Newbie question -- 3.8 Engine Sound on Moderate Acceleration

[JimInNashville]

Hello everyone,

I just took delivery of a new Genesis 3.8 Sedan after my 2003 Honda Accord 6 was totalled by a teenager who was "distracted". I was stopped on a straightaway behind a woman turning left, and he hit me at 35 MPH.

Overall, so far, I think the Genesis 3.8 is amazing. My Accord 6 was refined and powerful, but the Genesis accelerates effortlessly in situations where the 240hp Accord really had to wind out. The Genesis is more stable, and, amazingly, has actually gotten slightly BETTER mileage than the Accord! (23 mpg in a mix of city and highway driving, with about 2/3 highway).

One thing puzzles me slightly, and I wonder if you can help. On moderate acceleration, the Genesis 3.8 engine makes a "burbling" sound that is very noticeable, and sounds almost rough when starting out on a quiet, smooth road. It is almost reminiscent of some small block V8s I drove as a kid in the 60's.

Is this normal? The noice is considerably more noticeable than the turbine-like sound of the Accord 6. Sort of like a wah-wah-wah-wah rumble.
Do you folks hear the same thing?

Thanks,

Jim

 

[Ron Veenker]

I think that is what I hear and have wondered about as well. I have been thinking that it is the six-speed transmission shifting rather quickly if you accelerating from a dead stop and not pushing the rpm.

Although I live in southeastern NC, I bought my 2009 3.8 at Hallmark Hyundai in Hendersonville, TN. Did you get your's from Jim Reed? Just curious.

Ron

 

[JimInNashville]

I think that is what I hear and have wondered about as well. I have been thinking that it is the six-speed transmission shifting rather quickly if you accelerating from a dead stop and not pushing the rpm.

Although I live in southeastern NC, I bought my 2009 3.8 at Hallmark Hyundai in Hendersonville, TN. Did you get your's from Jim Reed? Just curious.

Ron

Ron,

Thanks for your reply.

No, I drove out to Wilson County Hyundai, as I'm quite tall and didn't want the moon roof, and needed the base model.

I believe the noise I'm referring to is definitely an engine noise, as it is an engine rhythm. Almost sounds like an exhaust vibration, you know, "wah-wah-wah-wah-wah" in rhythm with the engine revs.

 

[Ron Veenker]

Okay, Jim, that's definitely a different issue. I'll be watching for comments here to learn something myself.

By the way, I wanted a black/black 3.8 and all Hallmark had was two of the metallic blue cars. As I was about to leave, a salesman from Wilson County Motors of Lebanon, TN pulled up to talk to someone. I bought the car.

Ron

PS: BTW, I have two sons who live in Hendersonville; I was visiting for Christmas.

 

[jwaters943]

My prior DD was a 2006 Honda Pilot. By comparison, I find the V6 in my Genesis to be even smoother and more quiet at idle and when accelerating. Under moderate to heavy acceleration the Gen's Lambda V6 does emit a sound that is deeper than the Honda's J-Series engine....I could see how some might liken it to the sound of a V8-like, but not quite as deep and pronounced. I quite enjoy the sound and don't think it's abnormal. In most situations under light to moderate acceleration you can barely tell the engine is on.

 

[Hghwy52]

I've noticed an unusual noise going through the first few gears under light to moderate acceleration as well. Mine sounds something like a rough grinding noise - not really unpleasant but not like a nice exhaust burble either. At first, I thought it might be the transmission but it sounds more like it's coming from the engine. Other than that, the engine is smooth, very responsive and generally quiet. A while ago, someone posted that they had a sound like a playing card stuck in a bicycle spoke when accelerating which could be describing the same thing. Whatever it is, it is less noticeable now after 15 mos. and 18K miles.

 

[ilovemygenesis]

I;m wondering if the sound is coming from the muffler?

 

[JimInNashville]

I;m wondering if the sound is coming from the muffler?

It could be. It could be some kind of resonance. It's not really unpleasant, but it sounds slightly on the raspy-rattly side, not really smooth and "luxurious" at all.

