97 SC Engine swap

Hi, new here with a 97 that has a bad case of rod knock. I posted a link to the video of it running at the bottom, have a listen (about 4:30 is when the engine is running) and please let me know if my suspicions are correct. I checked the famous balance (I own an 87 lesabre, and its 3.8 has had 2 balancers already) and found it to be in good shape. I found an engine at a yard that I want to swap into my car, and maybe down the road rebuild my old engine. Alldata makes removing the engine seem really easy, but is it? What am I most likely to have trouble with? Everything looks straight forward, just looks like a couple bell housing bolts are hidden.

Theres only 99k on this car (and I presume its the original engine). What kind of life can you get out of a SC 3800? I don't think this car was well maintained, the trans fluid is pretty bad looking (probably original), the engine compartment is dirty, and the rear brakes are worn down to absolutely nothing. But I got the car for $450, so I can't complain.
Video: https://www.youtube.com/watch?v=UbdCVlRKNK0

You can easily get over 200K with proper maintenance and a few replacement parts here and there. The bottom end is usually good for at least 200K. That engine looks so weird without the plastic cover over the top of it.

Sort of off subject...

How many miles are on your 87 Lesabre? I owned a 88 park ave, and a 90 park ave, and loved them. I'd love to find another one. I too put two balancer on it, along with countless coil packs. It kept on going though, until the bottom end wore out around 330K miles leaving me with no oil pressure at idle that led to a rod failure. I miss that car.

The lesabre has 151k on it. About 10 years ago my father and I pulled the engine and completly rebuilt it. Thats when we learned of the balancer failure the first time. Took it to 2 shops, both said bearings or rods knocking. Only after we got the engine apart did we find the real culprit. Live and learn. The rebuilt engine has 25k on it. I love the way the car drives, and its relatively easy to work on. I don't use it too much, but I spent so much time with it, I can't bear to sell it.

Welcome! It takes a lot of neglect to kill a 3800. They are pretty indestructible in general. Where in CT are you located?

As has been already said, it is very tough to kill the lower end on these 3800's be it a non-SC or SC engine.
You may want to check with a stethoscope or screwdriver for noise at all the rotating components on the passenger side or front of the engine for individual noises. The video does sound like a knock but it's hard to tell from here.
As you mentioned on the video the Harmonic Balancers can go bad and make a lot of noise as well as any one of the pulleys and tensioners, although they tend to squeal, squeak and not knock.
The supercharger is driven by a consumable coupler in the snout and can make a shit load of noise when they wear out. The dealer will tell you the SC needs replacing, that's bullshit. All of it is rebuildable for short money.
You can tell how worn they are by relieving the tension on the SC belt and rotating the pulley back and forth. If you feel any play beyond a 1/16" to 1/8" of an inch you will get noise from that too.
They are replaceable and there are write ups on here as to how to do it and the vendors to get the parts and fluid from. Don't know how much experience with the 3800 SC engine you have but it sounds like you can handle yourself pretty well with a wrench.
Also you mentioned and showed the useless cassette holder in the dash, well you'll be glad to hear that that assembly is removable and a replacement from a 1998 or 99 is a CD holder and fits in the same hole.
All in all you got yourself a good deal and a nice car that is certainly worth fixing.
Spend a bit of time looking at the Index and "Write Ups' section on here, you'll find a great deal of information on this generation of Riviera and a lot of great people on here with a lot of experience willing to help.
Welcome and good luck

moldymac wrote:

The lesabre has 151k on it. About 10 years ago my father and I pulled the engine and completly rebuilt it. Thats when we learned of the balancer failure the first time. Took it to 2 shops, both said bearings or rods knocking. Only after we got the engine apart did we find the real culprit. Live and learn. The rebuilt engine has 25k on it. I love the way the car drives, and its relatively easy to work on. I don't use it too much, but I spent so much time with it, I can't bear to sell it.

Yeah the balancer sounds very similar.

If you ever decide to part with the lesabre for any reason keep me in mind.

GMFreak8 wrote:

moldymac wrote:

The lesabre has 151k on it. About 10 years ago my father and I pulled the engine and completly rebuilt it. Thats when we learned of the balancer failure the first time. Took it to 2 shops, both said bearings or rods knocking. Only after we got the engine apart did we find the real culprit. Live and learn. The rebuilt engine has 25k on it. I love the way the car drives, and its relatively easy to work on. I don't use it too much, but I spent so much time with it, I can't bear to sell it.

Yeah the balancer sounds very similar.

If you ever decide to part with the lesabre for any reason keep me in mind.

Don't see it leaving anytime soon, but you will be hearing from me if anything changes.

