What ever you do, don't get the one that looks like a coin with the numbers around the radius.....They are notoriously inaccurate. I purchased a "Tune-Up" package from Advanced Auto for 6.99....It has the wire gauges which are much safer than trying to sandwich a bunch of metal plates between the gap in the spark plug. Just gently try to pass the wire gauge through, don't force it... The specific one I bought had .030 and .034...So I made sure the .030 passed through freely and that the .034 would not. Close enough for me....And certainly better than what they were gapped at.

 

I got my wire gauge from NAPA...$2.99

 

Then we can agree that mine is clearly better than yours...LOL....JK!!!!....Anyway Spool, it's probably better to go into the store whether that be Napa, Avanced, Autozone, and look at them. some are different than others and have different increments....At Advanced they had 4 different kinds but only 1 of them had the gauges in the range of .030 through .035

 

Mine has six measuring wires!
:harhar:

 

Thanks for the advice. I have an Advanced and a Napa right down the street so I'll go check them out.

 

I bought one at sears that was Similar to a Swiss army knife with both wire hooks and plates and it had .032 on it. My factory settings were all .028 and I gapped them to .032. Didn't notice a difference as far as driving but the mpg improved a bit.

 

Dear Henry Hall:

Thank you for contacting Hyundai Motor America. We appreciate the opportunity to clarify the spark plug gap for the 2011 and 2012 Hyundai Sonata Turbo.

We have confirmed that the gap for the spark plug in the 2011 and 2012 Sonata Turbo is 1.0 to 1.1. This information is available in the Shop Manual for these vehicles. For any additional questions regarding the spark plugs in your Sonata Turbo we recommend contacting your local Hyundai dealership. The factory trained technicians at your Hyundai dealership are the most qualified to address your question and provide you with expert advice.

To locate one of our authorized Hyundai dealerships in your area, you can either visit our website http://www.HyundaiUSA.com (click on “Find a Dealer” in the upper right corner, enter your zip code and click on “Locate”) or call our automated dealership locator at 866-400-0384.

We have documented your inquiry in our system under Case # 4678588. Your Case # can be referenced if we can provide further assistance.

Thank you for contacting Hyundai Motor America.

​

Email From Customer (Henry Hall)

01/03/2012 05:55 PM​

Hi.
There seems to be a lot of debate over what the actual spark plug gap should be for the TURBO. Even my Hyundai tech is not sure and my contact at Denso states that it should be -08mm / .32 . Yet, the HMA site only mentions 1.0 to 1.1 as the gap, even though the plug is rated for less. These engines need to have the proper gap of the plugs to run the way Hyundai meant for them to run. Can you provide a clear cut explanation and the proper GAP? Many folks would be greatly pleased. Thank you,
Henry

Henry A Hall II
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Sorry for not having more input lately, but after getting my new plugs at 30k and realizing they were all gapped at .30, I was confused and frustrated. Having an improper gap can AND will cause problems eventually. The gap of .30 is way off the 1.1mm , and for that matter, so is the Denso recommendation of .32. 1.1 seems to be on the verge of leaning the engine out.....can that happen with these engines? My Tech seems to think so and he is a graduate of GA Tech, so he should know a little more than us, right? Haha

 

This spark plug gap issue is ambiguous.

Hyundai recommends 1-1.1mm for the gaps, and no information is publicly available from Hyundai that states otherwise for the 2.0T engine.

Unless I misread his post, SBR711 (who is the Hyundai tech, right?) says 1-1.1mm is the correct.

The source of the .8mm gap specification is http://www.denso.co.jp/ja/products/aftermarket/repair_parts/plug/cross_ref/pdf/partnumber.pdf

SBR, would you please clear this up? Is the proper gap .8mm or 1-1.1mm for the Turbo?

Hal

 

I'm fairly certain everyone is saying that the 1-1.1mm is absolutely incorrect. The picture posted earlier in this thread is not for the 2.0T but rather the 2.4. .8mm is the correct gap.

