I am in the market for my 5th cadi and would like to have some opinions on which engine would be less troublesome. I have owned 3 northstars and know the problems that come along with owning one. I have never owned a 4.9? What do I need to look for when buying one?? any help would be appreciated. thanks

Columbus eh? The 4.9 is by and far rock-solid and I would trust it anyday over the Northstar. However, the out-of-box performance that the Northstar offers can't be beat unless you're into seriously modding a 4.9 liter powered car.

I am in the market for my 5th cadi and would like to have some opinions on which engine would be less troublesome. I have owned 3 northstars and know the problems that come along with owning one. I have never owned a 4.9? What do I need to look for when buying one?? any help would be appreciated. thanksi have a 94 Seville STS,and it's running strong.it pulls harder,and sounds alot better than the 4.9 (chevy motor).the Chevy Push-rod 4.9litre just can't keep up on the interstate.it runs out of breath.Get the 4.6l DOHC N*.You wont be dissapointed.I'd never mess with anything else.:bighead:

I would say that, by default, the 4.9L wins in the reliability dept because it's a much simpler engine and parts are going to be cheaper.

Both the 4.5 and 4.9 remain among the best engines in GM history in terms of warranty repairs. Which is odd, because both are simply upgraded versions of the 4.1 (which I have), which is equally legendary as one of the most troublesome.

Northstars are amazing engines, but somewhat twitchy and tempremental, and almost impossible for the average shade tree guy to work on. Consequently, they're expensive to repair.

The key to getting a good 4.9 - ask for service records! Find out if the oil was changed regularly, and most important, if the anti-freeze was changed every two years and the coolant supplement tabs were added. If it's already had head gaskets or intake gaskets done, so much the better, providing the engine wasn't seriously overheated when they failed.

Best of luck - let us know what you buy!

i have a 94 Seville STS,and it's running strong.it pulls harder,and sounds alot better than the 4.9 (chevy motor).the Chevy Push-rod 4.9litre just can't keep up on the interstate.it runs out of breath.Get the 4.6l DOHC N*.You wont be dissapointed.I'd never mess with anything else.:bighead:

There ain't nothing 'Chevy' about the 4.9 liter, or else I would have had this thing at 450 hp!!! :p

it pulls harder,and sounds alot better than the 4.9 (chevy motor).the Chevy Push-rod 4.9litre just can't keep up on the interstate.it runs out of breath.


I don't know what's wrong with your 4.9 "Chevy", but my 4.9 Cadillac has more than enough breathe for the interstate!

The Northstar is a much better performer. Around town, the 4.9 usually is quicker until about 45, because of the greater amount of low end torque, but the highway performance of the Northstar is insane! 65-80 in the blink of an eye. As a matter of fact, the highway performance of the Northstar is very close to the around town performance of the 4.9.
For example, the 1992 Cadillac deVille Touring Sedan posts a 0-60 of 7.4 seconds with the 200hp 4.9 V8, the 1997 Cadillac deville Concours posts a 0-60 time of 7.1 seconds with the 300hp Northstar V8, which is quite close. But the 0-100 times are something totally different. The 1992 DTS posts a 0-100 time of 26.7 seconds, which to be totally honest, is quite lackluster.
On the other hand, the 1997 Concours posts a 0-100 time of 19.5 seconds, which is pretty damn good.


That being said, the 4.9 is a much more reliable motor. It's much simpler, lower tech, easier to work on, more traditional, and it's not a high performance motor like the Northstar is. I bought my 1992 deVille with 99,098 miles on it, and now I've got 121,730 on it. The only thing thats gone bad on it was the water pump at 119k miles, and thats a routine thing more than anyting. My main beef with the 4.9 is the annoying main bearing thump, which most of the 1991-92 models have due to undersized main bearings for the crankshaft. Other than that, its a pretty damn solid motor.

For example, the 1992 Cadillac deVille Touring Sedan posts a 0-60 of 7.4 seconds with the 200hp 4.9 V8, the 1997 Cadillac deville Concours posts a 0-60 time of 7.1 seconds with the 300hp Northstar V8, which is quite close.

