impala 3.4 vs 3.8

hi i want to buy a 2001 impala 3.4 l
i was told that the 3.8l was much better and had less problems...now i dont know much about cars can someone tell me what the 3.4l motor has in terms of problems...
thankyou so much!!!
noemie
xxx

hi i want to buy a 2001 impala 3.4 l
i was told that the 3.8l was much better and had less problems...now i dont know much about cars can someone tell me what the 3.4l motor has in terms of problems...
thankyou so much!!!
noemie
xxxthe 3.4 is a better engine they only had problems with the head gaskets in 2000-2003, the 3.4 is lot smother,better on gas and can keep up side by side with a 3.8 on the highway,we have the 3.8's in our police crusiers and they keep blowing up

The 3.4 have problems with intake gaskets also.Fel Pro makes metal intake gaskets for them in place of the plastic intake gaskets.They are more money than the plastic ones and are a lot better.The 3.8 has has problems with the upper intakes and most parts stores stock them.

3.8 is a hundred times better. 3.4 sucks in every way. Weak at all speeds, noisy, coarse at speeds above 3k rpm, known oil and coolant leaks, mainly due to bad intake gaskets and often times head gaskets. It also doesn't get the greatest gas mileage. Occasionally, it can start really hard too.

The 3.8 is definetly more powerful, enough for a car as large as the Impala. Its smooth at all speeds, great on gas, completely reliable, and cheap to maintain. The only thing that can go wrong is the upper intake.

I bought a used 2003 Impala...3.4...and it is VERY VERY strong and fast.

I have built up a few hotrods...my last was an IROC Z that I put a PAXTON SUPERCHARGER setup on.....so I know what speed is..

My Impala...is so smooth at ALL RPM ranges....and handling is awesome....and the quick jump off the line...is unmatched...in it's class.

I think the problems that have been spoken of here come mainly from ABUSE of the cars..and LACK OF MAINTENANCE...which will happen in any model car.

You must take care of your ride..and your ride will take care of you....!

THE 2003 IMPALA is an awesome car.....for the money especially...!!! :iceslolan

Every 3.4 built through 2003 will experience gasket problems that can lead to major engine problems if not taken care of rapidly. Most 3.8's will also have similar problems. However, all in all, the 3.8 is a much more reliable and durable motor. While most 3.4's will never make it beyond 120k miles, the 3.8 is generally good for 200k+ miles.

I don't know what 3.4 you are talking about, but smooth and powerful do not apply. Perhaps if you are comparing it to an 80's car or a 4 cylinder, but no way is it even close to being as smooth or powerful as most modern motors. The 3.8 is one of the best for smoothness (though occasionally it can sound loud at redline) and has great power up until about 90 mph, at which point it no longer will pull quite as strong.

whatever... my Impala ... is strong and works like a charm ...you think I'm dreaming or making this up...give me a break.

If you don't like the car... go on down the road....I'm telling you...the engine is STRONG..and .... the power is clean and strong throughout the RPM...range..

My car is WELL maintained.... and strong...

to each his own.....:banghead:

:runaround:

Every DAY...I'm leaving all makes and models behind....quick takeoff...good gas mileage..... strong. pulll of the line...

hey I know what.... bring on whatever it is you are driving...and meet me at the stoplight...OK...

Put your money where your mouth is...

:screwy:

:iceslolan

Every 3.4 built through 2003 will experience gasket problems that can lead to major engine problems if not taken care of rapidly. Most 3.8's will also have similar problems. However, all in all, the 3.8 is a much more reliable and durable motor. While most 3.4's will never make it beyond 120k miles, the 3.8 is generally good for 200k+ miles.

I don't know what 3.4 you are talking about, but smooth and powerful do not apply. Perhaps if you are comparing it to an 80's car or a 4 cylinder, but no way is it even close to being as smooth or powerful as most modern motors. The 3.8 is one of the best for smoothness (though occasionally it can sound loud at redline) and has great power up until about 90 mph, at which point it no longer will pull quite as strong.I have 12 friends here where i am living with same car with the 3.4,8 of them are taxi drivers using the 3.4 and as for the engine not making it past 120 km's,bull, they have anywhere fom 350 000 km'sto the last one having a 620 000 km's and that impala has been on the rd since 2000 when they first come out,not only that we get six months on harsh winter with temps going as low as -35 to -40 in newfoundland

whatever... my Impala ... is strong and works like a charm ...you think I'm dreaming or making this up...give me a break.

