Hyundai Forums banner

21 - 30 of 30 Posts

·
Registered
Joined
·
176 Posts
The misfire did not completely go away for me after changing spark plugs (gapped and torqued) and the coil packs. I started worrying about a vacuum leak causing the issue next. Tested it by spraying carb cleaner around some of the vacuum lines. Inspected the PCV valve (shook it and heard rattling inside meaning it was good still). I guessed brake booster, but wasn't willing to attempt that, so got an OEM brake booster vacuum line with the check valve between and hooked it up quick, but didn't seem to resolve my degrading power and fuel consumption now too. Last week, on the commute home with 1500 ft elevation incline in about 10 miles, my Elantra GT 2.0 was struggling to maintain 65-70 mph. Downshifting to 4th or 5th helped a tiny bit, but the steepest part had me down to 60 mph, not great when others are passing at 75-80. Everytime I accelerated up through the gears the engine bay gave this whistling noise above 2500RPM and ONLY when accelerator was pressed. Let off of the gas, noise went away. Bad vacuum leak? Slipping belt? Loose pulley? Hyundai dealer says it needs a new engine, reporting they found debris in the oil. Same thing all the older Hyundai recalls were for...at 85K miles 2nd owner, I'm out of powertrain warranty, but dealer created case with Hyundai to see if anything can be done to help with the dealers quote of $12K to replace engine with short block since long blocks are unavailable. I have been looking to get a Veloster N as my next car, but after this, won't be coming back to Hyundai...
Dude. Your story mirrors mine. Same screeching noise, same everything.

Trade it in. Not for a Hyundai or Kia.
 

·
Registered
2016 Elantra GT 2.0 AT & 2011 Sonata SE 2.4
Joined
·
16 Posts
Dude. Your story mirrors mine. Same screeching noise, same everything.

Trade it in. Not for a Hyundai or Kia.
I almost did a few months ago. I test drove a Veloster N and fell in love with it. I was too hesitant and ended up getting burned by this issue. Looking at Toyota Corolla Hatchbacks now...getting off topic lol Should go scope out the Toyota forums, eh? Lol
 

·
Registered
Joined
·
852 Posts
After initially loosening the fuel pump, I was able to get the coil pack out to change the plug. Core issue was random misfire in Cyl 1&4. Turns out new plugs did not fix it, so ended up getting new coil packs. Going to remove the coil pack the second time, I was able to wiggle the pack out and place the new one in without messing with fuel pump at all...so cool!
Before changing the coil pack. Inspect your coil boots and spark-plug spring connector. If the boots are worn, brown track and moisture got in, the spark-plug spring connector can corrode. The two boots and spark-plug spring connector will fail before the spark-plug or coils.

Go to www.RockAuto.com and find the coil boots/spark-plug spring kit. The A/C Delco kits are $3 per plug. Get some high temp. Silicone Dielectric Grease for the boots.

Do not use regular grease on the boots. They will carbon up and cause shorts or misfire.

I know Hyundai do not recommend using anti-seize. I use a very light blush of Nickel anti-seize, to prevent corrosion and improve conductivity. Brush off any corrosion from spark-plug threads. Brush off any corrosion from the coil lock-down bolt and use a light blush of Nickel anti-seize on the coil hold down bolt to promote grounding.

Do not use Zinc or Copper anti-seize. Zinc and Copper will form a low temperature alloy and fuse the spark-plug to the Aluminum heads.

Try disconnecting the coil connector and reinsert the connector. This help the connection. Add a little Silicone grease around the outside edge of the connector to prevent water/moisture from corroding the connector.

If you are getting idle wobble and stumble during acceleration with cold engine, ...you might try changing the Gas-Cap, Oil Filler Cap and O-Rings on dip-stick. When these items start leaking, they can trick the Evap. Can to release gas vapor into the intake and cause uneven A/F distribution. These items need to be changed every 3-4 yrs.

