That swap has been discussed on this forum a couple of times and their are stickies that can be looked at and maybe the information is there. The knowledge for doing that can be found on this forum and probably will show up. But and the but really is, all of the electronics have to be found and be operational one way or another and when they are found and installed I am sure it is plug and play.
Now you have to deal with probability. What is the probability that you will actually find those things and have them be cost effective, that is that they will work with no damage. The cars are no long in tooth, the reason they are in a salvage yard is that they have become to expensive to run for one reason or another. If something that is electronic does not work can you diagnose it well enough to be able to purchase the replacement part and be sure once done it will be fixed?
Their are many hidden factors in what you want to do, mostly that of insuring that you actually got working parts and all of what is needed.
Where as at the moment you have working parts and if you do a direct swap of the engine (if one can be found) you have all the extra parts that came with it that all ready match your car.
Please be sure I am not against swapping an dual overhead valve engine in, not in the least. But you have seemed to indicate that you have a strict budget to work with and swapping a dual overhead cam engine in successfully and on a strict budget does not ring as if it is the best financial way of repairing the problem.
And then once done? Would a performance increase be worth what ever effort you went through to do it?
And I am not sure it is.
S series Saturns are nice drivers, I enjoy mine. They are not power houses. If your Saturn in a nice car than the engine swap might be worth it, but it might be better off to just consider the fact that with a new single cam engine or a rebuild of what is in it because once done you will have years of nice driving left in it.

 

(rant) I considered the car to be a nice one, and it sits with a wounded engine at just over 95,000 miles because my wife seemed to be a halfwit who refused to check her oil until the light came on, damaging the engine in the process, I told her that all the s series cars used oil, whether at 20k or at 220k miles, and she should check it herself since I was gone about 85% of the time, but she wouldn't so much as raise the hood until some idiot light came on...(/end rant)

yes I consider an engine swap worth the effort if it is reasonably compatible with the rest of the car... I'm not particularly interested in re-pinning every connector in the harness to change engines, but if I can simply plug in the new PCM, and then bolt in the new engine, and connect everything to it, I would consider swapping at least the engine(and trans later)... I like the car well enough to slightly complicate the engine swap, but not enough to spend weeks upon weeks figuring out the wiring, if you catch my drift... The only reason I was asking is I couldn't find the info in three hours searching on this and other forums...

 

As far as I know if you obtain the proper engine control computer and I do not know for sure the year range to make it play nice with the wiring in your car it should be a plug and play change. (I think) That is if you have an automatic then the donor should be an automatic.
The people who run this forum actually know your answer or can point you in the right direction.
(hoping some one will step up to the plate on this)
I have a 94 SL2 Coupe that my goal is to keep running reliably for a long time due the attachment my wife has to the car. It is hers. She has not been able to drive for 5 years now.
I also have a mechanics computer program where I can pull up almost everything that the equivalent of a Chiltons manual has plus some on all cars up to about 2005 with the last couple of years being sparce.
If you do not have any service literature at all I strongly recommend purchasing something from the help section at O'Reilys auto parts or equivalent. Past that I can look things up to add to information available.
There is a Sticky at the top of the S series Sedan thread on Swap Questions and frankly if you wanted to a message sent to Derf or one of the other moderators will probably give you the information you are looking for.
While I have swapped an engine or two and installed a retrofit fuel injection on an engine that initially was designed in 1966 I hesitate to change on a 1994 or newer car an engine that is not plug and play due to the extensive complexity of the electronics now used in automobiles. That I guess is just me. I feel that now the time that has passed by since S series cars were built and the extensive use of the 5W something winter grade oils that became the new standard which can be directly related to the oil consumption reputation that Saturn and other vehicles have developed I think the odds of finding a used Saturn engine that is not an oil burner is pretty thin. I lean towards rebuilding the one you have to insure that it becomes something in good condition. And to keep it that way use a 10W30 or 10W40 engine oil. Living in Phoenix I can and do use a 20W50 Motor oil in all of my cars year around. It will be 107 today.
But nothing I own is an oil consumer either now and I have 4 cars running with over 100,000 miles including the Saturn.
I suggest a message to Derf or SW2CAM or RiION will get the straight information and check the Sticky referred to earlier.
In the mean time I too will look at stickys
I know that swap has been discussed on this forum and the moderators here are quite knowledgeable on the entire Saturn line.
IF I can be of any direct help I will try to do so if asked.
-Uncljohn-

 

I hope you didn't call your wife a halfwit to her face or yell at her.

