Engine Starting 'Thump'

[nickpike]

Hi, when I start the engine, I hear the starter motor fire over a couple of times and then the engine fires-up. But there is quite a thump noise at start up, followed by the usual running engine noise. In my 3.3L Sonata (similar GDI engine), following the starter motor noise was just the normal engine running noise. The dealer says this is normal. Does every G2 sound like this at start-up?

 

[Ernie3647]

Didn’t know they even make sonatas with a 3.3 6 cylinder. Is that unique to your location? No my Genesis doesn’t make that noise. Ask to hear another one on the lot start up.

 

[MikeyTG]

I don't hear anything like a thump. Do you feel it as well as hear it? If so maybe a bad engine mount, allowing the engine to move too much and hitting something?

You also say you hear the starter motor "a couple of times". When I start mine I hear the starter for a split second and the engine starts immediately, every time. If it takes the system several tries to start then there is something wrong.

"The dealer says this is normal". This is the typical first line of defense for these skallywags. They will say anything to sell the car and then say anything to deny there is a problem.

 

[Seejay]

I hear a slight knock right when the engine starts up, but I am pretty sure that it is the timing chain. Time will tell.

On my 3.3 L V6 Sonata, the timing chain barely makes noise on startup, and I can only hear it on a cold start when the oil needed changing.

Nearly all engines with overhead cam timing chains (I can imagine that the chains on the Genesis engines are rather long) will make a noise on startup until the tensioner, usually run by oil pressure, will engage.

There have been some chain failures. One of the most important reasons to change the oil frequently is to minimize timing chain wear. A friend of mine who a mid 70s Mercedes with a straight six would change the oil when he started to hear the chain on a cold start.

 

[CanukV6]

Hi, when I start the engine, I hear the starter motor fire over a couple of times and then the engine fires-up. But there is quite a thump noise at start up, followed by the usual running engine noise. In my 3.3L Sonata (similar GDI engine), following the starter motor noise was just the normal engine running noise. The dealer says this is normal. Does every G2 sound like this at start-up?

I experience exactly the same thing with my car. I also reported it to the dealer and got exactly the same feedback. Doesn't seem to be a problem, but definitely noticeable.

 

[smirn0ff]

no such issues with my engine

 

[aminoacid91]

Yes, I hear a noticeable thump everytime I start my car, although the car turns on immediately. I have also wondered about this...

 

[Genentec]

its called the sound of moving parts. blame it on hyundai

 

[nickpike]

its called the sound of moving parts. blame it on hyundai

What does yours sound like? My Sonata 3.3L V6 (lovely, reliable car for 9 years) didn't make this noise.

 

[StarPower]

What you're describing sounds like piston slap. Some engines are designed with a larger clearance between the piston and cylinder wall when the engine is cold. This allows the piston to move slightly until the piston warms up and expands. It's very common in some vehicle, and generally isn't considered a concern.

Although the 3.3 may be similar to the 3.8 in many respects, the internal clearances may be different. You could try checking the other forums (1st gen and coupe) to see if they've experienced a similar noise on the 3.8.

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[ceebee]

I hear the same slight "thump" when starting but usually from a cold start. I also got the usual "It's normal" response from the dealer when I brought it to their attention. I could understand how it could be normal. It's a big V6 engine after all.

 

[Mark_888]

What you're describing sounds like piston slap. Some engines are designed with a larger clearance between the piston and cylinder wall when the engine is cold. This allows the piston to move slightly until the piston warms up and expands. It's very common in some vehicle, and generally isn't considered a concern.

Although the 3.3 may be similar to the 3.8 in many respects, the internal clearances may be different. You could try checking the other forums (1st gen and coupe) to see if they've experienced a similar noise on the 3.8.

I don't recall anyone complaining about a "thump" for the first generation Genesis 3.8. However, my first generation 3.8 engine starts quieter and runs quieter overall using Mobil 1 5W-30 or 0W-30, compared to a 5W-20 motor oil.

 

[jarred52]

After reading this thread, I really listened when I started my Genny today; there was a light thump when started. I had never noticed it before.

 

[Mark_888]

After reading this thread, I really listened when I started my Genny today; there was a light thump when started. I had never noticed it before.

Do you mind telling us what model year you have, or is that top secret information?

 

[Genesis5.0]

Mine does it every now and then. I have a 2015 V8

 

[jarred52]

Do you mind telling us what model year you have, or is that top secret information?

This site is for 2nd gen cars and my legend states that I have a 3.8. What else do you need?

 

[Mark_888]

This site is for 2nd gen cars and my legend states that I have a 3.8. What else do you need?

The information about you in the upper left corner of each post says:

jarred52
Registered Member
Drives a Hyundai Genesis 3.8 V6 Sedan​

If you have a 2015+ Genesis, you should have selected:

Drives a Hyundai 2G Genesis 3.8 V6 Sedan​

 

[Ohill]

Mabe the motor mounts are bad.