If you don't like the car... go on down the road....I'm telling you...the engine is STRONG..and .... the power is clean and strong throughout the RPM...range..

My car is WELL maintained.... and strong...

to each his own.....:banghead:

:runaround: Ya i agree with you,the only people who have the impala with the 3.8 shoot the 3.4' down because they have'nt had one

Well, I might as well join the fray...I have had my 02 imp 3400 for 2.5 years. 61k at purchase I have put 12k on it in that time and had (0) engine problems. It is plenty strong for my taste, but then I am 58 so the younger guys may want more as the 3.8 does have....I am sure they are similar in maintenence costs as far as oil and coolant needs, and tuning. Regular oil and filter changes, and coolant every 2 years, trans filter/oil 60k intervals will keep you on the road with either engine you choose. I have had to replace the battery, rotors and pads 65k...one wheel bearing front, and plugs and wires......Oh, one windshield....and one coolant flush and refill and one air filter and one cabin filter (under pass side cowl). Nothing there you couldn't have with any make or model car on the market in todays offers. The only complaint I have is the noisy valve train and not so great in town mileage. In mileage disscussions in this forum it is said many times the 3.8 does better in this category....but driving habits play a big role in these claims and for sure determination is not possible in this matter.

As for the comment about taxis, I believe any Impala that was ordered with the Taxi or Police package included the 3.8 and an HD transmission + HD suspension, despite having the base Impala looks.

As for those of you who think the 3.4 is so great, go drive a 3.8 and it will knock you to the floor. I owned a 3.4 (Venture) a few years ago and currently own a 3.8 s/c (Grand prix) and the difference in refinement and power is incredible. But that's comparing apples to oranges. I've driven many 3.8 naturally aspirated vehicles, including several Impala LS's. The 3.8 is hands-down one of the best engines ever made. The 3.4 is a real crappile in comparison. Trust me. I've driven them both alot. I know. I also see in daily life the miles that 3.8's can put on, whereas 3.4's won't last nearly as long.

As mentioned above, a vehicle will usually last as long as the maintenance and timely repair will take it. That said, the 231 Buick V-6 is probably the best all-around V-6 ever made. It has been in use since the mid '60s in everything from sports cars to sedans to Jeeps to vans to commercial engines. The rotating assembly is massive for it's displacement, the valve train is bullet-proof (not so easy to say about the 3.1/3.4L Chevy V-6), the block has superior web design between banks, and the wider main journals (15mm vs. 23mm) spread out the forces over a larger area, making bearing life far superior. As a result, they don't suffer the notorious piston slap and rod knock that so many of the Chevy V-6s do. They have also been boosted to levels that would shred the block on the 3.1/3.4L Chevy engine, namely in Turbo Buick like the GN and Pontiac TTA, and to even higher levels of power by custom builders. They seem to get along just fine making 500 HP, where the Chevy V-6 would not last long at that rate.

Again, for a normally street driven engine, timely maintenance and repair should take either to very high mileage, but the Buick just has the design which makes it inherently more stable and robust, giving it a distinct advantage in survival.

Blue Bowtie, Very well written and easy to understand. Thanks for the post and for mentioning the idea here for the most part, concern is for the street use vehicle. Kudo's from Southwest OH....!

IMO most of the 3.8 i know of wih propper care go well over 150k

Both engine are great, I like the 3.8l. But other than the intake gasket issue the the 3.4L is also a winner. The car is a good choise.

As for the comment about taxis, I believe any Impala that was ordered with the Taxi or Police package included the 3.8 and an HD transmission + HD suspension, despite having the base Impala looks.


You are only half correct. The 9C1 and 9C3 Impala police packages do have the HD suspension, including the tubular rear trailing arms, but they do not usually have the 4T65E-HD transmission. As far as I know, the only difference between the regular Impalas and the police packages, transmission-wise, is that most police packages include the 3.29 transmission drive ratio. The supercharged Impalas (Impala SS) do have the 4T65E-HD transmission however. One way to find out which transmission the car has is to look at the RPO codes in the trunk. M15 means 4T65E, MN7 means the 4T65E-HD.

