Replacing Engine

My 3400 overheated and died so i'm getting a new (used) one put in. I found one for a thousand bucks, but i want to make sure of something first. Since i'm gonna have a vacancy in my engine bay, is it possible to just drop in a GAGT engine instead? I know i would need the PCM for it, but what i'm really concerned about is the gear ratios. Would the original Alero tranny accept the GAGT gear configurations, or would the GAGT tranny be needed for that swap.

[Wildman]

In this case, it's not the engine out of the GAGT that is the issue. You would need the tranny out of the GAGT as well as computer. Even at that, I dont know that you would be able to just drop in a GT computer in the Alero. Depending on years and other factors, there are differences im sure.

so why are you replacing your engine? did you crack the block? seize up the engine? if not, then just have the heads resurfaced for $50, get new gaskets $75 and install them and then be done with it.

what made you overheat if i may ask?

ANY 3400 will match up to your tranny, there is NO differences between how it mounts between any vehicle that came with the 3400.

and even if you do need to replace the engine, DO NOT pay $1000 for one. get one from www.car-part.com and in your local area and save A LOT of money.

with any "used" engine, i HIGHLY recomend replacing the head gaskets and intake gaskets at a minimum.

I was coming back from work and the water hose/pump rutured and the engine overheated before i could take care of it. The guy said the the rings were fried, so yeah, basically the engine seized up. And sad to say, a thousand was the best deal i could do locally, and the car wont be done til next Wednesday or Thursday, which really hurts my work being my daily driver. Sourcing out an engine and having it shipped here would take more time than i can afford. And to get the GAGT PCM would have been no problem, but i knew the tranny might be an issue.

are you positive the rings are bad? seriously, ive overheated worse than that twice and i know of two other guys that have ran dry on collant and not seized the engine.

its HARD to seize the engine.

if you can rotate the crank pulley, the engine is fine and you need to have your heads resurfaced.

im thinking your getting raped in the butt.

oh yea, i forgot, and engine swap should only take 2 days.

and if you want to sell the "junked" engine from your car, i would be more than happey to take it off your hands if you would like to ship it.

Originally posted by germ@Jan 31 2005, 10:07 AM
im thinking your getting raped in the butt.

Probably right, but i honestly don't know jack about engines. And he's my dad's mechanic and who he trust, so i kinda had no say so. And i thought a whole week to drop an engine was a little long, too. If you want engine, just give me a "feasible" price cuz i have no idea how much an "apparent" non-functioning engine goes for. Hell, you could make something up, but as long as the shipping cost don't out way the benefit of selling it. I have to pay this money back to my dad and has put my apartment back for months. <_<

[kwhauck]

you are probably getting ripped.........i was in the same situation....engine wasn't "blown" but so many gaskets were bad that it was cheaper and more cost effective for me to get a used engine (plus i got a beater car this last winter in trade for my old engine which i kept around)..............you need to look around more.....i picked up a 99gagt engine with 9k for $350........i had to drive like 500miles to pick it up though........worth it IMO........whatever you decide, do your research, look at all options, and ask a lot of questions......

^^I think the guy doing the repairs knows how bad i need this engine, and of course, when something is in demand, expect a jacked up price. And your advice is very valid, but i missed worked today because i had no ride, which leaves me very f'ed up situation. So i gotta skip being a "frugal shopper" and move right along to "compulsive buyer".

So keeping your old engine around can be beneficial, huh? And you didn't have any problems mating the GAGT engine/PCM to the Alero tranny?

[kwhauck]

everything went together fine......me and a buddy did the swap in a day....

why do you need the GA PCM and tranny?

you only blew the engine. no need to do all that tranny crap and pcm issues.

and i dont know if the GA pcm will work or not. it really depends on the OS of the PCM its self, and i will almost gaurantee that not all PCM's between the GA and Alero are the same.