 

OK....Let's all stop and take a deep breath......I know the Sonata Turbo has been a rather frustrating car to own....Between the left pull, hesitation, problems with the turbo, etc, etc....However...I think we need o think of this logically. If Hyundai specifies 1.0~1.1, then why oh why were my plugs gapped between .021~.028....I know that doesnt convert correctly....Any how, after regapping my plugs to .032, there has been a vast improvement in engine feel....I know I have read on another forum, and possibly here that Hyundai duplicated the information for the 2.4 and put that down for the 2.0 turbo.....Basically this is my thought process......I am sticking with the .032 gap, if anything breaks I will play dumb and say I have no clue what happened. Plus I have never owned a car long enough to not have a warranty...

 

Sorry if my post makes it seem like I'm worked up. I'm not. I'm as cool as a cucumber on this issue. My Turbo runs great, and I have no reason to even check my plugs.

It appears as though Hyundai is going with 1-1.1mm gaps even for the Turbo. The manual recommends changing spark plugs at 30k miles for severe service, and the Turbo was released in 2010. As owner near the 30K sever service schedule, dealerships will be changing spark plugs on Turbos. If 1-1.1mm is no good, Hyundai service departments experience lots of angry customers bringing their car back after getting the plugs gapped incorrectly!

So I guess my question for clarification still lingers: How do we know Denso has it right and Hyundai has it wrong (or vice versa?)

SBR, where are you buddy!?

Hal

 

It seems to me that the folks who designed, built, tested and warranty the engine would know best.

 

you have too much faith lol

 

Sometimes a manufacturer knows there was a mistake but does a silent recal. As vehicles come in for maintenance or service they make the adjustments. The following year the owners manual will have updated information.

 

Sometimes a manufacturer knows there was a mistake but does a silent recal. As vehicles come in for maintenance or service they make the adjustments. The following year the owners manual will have updated information.

I completely agree with you...Not to flame Hyundai, but it would appear as tho they really didn't have their stuff together when they released the Turbo model. Wastegate rattle???? Which by the way, when i brought my car in for that problem, they service department stated it was a faulty heat shield and replaced that..LOL.... Severe Pulling??? so it is possible for them to make something and have it turn out not to be what they intended..I'm sure they would have found that the original Turbo pulled to the left during their testing. What i would like to hear is someone chme in who has checked their plugs and found them to be 1.1, which I think equates to .045...

 

I have an appointment on Thursday to have something checked out and I want to have them check my spark plug gap and re-gap them if necessary, how do I go about having them do this? If I just ask will they oblige and cover it under warranty or is there a trick I need to know in order to get this covered under warranty?

 

Ask them outright.

 

I asked the dealer today that my car is at for the blown motor if they could check it since I won't be driving it anytime soon. I'll see if they get back to me on it.

 

Just so you guys know...they may not set it to what you ask them to. They WILL refer to the manual for proper gapping, which we are still unsure about being correct, so they might set it to .040...which may be too lean...and the engine may stutter/detonate under certain circumstances. When you ask them, mention the manual specs being the same for the 2.4L and the 2.0T engines, see what they come up with...maybe they got information from corporate for the right specs? Also, if you could, grab a manual from one of the 2012 and see what it says about the gapping for the newer models.

 

All,
BTW I want to thank everyone for your input on this subject but now I'm going to drive deep:
The ignition coils part numbers are not the same for the two cars, but the question is what is different between them.
So I’m off to find the specification sheets for these two parts.
2.4L is Part# 27300-3F100
and
2.0T is Part#2730-2G700
Spark Plugs are CUSTOM not standard to USA or EU, so if this is a custom part would you not follow the Mfg specification sheets???
DENSO SPARK PLUGS
or
http://www.globaldenso.com/en/products/aftermarket/plug/catalog/europe/pdf/pdfcatalog_eu_gbr.pdf
vs.
Denso JP:
http://www.denso.co.jp/ja/products/aftermarket/repair_parts/plug/cross_ref/pdf/partnumber.pdf

FXU16HR11 Iridium 0.55 Ir Pt NEEDLE R S (Gap 1.1mm) Double Needle and no cut-back GND electrode
vs.
ZXU20HCR8 Iridium 0.55 Ir Pt R S 0.8 (Gap 0.8mm) Cut-back GND electrode (One step cooler from 16 to 20)
LAST I did experiment with a 1.1mm and for MY car it caused it to stumble at boost pressures past 15.5 psi, dropped to 0.8mm and no more stumble to the a max of 17.4 psi.
Cheers,
Phil

 

my car is getting 16-18mpg since i first got it in september. These days i'm doing a 60 miles drive both way to my job and i can't get it higher than 21mpg. It's **** cold tho over here but the sparks are defenitively something i need to check!!!

