engine sputtering

[perrymk]

I suppose this could be a million and one things, plus I'm no mechanic, but I'd like to get some ideas before bringing it to the dealer.

The car
2014 Sonic hatchback, owned since new, 1.4T, 6 speed manual, 89000 miles. Almost always use non-ethanol gas from the same station. In fact the previous several tanks were non-ethanol from the same station.

The situation
I was driving home from a day trip on the interstate using cruise control. It was a warm day, probably upper 90s and reportedly hit 100 in a few places I passed through. I noticed the problem when going up hill. Not an extreme hill, this is an interstate in Florida, but probably required some extra RPM. I haven't done any particular hauling or dusty roads recently. I had my normal load this trip, nothing heavy.

The problem
Engine occasionally sputters. The nearest I can relate is that it felt like water in the fuel. I say this as this turned out to be the problem in a previous vehicle with similar symptoms. I re-fueled along the interstate (89 octane up to 10% ethanol; couldn't find the non-ethanol pump). Problem persisted. Occasionally it sputters so much it disengages the cruise control. I've noticed this at 45mph and 75mph. It usually only lasts a second or two, maybe up to 3 or 4 seconds. But still a hesitation. It doesn't happen on every hill or every increase in RPM.

Other stuff
The check engine light has not come on. It otherwise runs fine. I've not had any problems with this car previous. I monitor the gas mileage and the previous tanks are all as expected, usually around 38-39mpg depending on amount of highway vs city driving. I follow the owner manual schedule for maintenance and do simple stuff myself. Oil changes, spark plugs, etc. I check oil level and tire PSI regularly.

My thoughts
-Wait another tank or two of fuel before taking it in. Maybe it is the fuel.
-It is due for an air filter soon so get that in now, but it just doesn't strike me that this would be the problem all of a sudden. It was on a lawn mower once though.
-Buy a Scangauge or similar to monitor while driving. I'm open to suggestions as exactly what to get and what this will tell me. I already have a code reader but as the check engine light has not appeared I haven't used the code reader.


I'd appreciate any comments. Thank you.

 

[christian4917]

https://r.tapatalk.com/shareLink?ur...&share_tid=23449&share_fid=38994&share_type=t

A bunch of us have had similar problems to this. Maybe its the same issue? Who knows. I think the general consensus of that thread is ignition issues.

Sent from my SM-N960U using Tapatalk

 

[DuluthSonic]

Had the same kind of thing happen last summer. Going up hills I would get a sputtering with no check engine light. Seeing that I am the second owner and not knowing if the plugs had ever been changed, I started with that. When I pulled the coil pack off I noticed that one of the springs was stuck a little ways up in the boot. Don't know if it was that or the new plugs, but I've never had the issue again.

 

[skurtov]

Plugs and wastegate. Drop a stage colder, NGKBKR7E is a good copper plug.

 

[gnonne]

Definitely plugs or a coil pack.

I had a Saturn that did this very same thing about 20 years ago with very low miles. The dealer fooled with it for a while, and finally found that there was corrosion between the ignition module and the engine block causing it to produce a weak spark, which was only noticeable when going up hills after the engine had warmed up. This was caused by the car sitting outside with no hood for a few weeks while they waited for parts - it was backed into by the transit truck before I bought it... As I recall, they took it apart, cleaned it up, and reassembled it. I never had the problem again.

Of course the newer vehicles have individual coil packs for each plug, so the solution will not be exactly the same, but it is the same problem - weak spark.

https://www.amazon.com/ACDelco-D521...automotive&vehicleId=1&vehicleType=automotive

 

[perrymk]

Thanks for all the ideas. From the other thread and this one it seems the coil is a likely culprit, followed by spark plugs. I will certainly try the NGKBKR7E. I seem to recall while trying to do a tuneup a while back I broke a couple of the spark plug boots so bought new coil to get the spark plug boots. I have since learned that NAPA sells the spark plug boots individually but now that means I have a coil sitting in the garage to try. I actually don't know what a wastegate is (did I mention I'm not a mechanic?) but I have the manual and will look it up in case the coil and spark plugs don't resolve the issue.

 

[christian4917]

I have tried replacing the pack because my boot tore as well but it did not fix the issue going back with an OEM pack. Tails has the MSD pack(aftermarket that claims to be better) and said he would update soon if it helps any.

