4G63 vs 420A for smoothness

[makriluc]

Hi guys. I know catchy title
My wife owns a 97 TSI AWD. We just purchased a 95 Esi with, yes the 420A motor, for our daughter. We really had a good price on the car.
And I know how smooth running is the 4G63.
Now the question, is the 420A as smooth running?
To me it does not feel as smooth. Else than the 4G63, I’m more experienced with 6 and V8s
Engine as 170 Km. Plugs and wires were changed (old plugs looked good). I don’t have any ECU codes. Compression is 145psi on all 4.
When idling it looks/feels like if it’s partly missfiring. When accelerating it does not “chug” but sound wise still like if it was partly missfiring.
Again my question is: is the 420A as smooth as the 4G63?
Thanks.

 

[flyinghighlm]

Yeah it is, I have a 92 GSX my room mate has a 95 sebring (420A) with crap on it and his idles better than mine at time, so yes if everything is in line and it should be just a nice as any other little 4 cylinder

 

[c4uldr0n]

my buddies 420A avenger holds its own, it does run very smooth, I think it idles better than my 4G63, but I'm not stock and he is.

 

[makriluc]

Thanks guys.
So, I should be concerned and start looking deeper.
Any advice (or maybe this is too vague) ?

Thanks again.

 

[420a-t]

As far as running, I'd say that the 420a is "smoother" at idle and low rpms as well. But, to me, the 420a's a/t shifts harder...although that could have been just my 420a.

 

[DSMcrazy3]

Compression was 145 all the way across on the 420a? That isn't a good sign. Do a leak down test to see if anything is uncovered.

Normal compression for good 420a would be about 180-210.

 

[makriluc]

Thanks DSMcrazy3.
180-210 psi compression !!!! WOW , I was not aware that it should be this high.
I did the compression when the engine was warm, wide open throttle, 5 turns on the crank.
Is this how you usually do your compression tests?

 

[DiamondStarAwd]

Yes.

n/a motors should run higher compression. 145 is loowwww for that. Thats a 1g turbo motor for ya.

 

[ThingyNess]

Yep, that's how you should do your compression test. 145psi is what you should see on a low compression 7.8:1 1g 4g63, not a 420a.