 

And ur point is? If you have one.

 

I didn't do either of those... Earlier in the thread was the first time I have expressed frustration in the matter. I was driving the car at the time of the engine failure, and her parents swear up and down I was running the crap out of it. I just took the crap from them rather than let it roll downhill(or uphill depending on perspective).

I paid $3500 for the car, and we had it for about 13 months, accumulating 14,000 miles before it's death... It was disappointing to say the least...



But back on topic, anyone that can shed some light on the swap is more than welcome... I can get the engines for the same price, warranty included, so if I could just pay a little extra, get a PCM, and gain the volumetric efficiency and power, then I would be more than glad...

 

There is a sticky at the top of the forum thread for the S series sedan that takes you to here:
http://www.saturnwiki.com/wiki/index...tle=Swap_Guide
It is a comprehensive list of interchangeability.
It does not (or I did not see it address) changing from SOHC to DOHC engines with problems that may occur but it does address a large list of interchange concerns.
You need to look at it.
Why? Because of the number of problems that may occur changing from one year engine to another.
While the PCM MIGHT be no more than a plug and play there are a number of area's where sensors might be different and that may cause wiring problems.
Again, I am not against the idea of changing to a dual overhead cam engine but according to your last explanation of exactly what the car is, an expensive used car that is in excellent shape other than the engine it sure sounds like it is a candidate for a new or rebuilt engine that would give tons of miles and years of service left in it. You have always indicated budget was a concern. Unless some one can confirm that putting a DOHC engine in the car with a minimum of wiring problems AND the PCM is a plug and play deal, as much as I would like to see you do a DOHC swap it just seems to me that keeping an engine in the car that would be a direct swap so that you can screw into it exactly what is on your engine and have it work correctly when done with out aggravation, is a better financial deal. And I don't really know.

 

I have been reading extensively on this topic lately and the ONLY info I have found so far was on differentracing.com, where they mostly cater to folks looking to turbocharge their saturn( a nice idea for the future)... From what I have read(I haven't joined to actually ask), if going manual to manual OR auto to manual, the engine is as simple as finding a healthy one, snagging a compatible PCM, snag a gauge cluster, use the sensors from your car, bolt everything in, make all connections, fire it up and go... But for some reason or another, if going auto to auto, you need the MP7 automatic, because the PCM doesn't like the different gear ratios... Now I don't know how far out of whack things are thrown, from just as simple as a code thrown, and the engine still running fine in closed loop and the trans working okay, or if the TC stops locking up, and the trans goes into limp mode and won't shift gears and won't lock the TC and you just can't drive...


I have also read of people there running super heavy oil due to a damaged bearing from somebody not checking the oil, and daily driving the car with some degree of confidence, so I am at a loss... I have access to a 99 SL2 for parts if I want it, but it has serious transmission issues(the one in the thread I posted about a few months ago, the HCE car), so I am not sure it's even a viable option... I might just "zombie along" the SOHC with 20w-50 running through it for now...

 

You can use any SOHC engine from any year. The block and the head is identical from one year to the next. All you have to do is transfer all the sensors from your present engine to the new engine, the PCM will never notice the difference.

I really don't know why putting a DOHC in would make any difference either as the PCM is mostly just monitoring the feedback loops. The only issue might be that the PCM will shut down the engine at the RPM limit of the SOHC engine instead of the DOHC limit.

 

I think it has something to do with injector timing or something like that... From what I gather, the auto PCMs don't have a rev limit, except with the neutral safety switch active, then it's like 4000 RPM... Apparently, the trans is supposed to shift at the proper point... They say the VSS input versus RPM can throw the PCM for a loop too... If I could find a late model SL2/5speed for a donor, I would do the swap, no issue with a manual trans... Apparently, the manual PCM doesn't care what manual trans is behind it... Your cruise control won't work without the matching trans, but my car never had cruise...