Vibration at low RPM on 2001

[cesarcoral]

I just went to a dealer to look at a 2001 NSX with 9,110 miles on it.

Turned it on and the idle was extremely rough between 850 and 1500.

At 2000 and up it was ok.

The whole car shook when the idle was rough.

Anybody experience this before?

Thanks.

 

[hlweyl]

It is normal for the NSX to idle a little rough at low rpm, but for the whole car to shake... maybe something is wrong. Maybe a bad motor mount, just a guess.

I would suggest sitting in another NSX to compare.

 

[TRM04]

To an extent, a rough idle is normal on this car. I too was alarmed by this but laid that concern to rest after feeling that same rough idle in other NSXs.

 

[cesarcoral]

To an extent, a rough idle is normal on this car. I too was alarmed by this but laid that concern to rest after feeling that same rough idle in other NSXs.

Would it be rough enough to shake the car and steering wheel? The whole thing would shake, sitting still.

 

[NSX-Racer]

The car may shake when engine is cold and idle is about 800 rpm (but that would be a malfunction because idle is automaticaly raised when the engine is cold). It should not shake if it's at 900 or higher with warm engine. If that disturbs you there's a procedure to raise the base idle. You may do a search in this forum with the words "base idle". It has been described here.

 

[ImolaOrange03]

I just purchased a 2003 NSX with 14,000 miles on it. There was rough idle during warm up at 1300 rpm and calms down a bit once it went down to 900 rpm. When I step on throttle to get 1300 rpm, I got the rough idle back.

I took the NSX to a Acura dealer and the Acura Sr. Tech at Acura Headqtrs said that the rough idle is normal. Said that if I removed the Targa top, the roughness during idle will be less. Anyone else experience this?

 

[Gansan]

I just purchased a 2003 NSX with 14,000 miles on it. There was rough idle during warm up at 1300 rpm and calms down a bit once it went down to 900 rpm. When I step on throttle to get 1300 rpm, I got the rough idle back.

I took the NSX to a Acura dealer and the Acura Sr. Tech at Acura Headqtrs said that the rough idle is normal. Said that if I removed the Targa top, the roughness during idle will be less. Anyone else experience this?

That vibration you feel just above normal idle sped (1200 rpm or so?) is just a result of the engine's characteristic mechanical vibration and not misfire. It's a 90 degree v6 rather than the more balanced 60 degree. Personally, I like the shudder that you feel in your back when you blip the throttle through that range--it is part of the NSX's character.

 

[Tom239]

Can anyone offer an explanation as to why the NSX has a 90° V6
rather than 60°? That is, what are the advantages to a 90° engine
in this application?

 

[Gansan]

Can anyone offer an explanation as to why the NSX has a 90° V6
rather than 60°? That is, what are the advantages to a 90° engine
in this application?

A 90 degree angle puts the heads lower, resulting in a lower center of gravity. That would be the engineer's answer. A more pragmatic and common reason would be they already had a V8 with a 90 degree bank angle and they wanted to reuse the design for a V6. This results in engines like the venerable Buick 3.8L V6 (not bad, but it has a characteristic vibration at idle). It's also possible they had packaging reasons, such as a requirement that the engine had to fit under the low hood of the first generation Legend. A wider angle would make the engine that much shorter.

I don't know Honda's particular reason for the angle they chose.

 

[tunlhd1]

I noticed a "rough idle" on the 2003 I recently purchased with 12k miles. It only happens when the engine is cold and goes away once the engine warms up. I did not have this issue on my 1997 NSXT.

 

[BD]

I had some vibration problem as well. The throttle body on my 03 had some problems, the car idle at 700 rpm (instead of 800/900) and often stalled while braking. The dealer installed a new one for me, and most of the vibration issue went away. It is still a little rough, but much better than before.