Last item, try changing the radiator cap 16-18 psi and top off or Drain/Fill with new antifreeze. When the radiator cap fail under low pressure 4 psi, it can cause a steam pocket in the heads causing misfire or knock and trick you to think you have enough antifreeze because it boils out into the overflow tank. Worst case it cause head warp and head gasket failure. In the old days, a 160F thermostat can increase 10 hp and remove this threat, but new cars do not like operating at low temp and trigger engine code. The Hyundai thermostat is not easy to change because of the location on my 2.4 l 4 cyl., therefore I perform a drain/fill (without flush) and new radiator cap every 3-4 years.

Hyundai TSB-Tech. Service Bulletin suggest using Chevron Techron with full tank of gas at every oil change. The gas filter is difficult to access because it on the gas pump in the gas tank. I like to use Chevron Techron once 2-3 months. I also like to put a tank of pure petroleum premium gas (no ethanol) once 2-3 months. The ethanol in the gas turn jelly in 2-3 months. ..it’s good practice to just carry around a bottle of Chevron Techron, to keep fuel pump, fuel regulator and injectors clean. And always use Top Tier Gas with detergent to prevent carbon build up and sooted injectors.

Best Wishes
 

·
Registered
Joined
·
51 Posts
The misfire did not completely go away for me after changing spark plugs (gapped and torqued) and the coil packs. I started worrying about a vacuum leak causing the issue next. Tested it by spraying carb cleaner around some of the vacuum lines. Inspected the PCV valve (shook it and heard rattling inside meaning it was good still). I guessed brake booster, but wasn't willing to attempt that, so got an OEM brake booster vacuum line with the check valve between and hooked it up quick, but didn't seem to resolve my degrading power and fuel consumption now too. Last week, on the commute home with 1500 ft elevation incline in about 10 miles, my Elantra GT 2.0 was struggling to maintain 65-70 mph. Downshifting to 4th or 5th helped a tiny bit, but the steepest part had me down to 60 mph, not great when others are passing at 75-80. Everytime I accelerated up through the gears the engine bay gave this whistling noise above 2500RPM and ONLY when accelerator was pressed. Let off of the gas, noise went away. Bad vacuum leak? Slipping belt? Loose pulley? Hyundai dealer says it needs a new engine, reporting they found debris in the oil. Same thing all the older Hyundai recalls were for...at 85K miles 2nd owner, I'm out of powertrain warranty, but dealer created case with Hyundai to see if anything can be done to help with the dealers quote of $12K to replace engine with short block since long blocks are unavailable. I have been looking to get a Veloster N as my next car, but after this, won't be coming back to Hyundai...
Thanks for the story. Sorry to hear this.
 

·
Registered
Joined
·
176 Posts
I almost did a few months ago. I test drove a Veloster N and fell in love with it. I was too hesitant and ended up getting burned by this issue. Looking at Toyota Corolla Hatchbacks now...getting off topic lol Should go scope out the Toyota forums, eh? Lol
Lol yes you should.
 

·
Registered
2016 Elantra GT 2.0 AT & 2011 Sonata SE 2.4
Joined
·
16 Posts
Before changing the coil pack. Inspect your coil boots and spark-plug spring connector. If the boots are worn, brown track and moisture got in, the spark-plug spring connector can corrode. The two boots and spark-plug spring connector will fail before the spark-plug or coils.

Go to www.RockAuto.com and find the coil boots/spark-plug spring kit. The A/C Delco kits are $3 per plug. Get some high temp. Silicone Dielectric Grease for the boots.

Do not use regular grease on the boots. They will carbon up and cause shorts or misfire.

I know Hyundai do not recommend using anti-seize. I use a very light blush of Nickel anti-seize, to prevent corrosion and improve conductivity. Brush off any corrosion from spark-plug threads. Brush off any corrosion from the coil lock-down bolt and use a light blush of Nickel anti-seize on the coil hold down bolt to promote grounding.

Do not use Zinc or Copper anti-seize. Zinc and Copper will form a low temperature alloy and fuse the spark-plug to the Aluminum heads.

Try disconnecting the coil connector and reinsert the connector. This help the connection. Add a little Silicone grease around the outside edge of the connector to prevent water/moisture from corroding the connector.