Don't forget that a Deville Concours is close to 500 pounds heavier than a 1992 Deville! It makes a difference!

On a older cadillacs the 4.9 isthe better engine its very solid, its not as fast as a northstar but it does not mean its slow. I still to this day in my 94 deville can still out WOT most cars from a stop or roll in lower mph on most cars. The torque is amazing for such a engine in this heavy cars, at highspeeds I can still cruise at 80 mph all day long easily.

sorry double post :)

i have a 94 Seville STS,and it's running strong.it pulls harder,and sounds alot better than the 4.9 (chevy motor).the Chevy Push-rod 4.9litre just can't keep up on the interstate.it runs out of breath.Get the 4.6l DOHC N*.You wont be dissapointed.I'd never mess with anything else.:bighead:

ummmm......

.....somebody needs to get their facts stright......

Don't forget that a Deville Concours is close to 500 pounds heavier than a 1992 Deville!


That it is! My bad!

Where are you getting that the 4.9 is a Chevy motor from? It's essentially a bigger (and much better) 4100 which is all Cadillac. If I were picking between a 4.9 powered car and a Northstar car I'd go 4.9. I've seen too many people on here with rediculously high repair bills from Northstars. Yeah the Northstar is the performance all star, but the 4.9 is no slouch and compared to my 4100 it would be plenty powerful.

Plus, there are oh so many 4.6L V8's out there. There are only like three 4.9L motors out there: this one, the Ford I-6 truck motor, and Maserati's 4.9 DOHC motor from the '70s and '80s.

Plus, there are oh so many 4.6L V8's out there. There are only like three 4.9L motors out there: this one, the Ford I-6 truck motor, and Maserati's 4.9 DOHC motor from the '70s and '80s.

Chevy (or Olds?) 300CID 4.9 V8 used in the ~1980 TA

Oh yeah, forgot about that one. 210hp & 330 lb/ft If I'm not mistaken.

The 1980 T/A had a Pontiac 301, they only used it for a few years. It wasn't Firebird exclusive either. The 301 had to be one of the worst engines Pontiac ever made.

Technically, the Ford 302 "5.0" is really a 4.9. I guess 5.0 Mustang sounds better than 4.9 Mustang so they blatantly lied on the front fender of the Mustang for a decade. If you mention that to a Ford guy though it's the equivalent of saying that his mom performs sex acts on farm animals.

Do you guys know how to get a 4.1, 4.5, 4.9 to shift from 3 to 2 or 2 to 1? Let go of the gas pedal, then floor the hell out of it. I do it on my 4100, and it goes like a bullet!! It's funny alos, cuz when i hear the 4100 sounding like it's at 4000rpms, i look at the tach, and its only like 2700rpms. I dunno why you guys think that these engines are slow on the highway. Let go of gas pedal and floor it to make the tranny down shift.

floor the gas pedal on an automatic transmission-equiped vehicle and it will down shift.... imagine that....

Do you guys know how to get a 4.1, 4.5, 4.9 to shift from 3 to 2 or 2 to 1? Let go of the gas pedal, then floor the hell out of it. I do it on my 4100, and it goes like a bullet!! It's funny alos, cuz when i hear the 4100 sounding like it's at 4000rpms, i look at the tach, and its only like 2700rpms. I dunno why you guys think that these engines are slow on the highway. Let go of gas pedal and floor it to make the tranny down shift.

These 4.x motors run out of breath on the highway. Not sure exactly why, but it's much different in a Northstar powered Caddy. You've got to go out and drive one of those.

The reason they run out of breath is mainly because of the cam profile, they are mainly set up for torque. Also the northstars have 4 valves per cylinder which really aid them to breath at high rpms.

Between the LT1 and 4.9, the LT1 has much better highway acceleration. Is this mainly due to the cam profile and different valve clearances/ sizes?

its all about the cam and valvetrain, that simple.

The 4.9 isn't too bad on the highway tho....the Coupe holds its own.... after I drove that '98 STS, which is alot faster at speed, I did realize the 4.9 isn't all that bad tho, she'll hit 75 pretty quick.

