Possible engine failure or bad gas?
I have been looking at this 2011 Forte to see why it is running rough, and I suspect it's possibly a bad engine but just looking for a second opinion. Engine has 154k miles.
The first thing done was changing the spark plugs as a gamble. No fix, of course. Cylinders 3 and 4 also had a lot of oil on the spark plugs... More on that in the compression test numbers.
The first thing I checked for was codes about the problem. Regrettably, I forgot the code, but I saw a generic Cylinder 1 misfire code. To rule that out, I swapped coils, cleared the codes, and re-scanned. It's the same code on the same cylinder. I'm not too surprised being it uses Denso ignition coils.
The next thing I checked was the compression. This is where I begin to be leary of the engine. The other thing I noticed (but can't show, my borescope camera doesn't support image saves but cylinders 1, 3, and 4 have oil from bad rings; 3 and 4 being the worst, and also have the worst compression numbers.
- Cylinder 1 (left): 1,350KPa
- Cylinder 2: 1,325
- So far so good. Kia/Hyundai says there should be a 100KPa differential on this engine at most. A little deviation will happen with this many miles on anything, so nothing concerning.
- Cylinder 3: 1,250-1,350KPa
- 100KPa differential, ick. It wouldn't be worrisome if isolated and it's fine, just a death sentence with Hyundai/Kia when it's worse.
- Cylinder 4: 1,100-1,300KPa, 1,200KPa on the 2nd test
- 100-200KPa differential. Not great.
Cylinder 4 is all over the place. Cylinder 3 is borderline at best.
The only thing I have not checked is the ethanol and fuel injectors, yet. That's next.
In the meantime, I'm weary of the engine and based on those numbers and I do suspect the engine is potentially NFG given the inconsistencies with Cylinder 4 and Cylinder 3 being borderline. I've even tested Cylinder 4 4 times, the others were baseline run and checked a 2nd time. The only test I didn't check is the wet compression. I saw everything I had to see.
Update (03/08/24)
Update on the checks: Checked the gas, 10% ethanol. It's gotta go back under the microscope.
Update (03/12/24)
Swapped injector 1 to 2. Code moved.
Update (03/20/24)
And I'm back with yet another report. Sigh...
So I swapped the injector, and it had the same codes.
I swapped the replacement injector into Cylinder 3 (and put the good one in Cylinder 2), same codes
The only things I can see to try are the connector and if that doesn't work it looks like a PCM/ECU or engine failure.
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2 件のコメント
Bingo, we have a winner!
Jerry Wheeler さんによる
@dadibrokeit It used to say Generic, not Kia. I guess clearing it 2+ times knocked it out of Generic.
Guess I was just a bit put off by 154k being the near end when I'm used to Toyotas routinely hitting near 200k miles before things break down and being fine when I saw the initial compression numbers. And it's usually not the engine outside of the 2AZ-FE; always something like the alternator.
Nick さんによる