2.0T running rich

[Mrtheplague]

I have a feeling that the engine is running a little to rich and that is the reason for the black soot on the exhaust. This one of the issues that turbo engines have they don't run at a perfect air fuel mix. I am wondering if Hyundai might come out with a new update on the timing to lean things out so help the fuel economy. any thoughts?

[SantyNC]

Although this is my first turbo, I've always been taught that black soot means the engine is running too rich. But when you search Google you get back about even results that a turbo always runs way versus something ain't right. So I wonder why I don't see black soot on VW Tiguans or Subaru Foresters. I don't even remember seeing any on the other Hyundai Turbos like the Sonata or Kia Optima. Makes you wonder.

[donnie71281]

My Optima Ex-turbo was the same way. It is normal and nothing to worry about. These turbos run rich at start-up to help the cat heat up quicker and achieve the emissions rating.


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[dtech]

turbos will by design run a richer mixture under heavier boost conditions - this prevents pre-ignition and protects the engine. Equipment at the dealer can be hooked into the cars electronics to determine whether the fuel/air mix is correct under various conditions.

but just because you are seeing some black soot on the tailpipe doesn't necessarily mean the fuel/air mix is out of spec. There is a learning curve with auto makers and using turbo charging - let's hope Hyundai is far along the curve.

[igotzzoom]

I've just gotten used to wiping my tailpipe tips down every few days. Turbos typically run rich as a safety precaution at WOT to prevent detonation. Also, rather than a conventional EGR system, Hyundai basically performs the same function through exhaust cam phasing, which keeps the exhaust valves open for a little on the downstroke, sucking back in a little exhaust.

My father-in-law-who is a mechanic says he sees a lot of cars come in with very sooty EGR systems that need cleaning out. I'm thinking our sooty tailpipes is just what would otherwise be going into the EGR system.

Besides, I've heard some real horror stories about early VW and Audi direct-injection engines that got major carbon buildup on the intake valves, so if slightly sooty tailpipes is the tradeoff, that's fine with me.

[Mrtheplague]

do you think the fuel economy would be better if they leaned it out a bit?

[igotzzoom]

Would you rather have a little better FE or a detonated engine? The 2.0T is capable of very good fuel economy if driven prudently. If FE was a bigger concern than power, maybe you should have gotten the base 2.4.

I feel the small sacrifice in economy with the turbo was well worth the 76 hp gain. Note that the 2.0T was not one of the engines called out in the fuel economy mea culpa from Hyundai/Kia.

[grandpaswagon]

Originally Posted by igotzzoom

Note that the 2.0T was not one of the engines called out in the fuel economy mea culpa from Hyundai/Kia.

It certainly was on the Santa Fe.

[igotzzoom]

Originally Posted by grandpaswagon

It certainly was on the Santa Fe.

I stand corrected. It wasn't for my model. Having driven the new Santa Fe, I think it's a great model otherwise.

[SantyNC]

Oh yes, if my choices are the 2.4, dirty engine (EGR) or soot on the tailpipes? Dirty tailpipes it is!

I run around pretty timid most of the time, but when I need to scoot into that opening or pass the slow-poke, I've got it.

Yes Sir, the Santa Fe with Turbo is a great choice, even if I have to wash the pipes 2 times a week.