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2013 NAV manual
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Discussion Starter · #1 ·
I've been trying to figure this out for over a year now, and at this point I'm about to just get rid of this trash ass car if I can't fix it. About a year ago I noticed my car decided that when it get to it's normal operating temperature, my idle rpms sit at around 600 and dip to 300 if I move the wheel, and when driving it, it accelerates really sluggishly, especially on inclines where if I'm not careful, I'll stall when I try to put it in gear. This is a 13 manual base btw. I have tried to find a solution for this problem for so long that honestly I have no idea what to do anymore. Sometimes I'll have to damn near floor the accelerator just to put it in gear. I cannot for the life of me figure this out and it's making me incredibly frustrated. I drove a toyota camry recently which has similar horsepower and my car made that one look like a sports car. There doesn't seem to be any leaks, the spark plugs are brand new, the air filter is brand new. I have no idea what to do with this car.
 

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-Manual base, Turbo or NA?

-Mileage?

-Any Modifications? Tune especially?

-Throwing a Check Engine Light? Can you pull the codes if so?

-What oil and filter are you using, and what interval for changes? (Should be 5w-30/5w-40/0w40 Full Synthetic every 3k miles with an OEM filter)

-Have you ever had the transmission serviced? Supposed to be a closed system but if you drive hard a fluid change is recommended every 80k miles at most. Problem could be here.

-What's the throttle response and idle like in Neutral? If it responds normally you're probably looking at a transmission issue.

-What about cold startup and cold idle? Does the car accelerate like normal? What temp does idle start to drop?

-Are all intake clamps and hoses properly secured, especially if turbo?

-Making any strange noises, especially on acceleration?
 

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Discussion Starter · #3 ·
-Manual base, Turbo or NA?

-Mileage?

-Any Modifications? Tune especially?

-Throwing a Check Engine Light? Can you pull the codes if so?

-What oil and filter are you using, and what interval for changes? (Should be 5w-30/5w-40/0w40 Full Synthetic every 3k miles with an OEM filter)

-Have you ever had the transmission serviced? Supposed to be a closed system but if you drive hard a fluid change is recommended every 80k miles at most. Problem could be here.

-What's the throttle response and idle like in Neutral? If it responds normally you're probably looking at a transmission issue.

-What about cold startup and cold idle? Does the car accelerate like normal? What temp does idle start to drop?

-Are all intake clamps and hoses properly secured, especially if turbo?

-Making any strange noises, especially on acceleration?
- NA

- ~138,000 miles

- New amp, sub and a high output alt have been installed.

- No check engine lights

- Full synthetic 5w-30. STP filter. Have put less than 1000 miles on it since last change. Regularly serviced around 3-4k miles. I periodically check the oil level.

- Transmission has not been serviced since I got it (about 32k miles ago)

-Throttle response seems fine. However in neutral the car shakes a bit if I accelerate to 2000rpms. No shakes above or under 2k, not sure if that's normal or not. Idle isn't rough but gets a bit rumbly when I have the air/AC on low. Idle speed is lower than it used to be (700-800ish if I remember correctly): ~620rpms now. It jumps to 850rpms when the AC is on full blast, but I figure that's normal.

- The car starts up fine when cold. Idle is about 800-900 rpms (higher if it's cold out of course). Car accelerates normally and shifts smoothly until the temperature gauge hits the middle mark (about 190F I believe). Problems begin when the temp get to about that much.

- I actually checked the clamps earlier today and they're all properly secured.

- No strange noises at all, though when it's warm the engine sounds a bit louder.
 

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2014 VT manual
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Hmmm what plugs and gap ?


Has the clutch system ever been bled.
 

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Ever changed your pcv valve?
STP filter needs to go and get a stock OEM filter designed for the car. 🤦‍♂️

How's your battery and voltage? New battery or still the original?

There's a ton of variables here and that's why we are asking the questions to hopefully get you going.
Like was said earlier the plugs have to be gapped even if their so called pre-gapped.

Still on the same ignition coils?
Check the grounds in the car in the engine bay to make sure the paint has been removed from the ground point and properly cleaned.
 

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Discussion Starter · #7 ·
Ever changed your pcv valve?
STP filter needs to go and get a stock OEM filter designed for the car. 🤦‍♂️

How's your battery and voltage? New battery or still the original?

There's a ton of variables here and that's why we are asking the questions to hopefully get you going.
Like was said earlier the plugs have to be gapped even if their so called pre-gapped.

