As they are both third generation S cars I see no fundamental reason why this could not be done. However trying to pair a 5 speed from DOHC with an SOHC engine did you with some weird gear ratios that don't match The power output of the engine. Yes it's been done. It will leave you with a permanent check engine light for incorrect gear ratios If you leave DOHC harness in and take only the PCM and BCM from the SOHC.

Come to think of it, you would want to BCM from the receiving car to stay put so that it is already programmed to match the car it is sitting in. I think you would want the PCM from the SOHC to run the SOHC engine.

It would be much easier to take the engine and trans together along with the PCM from the SOHC and put them in the body of the DOHC.

I know that's not what you asked about nor what you necessarily want, but it simplifies so much. Probably the wiring harness too.

I am not a third generation S car guru. I know first and second generation. There may be other strange **** that has to do with how they routed different things of the engine or under the hood like location of exhaust etc.

Please do not take the above as gospel. Like I said, it can be done to do a manual swap. Most people do it by keeping the engine and changing the transmission whereas you are going in the opposite direction to which component you are swapping.

Like anything else it is a matter of tracking down all of the differences and I mean all of them. To answer your boat in questions, yes all s car engines bolt in..

Please do some further research. Sixthsphere.com has a wealth of information. Saturnfans has a crapload of information posted by many people don't know what the **** they're talking about. There are a few experts. You'll figure that out after 5 hours of searching who keeps coming up with the right answers.

Feel free to stop back with additional questions. Ask them before you start because you don't want to be 90% done and suddenly realize it's not going to work.

 

Thanks for this information, very helpful. I have a good running SL! engine already, hence the reason for my interest in the change. Its auto trans condition is unknown, and I vastly prefer the 5 speed anyway, hence the desire to keep the 5 speed. Your comments led me to explore if my timing chain slip is just what I think it is. I pulled the cam cover and it appears as if all the valves are up against the roller/lifters, making me think maybe none are bent. I wanted to pull the lower pulley off to be able to inspect timing mark alignments, but I can't get that crank bolt loose yet, even with a super long breaker bar or my air-hammer wrench. I may have to tow it to a friend's to use a more powerful one. At this point, if it is reasonable to think I don't have bent valves, I'll just replace the timing chain and guides rather than change out the engine.

 

What do the valve and piston movements look like if you rotate the engine by hand? If you choose to do this, do it very very very very very very slowly at the beginning just in case there is a valve hanging out where it will get crunched by a piston. This is not something you have to do but if you find interference on this interference engine then you know the valve train is likely history.

 

I've often used a long breaker bar against the ground to break crank bolts loose. Just make sure you have it on the correct side of the engine for when it rotates to break it loose and NOT tighten it. If your engine rotates clockwise like most engines do, then you want the breaker bar on the right side (grille side) of the car against the ground. That way when the engine rotates clockwise, your socket should turn the crank bolt counter clockwise.

 

More progress, I had my weight lifter son help pull on the breaker bar to break the crank pulley bolt loose, but it held firm despite his strength. I jacked the pressure up to 140, the max of my air tank and by golly, the pneumatic wrench just barely got it loose! I did not have any excess looseness in the timing chain between the two cam sprockets which I thought a little strange for what I thought would be a chain loose enough to skip a tooth. As outlined in another thread, with the two cam sprockets at noon, I see the crank keyway is exactly at noon too. Without the chain looking loose up by the sprockets, and the positions of both cams and the crank appearing to be correct, I have a mystery on my hands I think. I took a compression check; only have 25, 50, 50, 85 psi in the cyls, so my thought that the engine was cranking over too freely was correct. But the question is, what happened? This is a saturn that ran great giving no hints of failure to come. To recap, one morning I started it, it started quickly as it always does, ran for about 1 second and died, just as if I had turned off the switch. Strange I thought, as this car had no stalling issues, quirks, etc. Upon trying to restart it, it cranked over just as if it had uneven and low compression so I immediately thought the timing chain had skipped and quit trying to turn it over. Now with this info I've uncovered, it seems as if the chain is intact and fine. But why then, the low compression in all 4 cyls?

 

How are you checking the compression? Wet or dry? If it's that low, then either most of your valves are screwed up or you have a serious ring problem. I'd pull the head and check the valves for excessive carbon build up. And while you have the head off, raise each piston to the top of the cylinder and check for side to side movement. This all sounds very strange to me, but I'M NOT A MECHANIC by trade. I'm just a disabled old fart who's been working on his own stuff for 50 years.

 

Well, I have continued to puzzle over all this information. This Saturn does have 294k miles. Today I rolled the engine over with the socket on the crank pulley bolt perhaps 8 times and rechecked timing marks which were still right on. I also noted that very slight movement of the crankshaft was enough to move the camshafts, so I became quite certain I've not had a slipped or skipped timing chain. With that assurance, I felt more confidant about trying to start it. Before I started it though, I shot some oil in the cyls with another compression check to discover that the compression did not raise with the oil, so i do have valves that need attention, just not because of having been hit by the pistons. After reassembly, I tried starting it. After great difficulty it did start, suddenly cleared itself, and started running seemingly perfectly like it always has. Must have been a sensor raising humbug. Now it starts readily, and runs and drives fine. I now know it needs a valve job, but I can't believe how strongly and smoothly it runs, and how well it starts with such low compression. We have a 16 year old who, this summer, will be getting her license and this one will be her car. I'm looking forward to seeing it turn over to 300,000, likely sometime next winter.

Thanks again for everyone's help.

 

What are the compression readings now? You should be misfiring on all cylinders if they are still the same.

Sounds like a whole bunch of valves were not making their full travel, thus leaving leakage during the compression test.

​​​​​​Was the head without oil for a significant amount of time?

 

compression with or without oil in cyls is still 35, 50 50, 85 respectively. So valves definitely need attention, though not because they are bent. I was amazed how clean under the valve/cam cover is. No sludge, he cam lobes are nice and smooth, as are the rollers between the cams and the valves, etc. Unbelievable condition for 294K miles. And amazing how well it starts and runs on such low compression...

 

All four plugs pulled, wide open throttle, fuel injector fuse removed? Operating temp? Cold?

Try another tester.
Sometimes things are not as they seem.

Given the mileage if it is all on that engine, would expect 170 to 190 op temp and rings adding 10 psi per cylinder minimum to get to those numbers.

Please advise.