this hole, which I need to sew up before it really gets bad. 



This weatherstripping isn't doing too well, either. 



New to the early failure party are all of the exterior window sweeps. They are all dry rotting, and this one on the driver's door is missing a chunk. It's weird that my 45 year old Dodge pickup truck has better weatherstripping than my not-quite 5 year old Kia does, but that's the reality of things. This is dumb. 



I also swapped on my winter wheels a couple weeks ago. I really meant to paint them during the offseason, but with all the other chaos in my life over the last year, I didn't have time. I will punt that task to the spring, when I pull them off the car. 

Other than the trim issues, the car has been solid and has been a trooper dealing with the terrible abuse I put it through. The BPV bypass and running 93 octane seemed to eliminate all the weird hesitation issues I was having as well, which is great. I calculated that I put about 19k miles on the car commuting into the city 4x a week. That's an improvement from the 26k/year I used to put on my Mazda when I had it. The front brake pulsation is back with a vengeance, but I confirmed the rear calipers are still free and moving, so it must be damage from before I discovered that they were frozen again. I've decided to ignore this and just deal with it for now. The "National Mod" may happen later this year to fix that. 

Onward into 2025! 

Another slightly annoying thing I forgot to add that has bubbled up: the auto-down on the driver's door window works intermittently now. If I raise the window all the way up, it resets itself and works. I know a lot of cars (including my old Mazda3) have a function for the switch that makes you raise the window all the way and hold the switch for a few seconds to reset the motors positioning for the auto down feature after a power loss (like disconnecting the battery) but I am thinking this is a faulty switch. Again, more of a minor annoyance, but it would be cool if I could find an easy fix. 

what trans fluid have you used? Just passed 20k and it looks like they changed the fluid specs from the older manual trans to 70W. 

bobzilla said:

what trans fluid have you used? Just passed 20k and it looks like they changed the fluid specs from the older manual trans to 70W. 

I used Redline MT-85 (equivalent to a GL-4 75W85), but that was based on some bad/old info. I guess some of the older transaxles in the older Fortes and other Hyundai/Kia products used it, and it meets all the specs since it's a GL-4 fluid, but Redline MT-LV is the one you want to use with the revised specs. That said, the MT-85 has been fine. It's a bit thicker than the LV, but it does work.

From what I read, the 85 is actually better for people that see "severe use", but not recommended for colder climates. That said, I live in MA and it's been fine even on below zero days. I remember in my old WRX's that the transmission fluid would turn to heavy sludge in the colder weather, but this stuff has not done that at all. I would consider my commute "severe use", so even though it's technically the wrong fluid, I've been fine. I'll probably try the MT-LV at my next change. 

In reply to Tony Sestito :

I use the MT-85 in Rio and change it every year. It sees quite a bit of track time so I don't mind wasting a little money on it. Forte gets babied and doesn't see abuse or hard use at all but I'll still follow my normal trans fluid change every 30k with it.