As far as the 3.4 versus 3.8 engine goes, I would probably suggest going with the 3.8. My fiance's 3.4L 2002 Oldsmobile Alero (79k miles) is currently experiencing the dreaded lower intake manifold gasket leak, while my 2004 Impala (9C1) (81k miles) with the 3.8 engine does not have that problem. Additionally, that extra 400 ccs of displacement will get you a bit more power with a fairly insignificant drop in fuel economy. As someone already mentioned, however, the LIM gasket issue was fixed in 2004 I believe. If you still decide to go for the 3.4 engine and the gasket does fail, it's not that difficult to replace if you are somewhat mechanically inclined and have a decent set of tools (especially torque wrenches). It will set you back by about $150-200 and 6-12 hours of your time.

Fel Pro has the fix for the intake gaskets,came out with ones made out of metal instead of plastic and are more money if you want to do it once.I have done this once and I do not torque the intake bolts.I run them down with a 3/8" impact wrench and there is one problem with torqueing the intake bolts.Most over torque them and do the job all over again.The 3.8 series II is a bullet proof engine and the only problem is with the upper plentuim.It is made out plastic and will fill the intake with anti freeze and will cause a no start if not caught in time.I read in my local paper about one mechanic hating the Impalas as police cars putting in more money for repairs putting in transmissions,axles and other suspension parts.

I purchased a 2002 impala LS with 250,000 miles on it. Last week it rolled over 260,000 with no problems at all. I'm very impressed with the power this engine still has with all of those miles. And it doesn't burn or leak any oil. A very good car.

Great forum! Buying 2004 Impala 3.4, 50K on it New tires and brakes (rotors too). What type of maitenance should i look to do at this point coolant, tranny. What about intake gasket? Can I check it? Runs great... I took it on trade at work and hit the trip computer said 31.8 mpg, to me that is great for such a large car. Looking for any pointers as to what I should look to do to it. Driving to FL. from OH in a month want it in tip-top shape.

i own a 2002 impala 3.4 and my buddy has a 3.8 impala ls and we have the same mileage almost 180,000 miles! all you have to do is maintain your vehicle like your suppose too i have never had a check engine light he has 4 codes on his check engine light! we have raced each other at gateway track at and open and we stayed neck to neck until his car wouldnt let him go any faster. we both get 29 mpg on the highway. the only differences with the engines are the the 3.4 engine are mostly aluminum so if you do not maintain up to date you will have problems but its that same with every vehicle! i am not an impala enthusiast but i am telling you that i love cars and hondas and other "long lasting cars" cant compare you end up putting more money into it! the only reason they do not make the 3.4 or 3.8 anymore is because they could not keep up with emissions, i also know multiple people with impalas with 250,000 plus with both engines they are pretty much the same engine besides bracket and and cooling set up. all you have to do is flush your coolant change your oil flush your transmission fluid change your thermostat and timing chain and you will be fine!

i own a 2002 impala 3.4 and my buddy has a 3.8 impala ls and we have the same mileage almost 180,000 miles! all you have to do is maintain your vehicle like your suppose too i have never had a check engine light he has 4 codes on his check engine light! we have raced each other at gateway track at and open and we stayed neck to neck until his car wouldnt let him go any faster. we both get 29 mpg on the highway. the only differences with the engines are the the 3.4 engine are mostly aluminum so if you do not maintain up to date you will have problems but its that same with every vehicle! i am not an impala enthusiast but i am telling you that i love cars and hondas and other "long lasting cars" cant compare you end up putting more money into it! the only reason they do not make the 3.4 or 3.8 anymore is because they could not keep up with emissions, i also know multiple people with impalas with 250,000 plus with both engines they are pretty much the same engine besides bracket and and cooling set up. all you have to do is flush your coolant change your oil flush your transmission fluid change your thermostat and timing chain and you will be fine!
Well said. The problem with maintaining vehicles is many people are lazy. It's work to do all that stuff year after year. I have a '98 Pontiac Montana with the original 3.4 and it is very reliable. I did the intakes before they failed. It will easily go 200K and beyond. I believe the engine behaves the same now as it did the day I bought it. The trans is solid. I love flooring it every now and then and watching passenger's eyes light up.

i have a 03 3.4 impala and i really dont like it. i have had it a little over 3 years and still paying for it. i have had nothing but trouble out of it. it has been maintained well it just doesnt do well for me. within a month of having it i figured out it vapor locks. yes i've been told its impossible for it to vapor lock but that's a load of bull. i've figure ways around it like not tightening the gas cap but after awhile it throws my check engine light on. it seems like everytime i fix something on it something else goes wrong. like now i have to change the timing chain on it... always something going wrong with my car=( BUT anyone that i know that has one does good for them. so maybe i just got a jacked car lol idk.

