So I bought the car today... Drove it for about half a mile, like normal, without babying it or trying to kill it... The knock seems to have grown slightly worse as a result... Still not louder than what was on the video, but occasionally audible at idle under load(sitting in reverse or drive with the brakes on)... driving under load seems to either hide or stop the knock... I was given a can of STP oil treatment to put in the engine with the fresh oil that I have planned... Just waiting to get paid...

I guess when I started it cold(ish, it was like 85 degrees outside) it only knocked like three times or so, and it held oil pressure(or at least enough to keep the light off)... Don't know what that means though...

 

You might have a cracked flex plate. I had one on an 85 Horizon and it knocked like crazy for a little bit and then would stop and then go again. I didn't actually figure it out. I sold it to a guy who was in desperate need of a car due to a house fire, and a year later it crapped out on him. His mechanic discovered that the flex plate had cracked entirely away from the crankshaft!

 

Not that I don't think it to be possible, but how would it have cracked when I messed the car up? As far as I'm aware, it's either a lifter or a main bearing... Lifter would make sense, as it sounds exactly like when a lifter collapsed in my old ranger, but the first few times I've started the car after letting it sit, it needed about five seconds to build oil pressure... I'm betting on the crank bearing...

 

I'm not saying that's what it is, I'm just speculating. I'm NOT a mechanic and have never claimed to be one. I just go by personal experiences that I've incurred.

 

It is sort of poor speculation at this point in time on what this is with out looking for a problem.
Any time an engine makes any kind of a knocking noise and indicators are that it is also having poor oil pressure there is a basic mechanical problem that is not getting better. Also every time the engine is started and the symptoms repeat what ever is going on is that much worse.
Money has now been spent to salvage what ever the car is worth to the owner with an assumption that salvaging it is worth the time and money on it in the long run.
A fair assumption for the most part.
However, unless time is put into the car now with the objective to either see to it the car is fixed by replacing parts or determine it must have a new engine as an affordable alternative.
This site:
http://www.autopartswarehouse.com/sh...aturn/sl1.html
has them for a touch under $300.00 which is a smoking deal for parts IF there is the capability of doing the work required. It is well with in the back yard mechanics ability to do something like this.
But damage the block by letting something happen to it because a rod lets go or a main bearing spins causing a mechanical problem that requires machine work to fix it the price escalates.
A bad lifter generally starts making noise immediately as the engine starts and does not go away. A main or a rod can make noises under a variety of conditions. The point is every time the engine runs what ever is going on gets worse.
Can it be fixed by putting a heavier oil in with an additive.
NO
it can not.
However something like that might buy time before something more expensive happens but the is all that is being done, is buying time.
I have had most failures discussed at one time or another with a variety of engines including cracked or broken flex plates. Some things can be gotten away with for a long time.
Other things? Consider your self lucky it has not already gone worse.
Time to as it is said:
Defaecate or get off the pot.
Money has been spent, not follow up and fix it.

 

I just got paid today, so I plan on buying a gallon of oil and a filter and seeing what it does to quiet the knock... In the meantime, I plan on looking for a donor drivetrain to swap into this car WHEN this engine dies(not an if question)... I know of an ION that I could probably buy for nearly nothing, but it has been mentioned time and again that such a swap would be stupidly expensive...

 

The only thing that will fit is another S series engine.
By fit that means bolt into place. And the electronics that it has to mate to has to match what you have so a single cam engine has to be found if your engine is a single cam.
something for nothing is a bad deal.
A cheap ion is a waste of what ever it cost to buy it if you plan on using the engine.
And if you are buying a light weight oil that too is a waste of money.
You have two choices:
Finds a replacement S series engine that is wort buying
or
Rebuild the one you have which if something breaks and damages the block it will not be an option.

As to the oil:
Something heavy is a 10W40 or preferably a 20W50
or for the heck of it a gallon of straight 40 weight if you can find it.

 

I say go for a mid weight oil, either 10w30 or 15w40. I am much more of an optimist that many others here and on other boards I visit. It has a good risk/reward ratio. If it doesn't work, then either junk it or overhaul.

 

I was planning on Shell Rotella 15w-40, a bottle of STP oil treatment that I already have, and possibly a battery if the engine quits knocking... The battery in the car is totally screwed... I have to jump the car each time I go to start it...

 

Okay, guys... I'm stumped... I've searched on various Saturn forums (SaturnFans, Sixthsphere, SaturnWiki) for a few hours now, haven't found the info I am looking for... What complications arise from a DOHC heart transplant? I assume I need to find an identical year engine to start, and I would need the PCM...

Would I need to repin any part of the wiring harness?

Would the DOHC PCM play nice with my SOHC auto trans(in the name of cheapness, the MP6 would probably stay for a while, otherwise I would want an MP2)

I don't imagine I would need a new gauge cluster, but could I be wrong?

Anything else I am missing? I am just looking for info that either tells me that this swap is relatively straightforward, or to forget it and try finding a Sx2, either putting a SOHC in the SL1 or scrapping/parting it out...