If you are getting idle wobble and stumble during acceleration with cold engine, ...you might try changing the Gas-Cap, Oil Filler Cap and O-Rings on dip-stick. When these items start leaking, they can trick the Evap. Can to release gas vapor into the intake and cause uneven A/F distribution. These items need to be changed every 3-4 yrs.

Last item, try changing the radiator cap 16-18 psi and top off or Drain/Fill with new antifreeze. When the radiator cap fail under low pressure 4 psi, it can cause a steam pocket in the heads causing misfire or knock and trick you to think you have enough antifreeze because it boils out into the overflow tank. Worst case it cause head warp and head gasket failure. In the old days, a 160F thermostat can increase 10 hp and remove this threat, but new cars do not like operating at low temp and trigger engine code. The Hyundai thermostat is not easy to change because of the location on my 2.4 l 4 cyl., therefore I perform a drain/fill (without flush) and new radiator cap every 3-4 years.

Hyundai TSB-Tech. Service Bulletin suggest using Chevron Techron with full tank of gas at every oil change. The gas filter is difficult to access because it on the gas pump in the gas tank. I like to use Chevron Techron once 2-3 months. I also like to put a tank of pure petroleum premium gas (no ethanol) once 2-3 months. The ethanol in the gas turn jelly in 2-3 months. ..it’s good practice to just carry around a bottle of Chevron Techron, to keep fuel pump, fuel regulator and injectors clean. And always use Top Tier Gas with detergent to prevent carbon build up and sooted injectors.

Best Wishes
Thanks for the detailed feedback! I actually would run half a bottle of Techron through the fuel tank and pour the other half in the vacuum port with a small funnel to clean the intake valves before oil changes. Each use quickened throttle response and power in lower and upper RPM. I found pouring Techron in vacuum line better than spraying CRC Intake Valve cleaner through it. Techron had a higher concentration of PEA, carbon cleaning solvent.
 

·
Registered
Joined
·
852 Posts
Thanks for the detailed feedback! I actually would run half a bottle of Techron through the fuel tank and pour the other half in the vacuum port with a small funnel to clean the intake valves before oil changes. Each use quickened throttle response and power in lower and upper RPM. I found pouring Techron in vacuum line better than spraying CRC Intake Valve cleaner through it. Techron had a higher concentration of PEA, carbon cleaning solvent.
Yup! Walmart have the concentrated Chevron Techron 10 oz for 20 gal of fuel for $4.95. I usually buy the box of 6 on sale and it last 6 month for three cars. It’s very cheap insurance to keep everything clean.

Once the modern fuel injection system, fuel pump, fuel regulator injectors and fuel lines gets clogged or carboned, it’s nearly impossible to repair. You have to replace everything or trapped crud just keep clogging the systems.

$20 per year for Chevron Techron is much cheaper than a full injector and fuel system flush, ...and much cheaper than changing out all those fouled components in the fuel system.

Thank you for the Like.
Best Wishes.
 

·
Registered
2016 Elantra GT 2.0 AT & 2011 Sonata SE 2.4
Joined
·
16 Posts
Update: Hyundai Motor America approved 100% of engine replacement in my Elantra GT w/ rental coverage. I am pleasantly surprised both at the news and at how quickly the resolution was reached. Now we'll see how long the process will last.
 

·
Registered
Joined
·
176 Posts
Update: Hyundai Motor America approved 100% of engine replacement in my Elantra GT w/ rental coverage. I am pleasantly surprised both at the news and at how quickly the resolution was reached. Now we'll see how long the process will last.
Wow that's unexpected. Congrats on that.
 

·
Registered
2016 Elantra GT 2.0 AT & 2011 Sonata SE 2.4
Joined
·
16 Posts
I didn't get details on why it was approved from either the dealer or HMA, but picked up the rental today: 2020 Accent 1.6L w/ 8SPD auto trans. Gas mileage is crazy good on this thing...averaged 40+mpg
 
21 - 30 of 30 Posts
Top