Sent from my SM-N960U using Tapatalk

 

[skurtov]

Thanks for all the ideas. From the other thread and this one it seems the coil is a likely culprit, followed by spark plugs. I will certainly try the NGKBKR7E. I seem to recall while trying to do a tuneup a while back I broke a couple of the spark plug boots so bought new coil to get the spark plug boots. I have since learned that NAPA sells the spark plug boots individually but now that means I have a coil sitting in the garage to try. I actually don't know what a wastegate is (did I mention I'm not a mechanic?) but I have the manual and will look it up in case the coil and spark plugs don't resolve the issue.

I would recommend buying the MSD upgraded ones for the coil packs

 

[perrymk]

UPDATE

So this morning I went for my usual hike at a local wildlife management area. Plenty of sputtering on the way there. I thought it might be getting worse. I got home and did some chores to give the engine time to cool.

Recall I mentioned breaking a spark plug boot and buying a whole coil pack to get a couple of spark plug boots? This was at 60K miles, as that's when the Owner Manual says to change the spark plugs. I'm at 89K miles now so 29K miles with the Autozone coil piece. I think it was from Autozone but there is no name on the part. It was a local place, not internet mail order. Anyway, I still had the original coil piece with 60K miles on a shelf in the garage. I also had 4 new spark plug boots (I guess that's what they're called) that consist of a rubber outer and a spring inside that I purchased from NAPA auto parts. So I pulled off the remaining spark plug boots and put 4 all new spark plug boots on the original coil piece with 60K miles. I removed the 29K mile Autozone coil, put on the 60K mile original coil with the new spark plug boots.

I then ran some errands in town (I live about 15 miles from town). I drove part of the same way I went hiking and got past where it sputtered earlier this morning. I got on the interstate, used the cruise control and went up a substantial (for here) hill at 75mph. I used cruise control on some 45 and 55 mph roads. I drove around town, running my various errands. I came home.

No sputter.

I was all set to drive a couple tanks of gas to be sure it wasn't water in the gas and take it to the dealer and likely pay a few hundred dollars. But as I had the parts in my garage I didn't have to spend any money today, at least not on the car.

I'm feeling pretty good about myself right now. I'll be watching how that aftermarket coil works out in case this 60K mile original coil gives up the ghost. I may even order it to have at the ready if the review sounds positive.

Thank you all for the advice!

 

[perrymk]

I was searching for a coil to have in case my current one gives up and saw NGK makes one. As they have a good reputation for spark plugs I thought they might make a good coil piece also.

 

[gnonne]

Interesting to hear that 60K is the recommended interval for the plugs/pack. I think most people get more miles out of them than that. I've had three Sonics and never replaced one yet. Maximum mileage is 90K on the three, all original plugs/packs.

There is probably a reason the no-name coil packs on eBay are $37 and the AC Delco is $77... I doubt the local parts stores have higher quality than eBay. I buy all parts on rockauto.com, when you can pick the brand and price.

 

[perrymk]

Interesting to hear that 60K is the recommended interval for the plugs/pack. /QUOTE]

Just the spark plugs are recommended for change at 60K miles. I replaced the coil because I broke a couple of the spark plug boots taking out the original coil to get to the plugs and had to buy a new coil just to get the spark plug boots. I now keep spare spark plug boots in my garage as those must be special ordered; they don't stock them locally.

 

[perrymk]

Yet another follow up.

I ordered NGK spark plugs and the NGK coil pack. After doing some more reading online I opted to go with iridium spark plugs as they are reported more durable than copper. I'm more about durable and gas mileage than I am about power. Although they were significantly more expensive at around $7.50 per plug. I don't buy them that often so decided to try them. I noticed my old plugs showed significant wear even though they still worked fine.

I also received the NGK coil pack. I opted for NGK over MSD as NGK has more consistent good reviews where the MSD had the occasional negative experience. I ordered from Rock Auto as they had the best price at about $112 vs $130-$150 at most places.
The only apparent difference between the NGK coil pack and the OEM Delphi coil pack is the Delphi coil pack has a Delphi name at one end, whereas the NGK coil pack has the NGK name at one end and the Delphi name at the other end. It appears very much like the NGK is simply a Delphi with an additional name stamped on, and about a $40 increase in price. Lesson learned.

I installed the NGK spark plugs (I realize they weren't due for another 30K), the NGK coil pack, and the new air filter. Everything runs fine. I may offer another update in a few weeks to report if the gas mileage is affected. I've recorded every tank since new as I believe MPG is a good way to monitor for problems. Plus I'm a little obsessive.

Thanks again for the advice.

 

[gnonne]

As long as you are just a little obsessive its OK.