View Full Version : Northstar engine swap 2000 put in a 96 Northstar

11-27-09, 07:43 AM
Hi all.
I got a call, a guy asks me to swap engines. First off, I got no information because some one called on his behalf. The guy finally called me this morning.

Now he tells me he has two Deville's, one 96 and another one 2000. He wants me to swap the engines, take the 96 engine and put it in his 2000 model. He asked if he could use the axels from the 96 car as well. First he talked like both cars were the same type but in the end he finally told me the difference between the cars.

He thinks the engines are the same (both either 275 or 300hp) and was told by another mechanic this would be a no problem.
I wanted to run this before you guys since here are Cadillac experts.

I do have both cars, so if the engine in it's core is basicly the same then perhaps I could go ahead with the engine swap.
But do you have any pointers on what to look out for, what parts on the engine (not inside it) I will need to keep in the 2000 model and what parts on the engine I could leave.
This would be so much easier if I have had the chanse to look at both the cars but this was over the phone and the guy wasn't sure about many things.

So, the question is, is this doable? What to look out for? Is this a easy swap or will I run into problems? Or should I simply call this thing off?

Throw questions at me, and I'll try my best answering them. Worst case I'll call the guy up again and ask him myself.

Thanks in advance!

Regards from Iceland

11-27-09, 09:58 AM
Mechanically, the two years are very different, and that means that the PCM engine/transmission controls are very different also. 2000 was the changeover year to the roller cam follower engine with Coil-On-Plug ignition control cassettes, so the 1996 4-coil/wire/control module system is very different - and that's only the beginning. I believe the 2 engine packages have different motor mounts/bolt holes also. Then you get into different wiring harness connectors because many engine sensors were changed or moved. I have no idea of the differences in transmission controls.......


11-27-09, 11:21 AM
Thanks! I thought this would be a nightmare. Turns out I may have been very correct.

I feel bad for the poor bloke, seems he bought the 96 Deville for engine swaps.
I don't know what the problem is with the 2000 model engine but I will call him up and ask him. Maybe I can fix it for him.

The 2000 model is in so many ways different from the 96.

Thanks again for the technical input. You have been very helpful.


11-27-09, 11:47 AM
ice92, If you are able (from Iceland), you might want to either try locating several years of GM Service Manuals on eBay or subscribe the vehicles in question to www.alldatadiy.com - a most comprehensive online service manual/troubleshoot/recall/technical bulletin service. The (American) Haynes and Chilton's manuals are far too generic for an individual model - just not enough in-depth information. Also, some of the advertised "All manuals in one CD" are not very good, either. I would hazard a guess that doing a drivetrain swap such as you described could also be difficult due to parts availability.

I think one vehicle costs about $20 USD for a year subscription to Alldata, while multiple vehicles and multi-year subscriptions are proportionally less.

If you can get the two cars side-by-side you'll see the considerable differences in the drivetrains.

If necessary you could put in a call to Jake (the Northstar head stud manufacturer) at the phone number in the engines page of www.northstarperformance.com (Canada, Eastern Standard Time) and ask about engine possibilities. He's a very accommodating fellow and really knows his engines.

11-27-09, 05:24 PM
The mounting will work. 2000+ will bolt up to all years of cars. However, the crank position sensor angles, the sensors, and the crankshaft trigger wheel will all prevent the engine from being swapped into a 99 and prior years car. Sure, it'll bolt up. But it won't start. Swapping the crankshaft and sensors will not help. Also, the heads are WAY different. The newer style heads will actually work on a 95-99 car, but the modifications involved to the EGR system, intake, coolant crossover, exhaust, etc., would not be worth the effort. I had plans to do this at one point, but scrapped that idea. The older heads had better exhaust ports anyway- better for porting. 2000+ also no longer have the hole drilled and tapped for the 93-95 knock sensor, which all engines up to '99 did. Just gives you a bit of info on the differences.

When I first got into the Northstars I was planning to do exactly the same thing. Swap a low mileage 2000 L37 into my dad's Deville. Thankfully, the help from these forums kept me from attempting that. It would really suck to bolt the engine into place and then find out there's no way to make it run.

11-30-09, 06:13 AM
Thanks guys for your answers!
I called the guy up again and told him this would be almost undoable and at least a mad nightmare.
He then told me, that the 96 Deville had it's engine swapped few years ago, and IT has a 2000 model engine in it, so the swap shouldn't be a problem!