Perhaps it is a deliberate attempt by Hyundai to add "sportiness" to the equation, I don't know. I guess I'll eventually take a ride over to a nearby Hyundai dealer and ask the service manager to listen.

Certainly the engine is performing well, but I've learned through my many years of driving that a careful listen can save you so much grief!

 

[JimInNashville]

My prior DD was a 2006 Honda Pilot. By comparison, I find the V6 in my Genesis to be even smoother and more quiet at idle and when accelerating. Under moderate to heavy acceleration the Gen's Lambda V6 does emit a sound that is deeper than the Honda's J-Series engine....I could see how some might liken it to the sound of a V8-like, but not quite as deep and pronounced. I quite enjoy the sound and don't think it's abnormal. In most situations under light to moderate acceleration you can barely tell the engine is on.

Thanks for your respone. Yes, what I'm hearing is not necessarily pathological, but slightly more "edgy" than I would have thought you'd hear from a car competing with Lexus. Certainly not a Lexus-like noise.

 

[jwaters943]

Well, they did also benchmark the Infiniti M. In terms of engine noise/sound maybe they tuned it to be a bit closer to Infiniti?

Have you driven another Genesis to see if this is an issue with just your car?

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[JimInNashville]

Well, they did also benchmark the Infiniti M. In terms of engine noise/sound maybe they tuned it to be a bit closer to Infiniti?

Have you driven another Genesis to see if this is an issue with just your car?

Thanks, of course that would be the clincher.

 

[JimInNashville]

I drove over to Wilson County Hyundai in Lebanon, TN, arriving around 8am. The sales (Jeff Mazza) and service staff there greeted me like a returning dignitary. Honestly. The top mechanic and the service manager both went for extended drives in my car, then we took another Genesis 3.8 out for a spin. The one from the lot made the same sound as my car -- perhaps *slightly* less intense, but basically the same sound.

Both the service manager and the top mechanic agreed the sound was noteworthy, and the service manager planned a followup with Hyundai to get a precise technical explanation. The sound can be described as follows:

a. I is most noticeable on light to moderate acceleration from a standing stop. It peaks just before the shifts.

b. What starts as an "mum-mum-mum-mum-mum" exhaust sound reminiscent of small block V8s from the 60's gives way to a "rock-rock-rock-rock" sound that sounds like an engine just on the verge of knocking.

c. Anyone who knows anything about cars can't miss the sound, once you listen for it.
Everyone who's sat in my car can tell you exactly when it occurs. It was described as sounding sort of like a bike sounded like when you put the playing cards in the spokes as a kid (if any of you ever did that).

d. It is not a particularly "good" sound. It sounds harsh, slightly tinny, and decidedly unluxurious.

e. The service manager's theory is that because the engine is spinning up under light load, the computer driven spark advance and valve timing push the engine to the verge of predetonation, which, of course, helps deliver the remarkable mileage you obtain. (In my 14 mile trip to work, with about 2/3 highway 1/3 city, I am averaging 23.3 mpg, as compared with 22.5 from my Accord 6 (with tires inflated at 36) under identical conditions. For a car of this size to deliver the performance I'm getting along with the mileage is pretty sensational.

HOWEVER, in my experience, non-musical sounds from a passenger vechicle are always a cause for concern, and I intend to pursue this.

Any 3.8 owners out there, please help on this account. On a quiet street, push a mild throttle acceleration and listen carefully as the engine peaks just before shifting. Do you hear it?

Also, let me add a plug for the guys at Wilson County Hyundai. Their willingness to spend a significant amount of time on this (after which they drove my car into the bay and topped off all fluids, free of charge, and gave me a complimentary bottle of water to take on my trip), and their attitude, were very refreshing, and I recommend them.

 

[Mchart]

I don't have said issue on my 3.8l Gen Coupe. What I do get though is what I beleive the same sound you are describing when the engine is cold. If I put any amount of load on the engine when it's cold, it will start making a much louder and deeper sound then it ever makes. After the engine warms up - Said sound is never made again. I have no idea if it's due to maybe like a pinhole exhaust leak that seals up when warm, or something else.