Still on the same ignition coils?
Check the grounds in the car in the engine bay to make sure the paint has been removed from the ground point and properly cleaned.
No I appreciate all the questions. I want to get to the bottom of this. PCV valve was replaced in March. Battery and voltage is fine. Battery is about a year old at this point. I checked the spark plug gaps before I installed them. They seemed fine, though two looked a little too narrow. Widened them but then I started getting that skipping feeling (not sure how to properly describe it) when I would accelerate. Narrowed them a little bit and it's been accelerating fine since. The original issue started well before this so I don't think that's the problem. All the grounds I could find have been sanded and cleaned. Still the same ignition coils, but I checked them with a voltmeter and they're giving the proper readings. I can get a new filter for the car, but maybe I should wait until I have to change the oil again? Out of curiosity what's wrong with the STP filters?
 

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The first things I would do from here are replacing the trans fluid, checking plug gaps, and cleaning up your engine grounds. All are cheap, easy basic maintenance items and all three can be done in less than four hours total and will help narrow things down greatly. If you're really on a time crunch, personally I'd do the trans fluid first. You never know what happened to the car under other owners and it's always good to know what kind of fluids are going into your car.

That shaking you mentioned happens more like a rattle to me at about 2.5k RPM (13 Turbo AT), vaguely remember it being something about harmonic frequencies in the engine. I wouldn't worry too much about it.
 

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It's my opinion that the spark plugs gapped to .040" is totally out of spec.
 

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It's my opinion that the spark plugs gapped to .040" is totally out of spec.
According to the service manual, the NA is gapped to .035-.039. This tracks with what I remember the differences being between the turbo and NA, but I suppose I don't know for sure.
134351
 

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Discussion Starter · #11 ·
The first things I would do from here are replacing the trans fluid, checking plug gaps, and cleaning up your engine grounds. All are cheap, easy basic maintenance items and all three can be done in less than four hours total and will help narrow things down greatly. If you're really on a time crunch, personally I'd do the trans fluid first. You never know what happened to the car under other owners and it's always good to know what kind of fluids are going into your car.

That shaking you mentioned happens more like a rattle to me at about 2.5k RPM (13 Turbo AT), vaguely remember it being something about harmonic frequencies in the engine. I wouldn't worry too much about it.
Thanks for your reply! I've heard a lot of conflicting info on replacing trans fluid, some saying that it's bad for the car in some way, which is why I never did it. Do you know anything about replacing that fluid harming my trans? I think I'll probably do it anyway, but I was worried about that. I'm pretty sure I have all the grounds sanded and cleaned, and I'll re-check the spark plug gaps again today. Are you aware of how many ground points this car has and their locations? I believe I've found six in total.
 

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According to the service manual, the NA is gapped to .035-.039. This tracks with what I remember the differences being between the turbo and NA, but I suppose I don't know for sure.
View attachment 134351
turbo is much less.... so this sounds right for NAV.
 
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Discussion Starter · #13 ·
According to the service manual, the NA is gapped to .035-.039. This tracks with what I remember the differences being between the turbo and NA, but I suppose I don't know for sure.
View attachment 134351
Yeah I checked the manual and saw this too. I think I have them properly gapped, but it couldn't hurt to check them again. I'll do that in a bit.
 

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Thanks for your reply! I've heard a lot of conflicting info on replacing trans fluid, some saying that it's bad for the car in some way, which is why I never did it. Do you know anything about replacing that fluid harming my trans? I think I'll probably do it anyway, but I was worried about that. I'm pretty sure I have all the grounds sanded and cleaned, and I'll re-check the spark plug gaps again today. Are you aware of how many ground points this car has and their locations? I believe I've found six in total.
Replacing the fluid on a manual gearbox is no different than changing your engine oil.
Use the MT-85 oil by Amsoil as this is one of the best I've read about for these transmissions.


It's my opinion that the spark plugs gapped to .040" is totally out of spec.
I tend to agree with this completely. Optimum range is BETWEEN what's recommended so readjust your gaps as needed. Use a wire gap tool instead of the cheap wheel gap tool.
This is the proper wire gap tool.
AEBF5225-8B8E-4811-ABBC-BE4DFAB7B89B.jpeg

Do not use these. Very inaccurate.
90DF3975-EBBC-4F11-93B3-72B434E9D045.jpeg
 

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It's generally accepted that the OEM Hyundai filters are what's best for this car. Pulling them apart has revealed they're apparently REALLY good for an OEM piece, aside from the fact that that's what's on from the factory, and thus won't void warranty. No reason not to, especially considering they're so cheap.