I had a 2005 Impala with the 3.4 motor in it. It made it to 170K miles before it started leaking oil and the sweet smell of coolant. Had the original serpentine belt and the oil changed every 5000 miles. Never had a tune up and I had the car since 19200 miles. It served me well. I now have a 2012 Impala with a 3.6 engine. 300 horse and runs like a dream.

never knew about the impalas but mechanic had one to replace another car of mine that went out. i knew there were 2 engines for the 2002 and hoped for the larger one, but it had a 3.4.

when i took it for a test drive i was pretty stunned at the quickness. the difference was 20hp less than the 3.8, but the 3.8 had 300 more pounds, so it wasn't that much of an advantage.

in calif you can't do any real engine mods, but i put lower profile tires on and then lighter wheels that saved 10lb per wheel (unsprung weight) for 40lb.

this would definitely beat a stock 3.8 2002 impala now, and beats anything else on the road except plain out muscle cars. has 195,000 on it.

not saying it's the most amazing car in the world, but way up there in speed over anything i've pressed the pedal on in the other lane, or that i was driving. not to mention the handling is nice with 55 profile tires. not a street racer, but when i want to punch it, it wins, so i'm happy.

johnny,
Welcome to Automotive Forums.. just a little heads up/reminder; kind of watch the date/timeline (i've missed it once too), but you a replying/responding to a ten plus year old posting..
but your post is VERY correct: that power-to-weight ratio helps in every way, shape, and form.. by dropping the OEM steelies with the satin covers you actually probably shed closer to 14lbs. per corner with the weight of wheel+rubber+psi/air; and the lighter rotating mass the trans has to push..the lower profile is also assisting with mpg and drag coefficient, with a lower center of gravity..
plus you are also right about the bigger engine means nothing, if it weighs the nose (and overall total) down more w/o more HP and TQ to pick-up the same vehicle..
as far as being in cali (a VERY restrictive state for modders), that is still the home of speed/racing.. many aftermarket performance companies make E.O.CARB exemption components.. plus; even if not going all out, you can custom build your own CAI for less than brand names, or just buy better than AC/Delco for your regular maintenance items: wix, purolator1, or mobil1 instead of fram; plug wires: AC are good for 75-85K, but Taylor makes a great 8mm that fits in the GM 7mm wire holders and deliver more spark, so more hp or mpg (depending upon which way you use your pedal), etc.etc..
i have an 06 MAXX with the 3.5, and it is at 180k and still getting 32mpg; so you could easily see 275K on your impala with minimal maintenance..
and hey, at least L.A. is still above freezing and two feet less of snow than here!ha..
enjoy the streets and the Forums..

thanks ctesla...appreciate it.

for information, should i not have made a comment due to the age of the thread? if so i would have missed your input, which i appreciated. wish to know for the future. thanks

hey JJ,
i do not know if it is a rule, but i did see a moderator or administrator comment on something like "...45 days is considered a 'dead' thread.."
still, it is great you posted, as, i saw it as a red check on a new Chevy post (but i have such slow internet, everything is new by the time it hits my computer; even stuff posted a day old, haha) and read and replied..
most common/courtesy guidelines are here:
http://www.automotiveforums.com/vbulletin/guidelines.html

but when you start a new thread, you can 'quote' or reference a previous thread..
and when you do start a new thread, you can always post pics of your car; or a component that needs identified, or a replacement item, etc..
and i just wanted to let you know, as starting new threads allows others to see it and gravitate to it; i hope this helps.. enjoy the forums; i just got back to them after a long AFK in a military third world deadspot... now, i'm just waiting for snow to stop falling in colorado, so i can actually go wrench on something..

thanks for the info Ctesla...appreciated.

and welcome back!