I promised I would look in to it. I'm thinking getting the car, and try and find the block's serial number.
I think I should be able to find out from what car the engine is in the 96 Deville.
Who should I contact with the block's number? Can any of you here find it out?


11-30-09, 11:00 AM
Like Sub wrote, if it's a 2000+ engine, it will have coil on plug ignition and roller cam followers, just for starters.

11-30-09, 11:30 PM
Like Sub wrote, if it's a 2000+ engine, it will have coil on plug ignition and roller cam followers, just for starters.
Here is 2000+ engine, notice no ignition coil and spark plug wire.

Second picture pre2000 engine (1995-1999 actually) engine with 4 ignition coil pack and 8 spark plug wires

12-04-09, 10:11 AM
Thanks for all your answers! The owner of the 96 Deville insists that the engine is a 2000 model Seville engine and he also claims he has the 2000 tranny. The engine IS 99-down engine and has the 4 coil wire control module system but the 2000 Deville has the roller cam follower.

Now I have been trying to deal with all of this. I came with a solution that would perhaps make all party's involved happy (I was the messenger and it was not fun).

I found another DHS 2000 model, with the engine working, but the car needs other sort of work (body, brakes etc.)
I offered the first guy who bought the 96 Deville to use for engine swaps in his 2000 DHS, the engine from the "new" DHS 2000 model in exchange for the 96 Deville. The owner of the "new" DHS wants the non-working engine also to try and fix it to put in his DHS, and while he's doing the body and engine work he could use the 96 Deville in the meantime.

This was all good until the guy who bought the 96 Deville wants the axels, water cooler and alternator from the 96 Deville to put in his car because these things are all brand new in the 96 Deville.
I know, this is getting very complicated. He bought the 96 Deville thinking it had a 2000 Northstar engine in it, and it would be no problem at all swapping the engines. He also wanted the water cooler and axels because the 96 Deville he thought has a tranny out of a 2000 Seville, so obviously he thinks it will fit his car.
So I'm asking, will the axels and watercooler from the 96 Deville fit his DHS?

The 96 Deville has problems with the tranny, it won't go in fourth. The previous owner of the 96 Deville claims it's because transmission and computer won't match - communication problems.

I know, this is some major drama. :confused:

12-04-09, 02:11 PM
ice92deville, I do not believe the 1996 and 2000 radiators (water cooler) are compatible.

For cross-referencing parts and different years, use www.rockauto.com, get to the proper year and model, then to the system and part. In the part box with descriptions you may click on the small picture or the (!) icon for a larger picture of the part in question.

RockAuto is a good, reliable dealer and the ability to see parts pictures may help your 1996-2000 Northstar dilemma.

12-04-09, 03:29 PM
submariner, thank you ever so much for your input. I think this situation will find it's ground soon. Although I do not think the parts will fit that he is asking for, but we will find a clear ground to land this thing.
I have been reading on this forum and I got a little worried about the head gaskets in the "new" DHS, I think the engine is around 110-120K. Should I abort this mission or go ahead with the engine swap?
I told the owner with the faulty engine that I could perhaps change the head gaskets on his faulty engine and use stud kit but he dismissed the idea.
I then ran that idea over to the guy with the other DHS with the OK engine and he said sure. I just don't want to be in the middle if the head gaskets blow again on the guy with the faulty engine shortly after I swap the engines.
He is a Taxi driver and uses his DHS for that, so the engine runs a lot in idle.

Any pointers, advice or anything else I should be aware of?

12-04-09, 07:54 PM
OK - I'm all confused...but...if you're asking if the head gasket repair is reliable in the long run, the answer is yes. If you do Norms Inserts (OK, and what I used) or Jakes's studs (best, most reliable, most elegant current know solution), chances are the engine will outlive the rest of the car. I have gone only 10K miles since my HG repair, but I think there are people out there that have gone 40-50K miles since HG repair and still going strong. The basic design of the Northstar, especially the 2000+ roller follower design engines, is really a durable design, other than the all too common HG problems that plague even the 2000+ engines (although maybe less than the '96-'99 engines).