I am picking up my replacement next weekend, so I will be working on getting the old one out this week. The one I am getting has 72k on it, could get one with less if they locate another car by next weekend. Is there anything I should do to freshen up before I drop it in? Any seals commonly go?
I am also planning on chaning the trans fluid right away after I get the car running, is it worth my time to pull out the torque converter and attempt to get the old fluid out being that I will be able to get at it easily? or does that just cause more trouble later, like flushing these

deekster_caddy wrote:

Welcome! It takes a lot of neglect to kill a 3800. They are pretty indestructible in general. Where in CT are you located?

I am right outside of Bridgeport near the shore.

moldymac wrote:

I am picking up my replacement next weekend, so I will be working on getting the old one out this week. The one I am getting has 72k on it, could get one with less if they locate another car by next weekend. Is there anything I should do to freshen up before I drop it in? Any seals commonly go?
I am also planning on chaning the trans fluid right away after I get the car running, is it worth my time to pull out the torque converter and attempt to get the old fluid out being that I will be able to get at it easily? or does that just cause more trouble later, like flushing these

If you can change the fluid in the converter, DO IT, and obviosly change your filter. it is just the power flush that seems to dislodge the crap that is holding everything together, sort of speak. basically the flush with the cleaning chemicals can remove the varnish buid up that is actually maintaing a seal on the various pressure solenoids and can also dislodge crap that will cause problems. A little of both from what i've been told by the transmission specialists i've come to know.
That's why mine ended being rebuilt prematurely.
What is the Engine your getting.?
It is out of a supercharged car i hope.??? Actually it has to be as the non-SC is a higher compression ratio with some different internal parts that will cause major problems if you put an SC on a Non-SC or naturally aspirated engine.!!!!!!

Rickw wrote:

moldymac wrote:

I am picking up my replacement next weekend, so I will be working on getting the old one out this week. The one I am getting has 72k on it, could get one with less if they locate another car by next weekend. Is there anything I should do to freshen up before I drop it in? Any seals commonly go?
I am also planning on chaning the trans fluid right away after I get the car running, is it worth my time to pull out the torque converter and attempt to get the old fluid out being that I will be able to get at it easily? or does that just cause more trouble later, like flushing these

If you can change the fluid in the converter, DO IT, and obviosly change your filter. it is just the power flush that seems to dislodge the crap that is holding everything together, sort of speak. basically the flush with the cleaning chemicals can remove the varnish buid up that is actually maintaing a seal on the various pressure solenoids and can also dislodge crap that will cause problems. A little of both from what i've been told by the transmission specialists i've come to know.
That's why mine ended being rebuilt prematurely.
What is the Engine your getting.?
It is out of a supercharged car i hope.??? Actually it has to be as the non-SC is a higher compression ratio with some different internal parts that will cause major problems if you put an SC on a Non-SC or naturally aspirated engine.!!!!!!

The guy at the yard assured me it will be a supercharged engine, not an NA one. I will definitely be draining the TC then, get as much of that old stuff out as possible.

You may already know but, the Lower Intake Manifold (LIM) gaskets are notorious for premature failure.
If it were me i would replace the ones on the new/used engine while it is out regardless if they are leaking or not.
The originals had plastic compounds in them that fail early and cause ingestion of coolant into the intake / engine.
The new design gasket is actually a metal /aluminum type gasket and will not fail prematurely like the originals do.
So, if you are so inclined, get a LIM gasket set, supercharger gasket, valve cover gaskets and two new plastic coolant elbows with o-Rings, available at most parts stores, and start with a fresh gasket set.
Also you are obviously going to have to consider putting new exhaust manifold gaskets on it while doing the swap, do yourself a favor and get OEM GM metal manifold gaskets, they seal properly the first time and last forever. If the existing metal gaskets are in good shape they can be reused. And you can return the replacements after. Some of the aftermarket, even Fel-Pro have been known to leak early. Don't want to have to go back in after a swap and replace gaskets again, they are a pain once the engine is installed.
Most of us that have original LIM gaskets have had to replace at about 100k miles. Some have gotten more miles, some less.

Unfortunately you can spend about $150.00 on gaskets, so you can chose to do it now or later.
But at least give a good close look to the surfaces where the gaskets are on the used motor for signs of leaks.
Although if they steam clean the engine you'll probably loose all witness marks.

Rick, our motors only have one plastic coolant elbow. The W-body L67s have two.

Thanks for the correction.

What year did they stop making the Riv? That'll determine # of elbows. IIRC 2000 was the first year for two. Either way the Dorman 47065 part contains both and you use the o-ring from the second one if you pull the tensioner bracket off.

Holler if you get stuck. I'm in Enfield. Been there, swapped a motor or two.

The coolant elbow you mention, is that the water outlet over the thermostat to the upper rad hose?
And any particular LIM gasket you guys recommend?