I changed my A/T fluid about 14k miles ago and have had no issues with it since. Definitely recommend it if for no other reason than peace of mind. I would also recommend you DON'T do what I do and spend four hours trying to find the fill cap because you were just so SURE you had a DCT and none of the videos you can find online for the DCT match what's on your car.

This is the thread for trdtoy's excellent guide on engine bay grounding. Note that manual trans grounding points are apparently slightly different, but a good guide to go off nonetheless.

For a little clarity, can you reiterate what the "original issue" you're trying to solve is at the moment? Is it still idling low, is it connected to turning the steering wheel like you said?
 

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Discussion Starter · #17 ·
It's generally accepted that the OEM Hyundai filters are what's best for this car. Pulling them apart has revealed they're apparently REALLY good for an OEM piece, aside from the fact that that's what's on from the factory, and thus won't void warranty. No reason not to, especially considering they're so cheap.

I changed my A/T fluid about 14k miles ago and have had no issues with it since. Definitely recommend it if for no other reason than peace of mind. I would also recommend you DON'T do what I do and spend four hours trying to find the fill cap because you were just so SURE you had a DCT and none of the videos you can find online for the DCT match what's on your car.

This is the thread for trdtoy's excellent guide on engine bay grounding. Note that manual trans grounding points are apparently slightly different, but a good guide to go off nonetheless.

For a little clarity, can you reiterate what the "original issue" you're trying to solve is at the moment? Is it still idling low, is it connected to turning the steering wheel like you said?
Lol okay good to know. I'll change the trans fluid asap and buy some OEM filters when I get paid. As for the grounds, I've seen that thread but I can't find the 4th, 5th, and 8th grounds pictured there. The original issue my car is having is that when my car warms up to operating temperature, my acceleration is super sluggish, at times if I'm on an incline I'll stall out trying to put it in gear. When the engine is cold, it drives as it normally should though. Also yes the idle speed is low, and drops to about 300rpms when I turn the wheel while idling.
 

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Discussion Starter · #18 ·

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Discussion Starter · #19 ·
Replacing the fluid on a manual gearbox is no different than changing your engine oil.
Use the MT-85 oil by Amsoil as this is one of the best I've read about for these transmissions.



I tend to agree with this completely. Optimum range is BETWEEN what's recommended so readjust your gaps as needed. Use a wire gap tool instead of the cheap wheel gap tool.
This is the proper wire gap tool.
View attachment 134352

Do not use these. Very inaccurate.
View attachment 134353
Okay. I have a wire gap tool so I'll check them in a little bit and report back when I can.
 

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And again, not throwing any codes/lights on the dash? It's worth connecting a reader even if there are no lights just to confirm there are no pending codes. I'd do this right after reproducing the issue just to make sure.

Have you ever routed in oil catch cans, and if so, how long ago? If not, are your PCV and valve cover ventilation still routed the stock orientation? (Valve cover to intake, PCV to throttle body)

Have you ever pulled the throttle body and intake manifold? Carbon and oil residue buildup can be a massive problem on these engines, especially without catch cans. If you're comfortable with it, I would recommend pulling both and cleaning them out. This will also allow you to inspect the intake valves to see carbon buildup on the valves and intake runners. If this is sufficiently built up, it could cause the trouble with your idle. The extra load from the power steering draw on the alternator is putting extra load on the crankshaft and slowing the engine, and air can't get into the engine fast enough to keep it running at the correct idle. This is another one of those "you'll probably be glad you did it anyway" even if it's not the root cause.



If there IS an excess of buildup (post pics pls), there are a couple of options. While the intake manifold and throttle body can be cleaned out pretty easily with detergent and water, your only real options for cleaning the intake valves are either a chemical cleaner or walnut blasting.

A chemical cleaner is the easier option, where you get a friend or tool to hold the throttle at ~2500 RPM while you spray it into the throttle body in bursts to keep from stalling. While I personally haven't had any issues with using a chemical cleaner, there are people on these forums like trdtoy (who knows far more about these engines than I do) who advise against using them. Additionally, they're not all that effective, especially compared to walnut blasting. That said, it may be enough to get you vehicle running better, and for less than $20.

Walnut blasting is much more effective, and much more expensive. It can be done yourself if you have an air compressor, media blaster (harbor freight has cheap ones), shopvac, something to spin the crank, and an adapter for our intake runners. You can also check if a shop can do it, but I would expect to pay a couple hundred bucks to have them do it.
 
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