12-04-09, 10:39 PM
tateos, thanks for your input. I know this is confusing, I'm even confused. Perhaps the biggest problem here is my English skills, they may not be at it's best, so, when I try to explain things in other language that is already confusing to myself may turn out to be hard to read and follow.
Usually my English skills are fine but when I'm trying to explain something I find hard to explain in my native language it some times gets a bit ... confusing to say the least. :stirpot:

So, I will try to explain this after reading this and seeing how confusing it is put out from me :)

Put it this way. There is the 2000 DHS with a blown head gasket. Let's call it the black DHS since the car is black.
Then there is another 2000 DHS not with a blown head gasket, that car needs other work though and won't hit the streets until next summer. Let's call it the silver DHS since the car is silver.
Then there is the 96 Deville. That car is green, so let's call it the green Deville.

The green Deville once had a owner who has been going with his car on many garages trying to get his car fixed. Finally, some one offers him an engine and a transmission, and claims it's from a 2000 Seville.
That garage does the job on the car, swaps engine and tranny and bills the poor man huge ammounts of money for the job.
The green Deville 96 has problems after that job. Transmission never shifts to fourth and some other minor issues.
The man who owned the green Deville 96 sells the car to the owner of the black DHS (with the blown headgaskets). The owner of the green Deville sold him the car, beliving it has a 2000 model engine and transmission. The buyer and owner of the black DHS thinks this is a sweet deal, he gets an engine he can swap, and a transmission he can own as a spare.

Then they are interduced to me. I started this thread cause I was all confused. At first I didn't know the green Deville had the engine swap so I tell them this is not doable. They insist it is, both have consolted with a third party saying this job is doable. I then started this thread asking if this was REALLY doable.

After consolting with them, telling them I belive it is not doable, they then explained to me the 96 car had a 2000 Seville engine.
At this point I was really confused.
Finally I looked at both cars and saw the green 96 Deville has in fact 99-or older engine.

Feeling bad for both guys I called a friend of mine, the owner of the silver 2000 DHS, knowing his car is not being used at the moment because it needs some work. Offering him the green 96 Deville for the engine in his car and the engine with the blown gaskets that I could repair later.
He accepted.

Then the owner of the black DHS figgures he bought the green Deville not only for it's engine, but also for it's axels (brand new), radiator (brand new) and alternator (brand new). That is how he justiced the purchase for him self in the first place.
I do not think the axels from the green 96 Deville allthough legendy it has a 2000 Seville engine and transmission (wich it has not), the radiator will not fit (I have checked) but the alternator I'm not sure if it will fit or not.

The engine in the silver 2000 DHS does not have a blown head gasket, but the engine has around 110-120K miles on it, so I'm having second thoughts about this arrangement I have made.
I do NOT want the owner of the black DHS come to me after few months with his black DHS with the engine out of the silver DHS with blown head gaskets.
Should I abort this mission (the engine swap between the two DHS's) or should I proceed after carefully explaining to the owner of the black DHS the changes he might be taking.
Perhaps the engine currently in the silver DHS is fine and I'm being paranoid or perhaps I'm being reasonable cautious.

12-05-09, 10:50 PM
Take all 3 or 4 cars and just put them out of their misery. Crush 'em. :lildevil:

12-06-09, 09:58 AM
Destroyer, The guy's in Iceland, trying to make the best of a difficult situation with 3 people breathing down his neck and no parts accessibility. He needs advice, not a stab in the back.

12-08-09, 07:56 AM
Destroyer, The guy's in Iceland, trying to make the best of a difficult situation with 3 people breathing down his neck and no parts accessibility. He needs advice, not a stab in the back.Oh I know but man, what a confusing situation. Not many are prepared for the lack of compatibility between the years of these cars. It's nuts. :hide:

12-08-09, 08:14 PM
OK - if you take the engine out of the Silver DHS to install in the Black DHS, I think you either have to:

A. Remove the heads and do the insert or stud repair, while it is already out of the car,


B. Be prepared to remove the engine in the future and do the repair.

Why do I say this? Because, as many of my fellow members may remember, I replaced a '97 engine with 87K miles on it with blown head gaskets with a used '97 engine with good head gaskets and 89K miles on it, and then 23K miles later, THAT engine experienced HG failure. I replaced rather than repaired the first engine because of my ignorance about what I now consider a common, widespread problem. I know people will chime in about how they went 100s of thousands of miles with no HG problems, but I can only speak from my experience, and my experience has been 100% failure. I also have a 2000 DTS that was originally my father's car and that car had to have the original engine changed when it was around 2 years old because it was leaking coolant on the garage floor. I did not live near the car then, so I was not directly involved or know any details, but all I know is the entire engine had to be replaced under warranty. Was this another HG failure? Maybe?