 

[JimInNashville]

I don't have said issue on my 3.8l Genesis Coupe. What I do get though is what I beleive the same sound you are describing when the engine is cold. If I put any amount of load on the engine when it's cold, it will start making a much louder and deeper sound then it ever makes. After the engine warms up - Said sound is never made again. I have no idea if it's due to maybe like a pinhole exhaust leak that seals up when warm, or something else.

Interesting, thanks. These engines and exhaust systems have some significant differences. I am thinking of trying to contact someone relatively high up in Hyundai and ask them. I may try making a digital recording and, if I capture the sound, emailing it to them.

--Jim

 

[Mchart]

Interesting, thanks. These engines and exhaust systems have some significant differences. I am thinking of trying to contact someone relatively high up in Hyundai and ask them. I may try making a digital recording and, if I capture the sound, emailing it to them.

--Jim

The intake manifold and surge tank are vastly different, and the exhaust is more aggressive. However, they are still basically the same engine, with the coupe 3.8l having a bit more airflow and a more aggressive tune.

 

[Solano]

I have a 3.8 and I may relate to the engine sound you are hearing during acceleration. I hear it too, but concluded the "noise" is normal. I've overhauled many engines and did my research on the 3.8 TAU engine before buying my Genesis.

Genesis 3.8 has solid lifters and valve timing chains, variable intake and exhaust timing. During acceleration, the ECU, thru solenoid valves and oil pressure, commands both camshafts (exhaust and Intake) to retard or advance to achieve peak engine performance and fuel efficiency.

To me, it sounded like it is retarding the spark timing to prevent detonation along with the automatic camshaft adjustments of both intake and exhaust valves. Don't miss the fact that Genesis 3.8 may have the biggest intake throat (almost 3 inches across) that I have seen for this size engine, contributing to the "throaty sound" we are hearing.

I'm very happy and satisfied with my Genesis and continues to love it each time I drive and watched people trying to figure out what kind of car it is, both on the highways and parking lots.

 

[JimInNashville]

I have a 3.8 and I may relate to the engine sound you are hearing during acceleration. I hear it too, but concluded the "noise" is normal. I've overhauled many engines and did my research on the 3.8 TAU engine before buying my Genesis.

Genesis 3.8 has solid lifters and valve timing chains, variable intake and exhaust timing. During acceleration, the ECU, thru solenoid valves and oil pressure, commands both camshafts (exhaust and Intake) to retard or advance to achieve peak engine performance and fuel efficiency.

To me, it sounded like it is retarding the spark timing to prevent detonation along with the automatic camshaft adjustments of both intake and exhaust valves. Don't miss the fact that Genesis 3.8 may have the biggest intake throat (almost 3 inches across) that I have seen for this size engine, contributing to the "throaty sound" we are hearing.

I'm very happy and satisfied with my Genesis and continues to love it each time I drive and watched people trying to figure out what kind of car it is, both on the highways and parking lots.

Solano, thanks. The 3.8 is continuing to amaze me. I am averaging 23.3mpg in driving that is about 2/3 highway, 1/3 city. The power delivery is smooth in all speed ranges. I have not yet encountered a situation where I felt I actually needed more power than this engine can deliver.

 

[DavidNJ]

A burbling sound can be intake or exhaust. Both have tuned lengths and in a modern engine are influenced by the variable valve timing. Some cars also have multiple or variable intake tuning.

What is the engine speed when it occurs?

 

[JimInNashville]

A burbling sound can be intake or exhaust. Both have tuned lengths and in a modern engine are influenced by the variable valve timing. Some cars also have multiple or variable intake tuning.

What is the engine speed when it occurs?

David, around 1900-2100 RPM. When the car is cold, especially, the burble gives way to something harsher, sort of like the sound that bike wheels made when I taped playing cards to them as a kid.

 

[JWO]

I just recently purchased the genesis coupe v6 and I'm hearing the the same sound... it's driving me nuts, has anyone figured out what it is?