 

I had 702 miles on my 2012SE this morning. In that 702 miles I've experienced quite a bit of rough idling at 750rpm and lower. Hesitation in the throttle and massive amounts of exhaust. Literally clouds of exhaust at all times while the car was running. I finally got a chance to check my plugs this morning. The first two were at .28, the third was under .20 almost touching the tip and the fourth was .28. I'm guessing that third plug was smashed in a bit when being installed and the major cause of the rough idling. I gaped them all to .32 and the rough idling is almost gone. I can still feel a little rumbling but the tach doesn't flicker like it was before. The billowing smoke from the exhaust is gone. Cruising seems to be more smooth. Throttle response has definitely improved. I don't feel any overall performance gain but there could be, I just don't feel it.

 

Anybody have suggestions on how I can check the gaps myself?

 

Get a gap tool. I got one at sears with both wires and slides on it. The plugs are underneath that plastic cover on the engine. Just lift it straight up to take it off. You'll need a few sockets but I don't remember what size. I think there was a step by step in either this thread Or another. Failing that I believe there are a few videos on YouTube you can check out.

 

My gap is set at .32, regular gas, Valvoline Syntec 5w-40, mostly highway driving at 70-80mph, and I'm averaging 26mpg via real calculation.

 

Definitely need to be using, 20 weight . . . as I was chided "your turbo WORKS on oil pressure, viscosity needs to be right" . . . isn't that in the manual for turbo's too ?

 

10mm to take the boot off, and a standard spark plug socket plus an extension to get the plugs out.

 

I'm bringing the car to the dealership next week for few things like creacking sunroof (since a week or so) and central armpad being loose. I ask them on the phone if they could check the spark plug gap and they told me they would if i show them a official tsp.

I found something that could have been good on page 7 of this thread, but it's for the n/a (1.1 gap)

is there something official i could print for them

car mileage ain't good at all on the highway, i'm pretty sure this got something to do with that

 

How about showing them the specs in the owner's manual (or where ever the gap specs are)...and let them see what yours are at.

 

the only thing i saw so far was this:

but that's for the regular sonata. Anyone had their spark plugs reggaped at the dealer on warranty?

 

Checked all mine...
.24 .27 .26 .26

 

This should be the last post regarding the issue of what we should be gapping our plugs on the Turbo. All those folks with 2.4's, please do not comment as this is a TURBO thread. The engines were tested with a gap of .....................08mm!!!!! do not gap at 1.1mm or you will eventually damage the engine as it WILL LEAN OUT. My info came from 2 sources....a Hyundai rep in AL at the plant and from his counterpart in Korea. If anyone feels they need to continue to doubt this info - I do have better things to do but this is important, then learn Korean and call up Hyundai at their testing facility. I really appreciate all the feedback from everyone and look forward to some new topics.

 

Depeche93, I think we can all appreciate a good, productive discussion about an important topic, but this "I know a guy at Hyundai" stuff is impossible to take seriously.

Here are the facts: Denso says the gaps should be .8mm. The only publicly available information from Hyundai says 1.1mm.

Yes, some are claiming that 1.1mm is for the 2.4 NA engine. That may or may not be correct. However this is a fact: www.hmaservice.com publishes the photo posted by Xprime on 2/6/12. That photo/spec is listed for BOTH the Turbo and the NA engines.

This has been a great thread, but we still have failed to credibly or definitively answer this question: Which gap is correct?

Hal

 

Finally had a nice enough day since purchasing my car.... All plugs were originally gapped at .028", and I have regapped them to 0.032". I really haven't noticed any difference, but then again, driving only 10 miles won't be much of a test. Will comment back in a few days....