Both options A and B have their merits, but if it were me, I would do the HG repair, half case and/or oil pan re-seal, if needed, and definitely the coolant crossover seal replacements.

But, why not just do the repairs on the engine in the black DHS and then re-install it in the original car? That engine will last a long time. Maybe I missed something along the way?

12-09-09, 07:38 AM
tateos, thanks for the advice.
I already gave him these options, seems like he just wants the engine out of the silver DHS and in his black one.
When I offered him to do the HG job before installing the engine in his car he simply replied: "Does the silver DHS also have blown HG's?"
I explained to him the HG is a common problem in the N* engines, and he said he knew that. I also explained the head bolt failures and told him about the Sure Grip studs.
I offered him to a) repair his original engine with the studs, b) remove the heads off of the silver DHS and insert the studs to prevent HG failure.
He just wanted the engine out of the silver DHS, and told me we would tackle the HG's later if they would blow.
I then explained to him I could not be held responsible if the HG fails soon after the engine swap.

Thank you all for your inputs. You have been very helpful.
I plan on buying the Sure Grip studs to repair the engine out of the black DHS and put it in the silver DHS sometime early next year since there's no rush on the silver DHS.
I also registered on the alldatadiy.com as submariner409 pointed out to me, a very nice site and good info.

Thanks again!

12-12-09, 04:54 PM
we would tackle the HG's later if they would blow.


Spend a few hundred now, or a few grand later; the customer is always right, even when they're wrong. I admire your patience.

03-04-10, 04:08 PM
I would like to know if a 96 eldorado 275 hp engine will work in a 97 ETC. Any info would be appreciated.

03-04-10, 09:19 PM
Without a doubt. Change the intake cams if you can to make it a VIN 9 engine. Other than that, 100% compatible/interchangeable.

03-04-10, 10:10 PM
Without a doubt. Change the intake cams if you can to make it a VIN 9 engine. Other than that, 100% compatible/interchangeable.

Thanks, that was my next question... I had heard the cams were different. Is that the only difference on the engine or is the performance tweaked more in the ETC's computer?

How hard is it to change the cams?

03-04-10, 11:06 PM
Yeah but you plan on swapping engines, right? Not PCMs... Just the cams in the engine in '97 were different. Valve springs are the same that year from L37-LD8. PCM's are tuned accordingly for the L37/LD8 engine, but any one of the engines L37 (VIN 9), LD8 (VIN Y), or L47 (VIN C, Aurora 4.0) will interchange without any problems whatsoever and run perfectly. You will notice a performance difference though.

10 bolts to change the cam on the right side, 12 on the left side. 10mm head. A 15/16 or 24mm wrench on the end of the cam, and a 1" wrench on the hex casting in the cam. You'll have to reset the timing, unless you're careful with it. 105 ft. lbs. on the cam gear bolt upon retorquing. Check all lifters for wear. Swap all lifters if possible to match the cam you're swapping, all lifters/lobes paired up as they were before. Camshaft assembly lube on all lifters, lobes, and camshaft retaining caps and around the camshaft journals.

04-08-11, 04:28 PM
Howdy, Perhaps a crazy question...but what's involved in putting a 2008 Northstar in the 97 Elorado? some say it will go ok, other say the sensors and othe electics are diffeent. Any thoughts?

04-08-11, 04:46 PM
Dude, do more reading and less posting... there is ABSOLUTELY NO WAY an 08 is going to work in a 97... not without TONS of money and time.

04-08-11, 06:28 PM
I gave you the same answer on the other thread where you asked it. No need to repost all over the forums.

04-08-11, 10:31 PM
Howdy, Perhaps a crazy question...but what's involved in putting a 2008 Northstar in the 97 Elorado? some say it will go ok, other say the sensors and othe electics are diffeent. Any thoughts?

Thoughts ????................... it's all here and in Tech Tips - nice try. It can't be done.