[springs fastest alero]

I'm sure it doesnt take the guy a week to do the engine but he prolly has other work scheduled as well.
1,000 for an engine swap is a fair price but what all does it include?
if thats just motor and labor its still reasonable.

i do engine swaps all day for my full time job.
doing a used motor on a alero can easily be done in one day if your not replacing any gaskets or anything.

[-Alero-]

didnt someone say you can get almost brand new 3400s for under 600$

Germ - I thought i remember hearing that the final gear in the GAGT tranny was different than ours, so the PCM from the GA would be needed to properly shift the car in the correct shift points. I was incorrect to say the GA engine was needed, but i thought the PCM was a necessity.

Springs - it's not just the motor, but all the components that go with the car. I couldn't tell you the technical name for all the stuff, but all the parts that go along with the part are included in the price also. Now that i think about it, the engines are cheap like 99's because he installed the new engine using the original components. Everything under my hood is being replaced.

i will never claim to know a lot about the 4t40 and 4t45, but im pretty sure the difference between them is the FDR

however, im not really sure that the Grand Am PCM will be a direct "plug-n-play" thing.

there are quite a few different Grand Am PCM versions. look how hard it is for the GA guys to get a good DHP PCM. its because there are quite a few PCM versions running around and they do not "cross reference" with any of the other versions.

so just beware. im not sure if anyone else has just "slapped in" the GA PCM's or not to the Alero, but the IMO the likelyhood of it working without issues is slim.

and NO, you shouldnt "need" the GA PCM, however, if you are going to put in the other tranny, i would suggest you get ahold of DHP and have them flash YOUR pcm to match with the tranny your putting in, IIRC the only difference between the 4t40 and the 4t45 is a gear change. so its not that hard to modify a stock PCM to accept a gear change.

hell, you could probably get some type of "add on" connector to your tranny that modifys your rpm/speed sensor, or i think there might be some type of ring gear that you change over that will allow the pcm to work with the other tranny.

but like i said, im no expert on the 4t40 or 4t45 trannys, just know what ive read on here, gagt.com, 60*v6.com, and a few other places.

good luck though.

hope this clears up things about the pcm a little bit ...


what your saying is similar to me taking any Grand Prix w/ a 3100 PCM and putting that into my car.

it will not work

the "internal mapping" is different by just a tiny bit that will allow the car to run, but not drive properly. there are difference between the years and updates to the software that is used within the pcm and differences between models (ie. GT or SE).

basically what i am saying is that the GA SE has the 3400 w/ the 4t40, and the GA GT has the 3400 w/ the 4t45.

their pcms are different to a point that even the same model year GA's could not interchange the PCM and tranny to work.

the wiring harness is more than likely what your be messing with in order to get the pin outs to match up correctly so you dont fry anything.

[mike2002]

all the 3400 cars have the 4t45, grandam or alero, its the 4 cylinder that has the 4t40

it is correct that the gagt has a 3.29 fdr, grandam se's and alero's have 3.05 (3400's). otherwise, they are IDENTICAL engines and transmissions. the so called h.o. engine in the grand am gt is because of the BS "ram-air" that doesn't do anything, there only a little faster because of the transmissions fdr.

a grand am pcm wont work in a alero, there are differences. this is evident in the fact that a grandam SE's dhp pcm will not work in the alero according to dhp, even though everything in the cars is the same. most likely things like gauge/hvac that are different.

if you wanted the gagt transmission for its FDR you just need your oem pcm re-flashed by dhp, or buy there powertuner software.

the engine's can be had for $350-$450, but i guess the other 600ish is for installing it...I personally have no idea whats involved in that, or how long it would take, but according to them^^^^ its not to bad if you have some help.

I had a feeling it was more complicated than what they were making it out to be. No offense, guys. I just knew from what i knew about the GAGT, it wasn't identical to the Al. Thanx for the clarification, mike.

[kwhauck]

a gagt pcm will work.......mike (sc/alero) ran a gagt pcm in his car this summer (i'm pretty sure all it did to him was throw a code...)

as far as the engines.........it is that easy......i bought a 99gagt engine with 9k..........put it in in one day.......easy as that..........