V8 cold start vibration

[asterix]

Hi All,

First post to this forum! I am a happy owner of an '09 Genesis 4.6 with Tech Package. We just took it on a nice long trip and the odometer just ticked past the 1,000 km (620 miles), so the engine is just starting to break in. We love everything about the car, except for one little nuisance. When firing up the engine, the engine (and car) vibrate considerably. We have had V8's before, but never encountered this. Went back to the dealer who mentioned that this is “normal behavior” due to stricter emission controls. We checked out other V8's on the lot and they exhibited the same. Once the engine warms up, it runs as smooth as butter. The vibration seems to be worse now that it is getting colder at night.

I found a post regarding the air intake temp sensor, and was wondering if this is related to the air intake temp?

http://www.genesisowners.com/hyundai-genesis-forum/showthread.php?t=2268

So, my question is, is this indeed normal behavior? Does it indeed get worse as it gets colder? Is there something that can be adjusted?

Many thanks in advance for any comments/suggestions!

 

[Sayantsi]

Did the dealer happen to state what caused this behavior in all V8s?

 

[DesertGen]

There is a noticeable vibration for the first few minutes after I start my car, then it smooths out, just as you say. Doesn't seem to be a problem but I have had smoother running engines, even with fewer cylinders.

 

[asterix]

Hi All,

I found out what is causing the vibration during the cold start of the 4.6 L V8. Today I talked to a good friend of mine and we were doing some car talk. I explained to him how we love the Genesis but that I was a little surprised that an award winning engine would vibrate like this during a cold start, only to run butter smooth after warming up.

Turns out it is completely normal and caused by...

Closed loop cold start retard spark control using ionization feedback

This will help reduce the carbon hydrate emissions by heating up the catalyst much faster. The spark time retardation is causing the vibration!

If you Google it, you will find a few patents of the technology!

Who knew...

 

[scottdk]

Hi All,

I found out what is causing the vibration during the cold start of the 4.6 L V8. Today I talked to a good friend of mine and we were doing some car talk. I explained to him how we love the Genesis but that I was a little surprised that an award winning engine would vibrate like this during a cold start, only to run butter smooth after warming up.

Turns out it is completely normal and caused by...

Closed loop cold start retard spark control using ionization feedback

This will help reduce the carbon hydrate emissions by heating up the catalyst much faster. The spark time retardation is causing the vibration!

If you Google it, you will find a few patents of the technology!

Who knew...

One hell of a good post asterix! Thanks for the info

 

[BorregoV8]

NONSENSE!!! There is a Service bulletin on this issue. The KIA TAU owners are having the same issues read below sound familiar? Find a new Dealer one that knows what they are doing! Insist on the Dealer to have a service zone rep inspect your car. My V8 is smooth as silk at idle yours should be also!



Make : KIA Model : BORREGO Year : 2009
Manufacturer : HYUNDAI-KIA AMERICA TECHNICAL CENTER INC
Service Bulletin Number : TSB-046 Date of Bulletin : MAY 01, 2009
NHTSA Item Number : 10030365
Component : ENGINE AND ENGINE COOLING:ENGINE
Summary :
KIA MOTORS: RELATING TO OIL CONTROL VALVE (OCV) USED IN CONSTANT VARIABLE VALVE TIMING (CVVT). IF AT ANY TIME OCV IS SUSPECTED AS A CAUSE OF ROUGH IDLING, POOR ACCELERTION, CAMSHAFT TIMING MISALIGNMENT RELATED TROUBLE CODES, MISFIRE RELATED TROUBLE CODES ETC., ON THE VEHICLE EQUIPPED WITH THE CVVT SYSTEM, BE SURE TO PERFORM THE OCV INSPECTION PROCEDURE BELOW BEFORE REPLACEMENT. NO MODEL YEARS SPECIFIED. *PE

Check to Request Research. Submit below.

 

[asterix]

BorregoV8, if you read my original post, it says that the engine runs smooth as butter once it is warmed up. DesertGen confirmed the same behaviour in his car. I was just wondering if this was normal and if other V8 Genesis owners experienced the same.

The explanation given to me makes perfect sense and explains that due to today's stricter emissions control, the engine is using the described method to heat up the catalyst much faster, thereby reducing the carbon hydrate emissions.

I have a feeling that the Service Bulletin that you are referring to, is dealing with rough idling, misfiring etc. Nothing specific to cold starts.

 

[BorregoV8]

BorregoV8, if you read my original post, it says that the engine runs smooth as butter once it is warmed up. DesertGen confirmed the same behaviour in his car. I was just wondering if this was normal and if other V8 Genesis owners experienced the same.

The explanation given to me makes perfect sense and explains that due to today's stricter emissions control, the engine is using the described method to heat up the catalyst much faster, thereby reducing the carbon hydrate emissions.

I have a feeling that the Service Bulletin that you are referring to, is dealing with rough idling, misfiring etc. Nothing specific to cold starts.

Except for a light knock at start up I have NO vibration when cold or first started.