High mileage 3400 maintainance
 

So my 3400 has 231xxx Km(143xxx miles) on it and now that I have a full time job, I think it's time to look at the maintainance and preventative maintainance aspect of the engine instead of performance.

I believe The pre cat O2 sensor is still the original sensor that came with the car so I'm thinking of replacing because I remember when I was getting my car tuned a while back, the O2 live data graph had some flat spots and wasn't switching voltages like a fully operational o2 should be. To this day I still don't have any codes relating to a faulty o2 sensor, but i think it'll still help with my performance and gas mileage.

I know it's been a while since my PCV valve has been changed so that's something else to probably do as well. I pulled it out and shook it a bit and it wasn't freely opening and closing. It seemed a little sticky. Typically how often would these things need to be changed?

So far I've recently done AC Delco iridium plugs, NGK wires, magnaflow oem replacement cat, annual seafoaming. Other than what i've mentioned i'm not too sure where to go from here. These engines are stong and reliable and I want to see my Alero last me a long time before a engine rebuild is required so any input is welcomed.

Bump

Well have u checked the limg and the headgaskets. when is the last time the coolant has been replaced. also the tranny fluid. the pcv valve is easy to replace. water pump oil pimp
i just replaced my headgaskets and my car has 144,000 miles.

imo as far as your 02 sensor goes, if its not broke, dont fix it.
at work we recomend at 50k miles (after your 100k service we start over again):
air filter, fuel fitler, trans flush. if your coolant wasnt done at 100k it should be flushed, brake fluid flush (millage based), power steering flush (millage based).

hey jlw. i got back to you on shipping.

Tranny and coolant flush was done in May 2010, power steering return line had a leak that was replaced this week so it's new fluid and recently did the camaro front brake swap so its new fluid as well.

As for the o2 sensor, i'm just think that maybe it'll help a bit because I'm getting about 22 MPG on the highway and I thought I'd give it a shot.

Edit: as for fuel filter it was also changed in 2010, but I'm going to replace it soon again. And for the the air filter according to www.fueleconomy.gov some new study shows replacing a dirty air filter only restores power, not performance. I'm still going to buy a K&N cone filter to replace this shitty generic filter I have on my cold air intake. The MAF and TB were also cleaned this year as well.

i say a fuel filter and throttle body cleaning would do your car some good. also, a bottle of chevron techron fuel system cleaner has helped my car run much better between major system fixing and whatnot. when was the last time you changed your air filter?

also, is there any possibility that your car has a leaky vacuum line? i had one that was not setting a SEL light and after I got it fixed, fuel mileage went way up

but isnt power performance? if your air filters dirty it still effects the way your car runs. if its dirty enough your car could potentialy run like shit.

edit: i think the websites stupid..
"6. Replacing your air filter will help your car run more efficiently.
This is true for older vehicles with carbureted engines, but modern fuel-injected engines have onboard computers that automatically adjust the fuel-air ratio to the proper level. Changing a dirty air filter won't increase your fuel economy, but it might improve your engine's performance."

if the filter is dirty enough to effect performance then it obviously is effecting fuel millage.

I havn't check anything for leaks so far so there could possible be a vacuum leak, but my mileage has always been crappy since I started driving my car.

Just this past summer I bought a crappy Ractive air filter as a temporary solution for my cold air intake. Once spring comes, i plan on redoing all my intake piping and buying a K&N filter. I bought a 65mm tb and once it comes I'm going to buy a ported UIM and throw that on as well.

One thing I haven't done in a while is fuel injector cleaner. I've never had any luck with them anyways so I actually don't care for them.

I intend on buying the O2 sensor tomorrow and filling up and seeing what my MPG is like. I'll probably post my results if there was any improvement.

I also heard that the "winter blend gas" also has some sort of effect on mileage too so that could also be a contributing factor.

Sorry, I'm on my iphone and it's hard to proof read lol. Power and performance are used to describe the same thing, your right. I meant performance and fuel mileage. I'm not too sure on that study anyways because it's the first website I've read that actually says that.

winter blend WILL effect your engine a bit. its more explosive to help run in cold weathers iirc

I've always found that mine gets fairly poor gas mileage compared to most on here. I was luck enough to find not 1 but 2 leaks when I topped up my washer fluid. Yay!

i get 20mpg highway and ive done everthing i can think of..... i think my car just hates me :P

also nobody has said serpentine belt yet so what the hell SERPENTINE BELT

Have you done the MSD ignition coil upgrade? I've read phenomenal results from that. I'm getting ready to do it here soon. I also got MSD plug wires, so I'm excited to see any potential MPG upgrade lol

I know that the MSD coil mod is common on the 2.4 but i have not heard of anybody using the 3400.

The GM coil on the 3400 and the 3800 should not be messed with. GM makes the best coils out there. On HP they tested the MSD compared to the GM coils and GM came out on top. If your coils test between 5-7K ohms they are fine and should be left alone. There are guys making huge power in turbo 3800's using GM coils and are holding just fine

22mpg highway!?!?!?! wtf.....lol. I get about 33 mpg highway....25-26mpg city/highway...about 20-22 just city. You def got somethign wrong....the air filter doesn't matter as much....as long as you have the full intake any filter is pretty much fine...i have cheaper one on mine now and it runs fine.

This. ACDelco coil packs are next on my list.


Lucky bastard. I didn't think my mileage was that bad lol.

I'm with billy. I get about 31-33 on the highway and I haven't done shit to mine, (other than the cat-back). Keep in mind, just because there is no SES light, doesn't mean there isn't anything wrong. Our computers have codes that won't throw the light. Take it to a GM dealer and have them hook it up. It's only around 80 bucks, and if you can fix it after that, it will pay for itself in fuel money you save.

If not been done before it would be over due for timing chain replacement

Same here never got good mileage with this car for the past 1.5 year but i mostly do city drive ~85% of the time (~300 km per tank :eek:) betwwen 75-85km for 1/4 tank in summer & about 65km for 1/4 tank in winter

Never changed any of my sensors as it never got any engine light on until recently about 3 weeks ago

I get like 12 mpg dont feel bad