My preference is to lookup the LIM gaskets for a 2004 GTP. These are revised, and the core is solid aluminum instead of plastic. Otherwise they are exactly the same shape.

moldymac wrote:

The coolant elbow you mention, is that the water outlet over the thermostat to the upper rad hose?

No, it is a plastic elbow with o-rings on each end located on the passenger side (front) of engine and goes into the LIM.
They tend to break when removing them due to the plastic becoming brittle with age.
They are inexpensive and are worth having around when doing a LIM replacement.
They are available at the parts stores in the "Help" section and the Dorman #47065 is the set i have here in front of me.
I'm preparing for a preventive maintenance LIM gasket replacement in the spring.
I don't have any leaks yet, that i know of, but with over 100K miles I want to change it out to the new (revised) aluminum set.

David,
Also take a look at www.zzperformance.com in their gasket section. When you go to their site just click on the Grand Prix for compatible parts.
You will see the plastic coolant elbows we are talking about as well as the lower intake manifold gaskets (alum).
You can price the stuff and buy it locally or you can order from ZZP as well, if you find them less expensive.
One other gasket that we haven't talked about that is a chronic source of leaks or seeps is the oil pan gasket. They go bad mainly from jacking up the motor with a floor jack under the oil pan which is necessary everytime you want to change Serp belts or some of the pulleys. It seems the gasket will crush and not regain it's shape thereby causing a leak. Look up the "Write Up" on changing belts and pulleys for the Series 2 engine. It requires disassembling the passenger side engine mount and another bracket that necessitates the lifting of the engine slightly.
After i changed mine a couple of times I decided to find an Aluminum oil pan from a later model Pontiac GP that is much more solid, doesn't deform like the OEM tin pans do and doesn't require a gasket, just a small amount of sealant. Cost's the same as a stock pan gasket.
I found it used in excellent condition with everything included for $50.00 on Ebay. Even had the proper GM sealant.
If your new / used engine has been set down on the pan (most likely it has) and has any dent's in it you will probably be dealing with an oil leak or seep after install.
If you choose to replace the gasket you may want to do it after installing the engine as you will probably be needing to jack the engine from the pan to help with engine install.
Or you can do as i did and while the engine is out eliminate the problem completely by finding an Aluminum pan and replacing it while the engine is out. If you do chose to go that route and get a used pan make sure they include the oil pump pick-up tube / screen as it is different than the stock one and is necessary.
If you do a search on here for Oil Pan you should find the references to the pan and years used.
What I paid for the pan complete with shipping is what I've paid just for the stock gasket alone. At the time I found out about the aluminum pans i was about to buy a new OEM metal pan and gasket to try and stop my chronic leaks. That would have cost about $150.00. The alum. pan solved all my problems for only $50.00. Just something else to think about for either now or later down the road.

Thanks for the info guys. I think I will try to find an aluminum pan at some point to avoid replacing that expensive gasket more than once. I guess I'll see what the dealer wants for the gaskets I need being that I will get the exhaust ones there first. Also, my battery vent harness is missing. Is that something I can get at the dealer and use on my battery, or do I need to buy a delco battery that might come with the harness?

I have changed my 1998 3.8 NA Monte Carlo engine 3 times and successfully reused the factory exhaust manifold gaskets on the stock stainless headers, witch I find is a odd piece to be cast iron on my 98 SC riv

ED is correct, if the existing exhaust manifold gaskets are steel, they can be reused if they are in good condition and you can return the ones you bought if you have pre-purchased a set.
If the originals are damaged in any way, replace them. But I've seen stock ones get re-used many times with good success.

98inSFl wrote:

I have changed my 1998 3.8 NA Monte Carlo engine 3 times and successfully reused the factory exhaust manifold gaskets on the stock stainless headers, witch I find is a odd piece to be cast iron on my 98 SC riv

You'll need to consider replacing the restrictive cast manifolds at some point with a set of Stainless Headers.
I and others have used the SSAC Stainless headers made for the regal with good success.
They cost about $300.00 for the set.
Do a search on here using the words "Cheap Headers" and you should find the write up.

98inSFl wrote:

I have changed my 1998 3.8 NA Monte Carlo engine 3 times and successfully reused the factory exhaust manifold gaskets on the stock stainless headers, witch I find is a odd piece to be cast iron on my 98 SC riv

...the Riv manifolds were iron for noise control I think.

Anyone happen to know if the stock SS headers off the Monte fit the RIv? (not that anyone would want them,,,)

Albertj

Heres something interesting. I went to the dealer to get GM exhaust manifold gaskets and they dont show any in the system for that car. Infact, I checked my alldata and it shows nothing between the headers and heads. Is this right?