NOOB needs some help!!... northstar blown!!!

2136 Views 15 Replies 8 Participants Last post by zonie77, Oct 18, 2005

1994transam

Discussion Starter · Sep 29, 2005

hey guys,

this is my first post so i would really appreciate all your imput.

my 1994 STS had 147k on it, i beat the car everyday for a year... like 30k miles per year... anyways.... my mom took my car to go get some food and when she started the car it broke.

so far, i cant tell but i think its fatal. i have a 94 TA with a 383 and i know that if i ever herd this sound in my car i'd replace the engine!!!

i cant get to to engine very well because its in the car, i'm gonna pull it but heres the catch!!!

i found a 95 SLS 52k and matching tranny. comes with everything for 650$

i dont care so much about preformance, since its my winter car..

i understand that the cams are different, and the head/intake bolt patteren is also different, but its ODB1 so it should go in right? no wiring harness problems?

RECAP: will a 95 SLS engine and tranny go into a 94 STS?, what problems will i encounter.... i'm not worried about pulling the engine, thats easy:suspense::hmm:

what should i change to make the SLS run good besides tune up... i was thinking a ODB1 SLS pcm.... that way i dont load the car up with fuel!!

1 - 16 of 16 Posts

STS 310

· #2 · Sep 29, 2005

The vin y engine of the SLS does not work well with the STS and the final gearing of the tranny. The PCM might have some issues as well, someone else will be able to go into more detail.

I do know that you will need a compatible vin 9 engine.

mcowden

· #3 · Sep 29, 2005

1994transam said:
hey guys,

this is my first post so i would really appreciate all your imput.

my 1994 STS had 147k on it, i beat the car everyday for a year... like 30k miles per year... anyways.... my mom took my car to go get some food and when she started the car it broke.

so far, i cant tell but i think its fatal. i have a 94 TA with a 383 and i know that if i ever herd this sound in my car i'd replace the engine!!!

i cant get to to engine very well because its in the car, i'm gonna pull it but heres the catch!!!

i found a 95 SLS 52k and matching tranny. comes with everything for 650$

i dont care so much about preformance, since its my winter car..

i understand that the cams are different, and the head/intake bolt patteren is also different, but its ODB1 so it should go in right? no wiring harness problems?

RECAP: will a 95 SLS engine and tranny go into a 94 STS?, what problems will i encounter.... i'm not worried about pulling the engine, thats easy:suspense::hmm:

what should i change to make the SLS run good besides tune up... i was thinking a ODB1 SLS pcm.... that way i dont load the car up with fuel!!

Something doesn't sound right: Your mom just started the car and it "broke." What noise is it making? Before you go swapping motors, let the folks here help you diagnose what's wrong. It might be fixable for less expense and trouble than swapping with an incompatible engine. Just my 2 cents worth...

powerglide

· #4 · Sep 29, 2005

Welcome to the forum.

Do a search on here using the search funtion top left.

I recall reading somewhere about PCM incompatibilities regarding these engines.....forgot the details.

Try to find an STS or Deville Concourse somewhere.

Good luck

powerglide

· #5 · Sep 29, 2005

heres someone selling an sts cheap
http://www.cadillacforums.com/cadillac-classifieds/showproduct.php?product=959&sort=1&cat=3&page=1

not sure if its compatible though.....just thought I'd point it out

STS 310

· #6 · Sep 29, 2005

powerglide said:
heres someone selling an sts cheap
http://www.cadillacforums.com/cadillac-classifieds/showproduct.php?product=959&sort=1&cat=3&page=1

not sure if its compatible though.....just thought I'd point it out

That isnt even a N* engine it is a 4.9

powerglide

· #7 · Sep 29, 2005

d'oh...

zonie77

· #8 · Sep 29, 2005

I didn't save any but there are a few threads that mention what engines interchange. The intakes changed dramatically in 95 I think.

The gearing is different. The 300hp has 3.7 and the 270hp has 3.1. The 270hp with the 3.7 gears would give you great bottom end.

Someone way back did a major amount of work and got a newer (like 2000)engine to work but it required a LOT of custom work.

maydog

· #9 · Sep 30, 2005

Actually a SLS (Y) engine will work fine in a STS (9), I was exploring this option some time back and the resident cadillac engineer at the time said that it would work - in a maf system the engine would notice the different airflows and adjust accordingly. I have done some searching online and it does appear that the swap has been done. The only trouble would be if the 94 uses a MAP system, I think.

This combination is used on the Bonneville GXP, only the exhaust ports on the heads are different I think.

If you want to avoid potential headaches, however, stick with the STS setup.

davesdeville

· #10 · Sep 30, 2005

94 and 95 use a speed density system with a MAP sensor.

The big issue is that Vin 9 engines had 3.71 FDR and Vin Y had 3.11s so you'd need to work the PCM to adjust the shift points whether you use the 94 9 PCM or the 95 Y PCM. Not sure of anyone who will do this for you.

1994transam

Discussion Starter · #11 · Sep 30, 2005

i'm installing a sls powertrain though... so i'm not even going to use the vin 9 tranny...

sls tranny + sls engine = good(what i plan on doing)
sls tranny + sts engine= bad
sts tranny + sls engine= good(sts tranny has 147k, cant see using this setup)

if the sts harness will hook up, i'm not going to have a problem.... reguardless... i have a 94 sls computer with harness also.....

i just wanna know if everythings gonna hook up, after all its all ODB1 and the same pcm is used from 93-95 so

1994transam

Discussion Starter · #12 · Oct 7, 2005

so guys,

whats the verdict.....

should i grab a sls computer for the swap or just let the STS ecm figure it out?

maydog

· #13 · Oct 9, 2005

I think you will need a sls computer with that setup since the STS computer will notice that the gear ratios are off and start throwing codes.

delzy

· #14 · Oct 9, 2005

Correct me if I'm wrong, but I think you are talking about needing the correct EEPROM (chip), not the computer. I think the computer is the same for all OBDI years.

1994transam

Discussion Starter · #15 · Oct 18, 2005

i did the swap, no problems other than i need a sls pcm...

i'll fill ou guys in on everything

zonie77

· #16 · Oct 18, 2005

OK, were waiting!

1 - 16 of 16 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.