3.4 or 3.8L engine

I've been looking at some Impalas in the 03, 04 year range. I see a lot of them were made with 3.4L engines. I am a little familiar with the 3.8L engine, but not so with the other engine. My question is how do the motors compare and would it be wise to choose one with the 3.8L or what?
The engines aside is this a good reliable car or is it one to steer clear of?

Thanks in advance

I think the '03-'04 Impala is a very reliable and durable car. The problem with the 3400 engine is the lower intake manifold gasket leaks and will have to be changed. The 3.8 would probably give you less problems and be a better choice.

Thank you.

The 3.8 also gets basicly the same gas millage as the 3.4, but has 20HP more.

speaking of fuel economy what could one expect with the 3.8 in this car. The car I was looking at originally(equipped with a 3.4) claimed to get 39mpg. on the sign. This I found a little hard to believe.

I own 3 Impalas with the 3.8 engines and consistently get in the upper 20's in mpg. I (we) love the ride and comfort of the cars, although the jury is still out on reliability. My sons 03 ok now, but a very rocky start, my daughters 02 has been fine, my 03 has given me nothing but problems. All three cars were purchased used.

speaking of fuel economy what could one expect with the 3.8 in this car. The car I was looking at originally(equipped with a 3.4) claimed to get 39mpg. on the sign. This I found a little hard to believe.

Well, that must have been a typo! 29mpg maybe, altho these engines are really good with gas. My 05 Malibu has the 3.5L Engine and is rated at 28city/32hwy and when the gas was really high I was able to squeeze 34mpg under mixed driving, but the body on the Malibu is way lighter and smaller than the Impalas. So I think that 39mpg figure is way off.

The 3.4 gets the better fuel mileage and that is what I have been hearing.The 3800 series II does have a few problems,the upper intakes which are made out of plastic splitting around the EGR port area and filling up the intake with water shutting the vehicle off making it not start.The oil pan gaskets are a flaw too which leak,with the steel oil pans.

I've got an '02 with the 3.4 bought brand new and I've always been able to get 500 miles to a tank on the interstate running non-stop. Mine also had the leaking lower intake gaskets, but no other problems otherwise over 7 years and 122k miles so far.

Even with my transmission problems (Not going into 4th when it feels like, or the TC not locking up) I still get 19/20 City, and 29/30 Highway.

I've heard of the Intake manifold splitting by the EGR, but they've had a metal sleeve or something in that area to prevent that for the last fear years of production IIRC.

110,000 Miles on my 3800, only thing I've had done is the Intake gaskets done 14,000 miles ago (3800s suffer from Poor Gasket design too, but not as early/often as the 3400s).

Well, that must have been a typo! 29mpg maybe, altho these engines are really good with gas. My 05 Malibu has the 3.5L Engine and is rated at 28city/32hwy and when the gas was really high I was able to squeeze 34mpg under mixed driving, but the body on the Malibu is way lighter and smaller than the Impalas. So I think that 39mpg figure is way off.

I have 05 Impala with a 3.4 and on normal driving get 36mpg, it all depends on how you drive a car and what you use in it.