Yep, I agree, the 4.9 does hold its own. I have a 1993 4.9 and a 1997 northstar. When the revs come up on the northstar it feels more like it has a turbo than anything else, where as the 4.9 as the revs come up starts out feeling a big v-8 at the lower revs and then more like a v-6 over 4k rpms. I think putting a turbo on a 4.9 makes a lot of sense, you could probabley outrun a northstar with the right setup and yet have greater reliability. Surprised Cadillac never thought of that before coming out with the northstar, they would have saved a lot on development costs too.

The 4.9 is more reliable, and as for running out of breath on the highway, it's true, a bone stock 4.9 does lose it way up there. Slap on a CAI and a new muffler, whole different ball game. I've got $100 that says my car will rape anything resembling a stock N* from 0-60, in the 1/4, and 0-100.

i would agree with ghost...my grandfather had a 92 sdv with a custom exhaust (true dual with high-flow cats), and a cai...made all the difference in the world above 3500 rpm.
as much as i love my seville with the 4.9, you can feel it laboring once you cross 4k, with the sdv it pulled like a bitch to redline

I did realize the 4.9 isn't all that bad tho, she'll hit 75 pretty quick.

Yeah up to 75, but then 3rd gear hits then its all gone.

Side note: When I throw it into diagnostic mode and bring up the digital speedo, it shows a big difference in acceleration. For example, I'll give it full throttle at 75 and watch the main speedometer go 75...76....77...78...79, and on the digital speedo, it goes like 75.76.77.78.79 etc etc. Much quicker. I wonder why. Is the main speedo that bad? I know my dad never liked the horizontal speedos, but why?

its still quick in 3rd gear, once it hits 100 it slows down alot.... lotta wind resistance at that speed, and its out of the power band.

probably just the way it appears on the analog speedo when its that high.... dunno

Yeah, up past 70 MPH, the speedo is way off. For example, the analog speedo will read 72 MPH, the diagnostic mode speedo will read 78 or 79. It's that bad.

still better then my old one... if I had the analog speedo reading 75 I was really doing about 88.

Even the digital one is off... when it says 75, in diagnostic mode it says 73.... no idea why that one would be off, and go form being way over, to now under....

oh well... one of those things you take with the car,I know the acutal speed (via GPS) so I now know if I need to add or subtract a few mph... not that big of a deal.

Is the diagnostic mode speedo driven off the wheel speed sensors or what?

dunno.... maybe its the speed sensor in the transmission...

hasn't bothered me enough to look into it... and I don't see myself doing it anytime soon either, not that big of a deal.

Well what drives the speedometer? I thought that was driven thru the tranny.

either the speed sensors on the wheels or the speed sensor in the transmission

to be a 16 valve engine, its just an honor for a 4.9 to be compared to a 32 valve engine like the N*.
I mean of course its going to run out of breath over 4,000 rpm's, its a traditional 2 valve per cylinder V-8.
The 4.9 is mostly a highway cruiser and not a highway racer. If your going to race a 4.9 powered car it has to be on the street, which is where this engine really shines as do most other 16 valve V-8's.
And to say that a 4.9 is quicker off the line than a N* to about 45 is an honor.
I think im going to do the true dual exhaust and cold air intake to let this thing breath a little better up in the rev band.

I wouldn't say all pushrod 16 valve V8's power drops off at highway speeds. The LT1 350 is a great example. The 1995 Impala SS runs a 0-100 in 19 seconds and a 0-60 of about 7.2. The 1999 DeVille Concours runs a 0-100 in like 17 seconds and does the 0-60 in around 7.2. So obviously the Northstar is much better at highway speeds, but the LT1 isn't bad in that 4000 lb car compared to the 4.9 in the 1992 deVille Touring Sedan, which does a 0-100 in like 26.7 if I remember correctly.

either the speed sensors on the wheels or the speed sensor in the transmission

Transmission. Would be interesting to compare the wheel speed sensors, GPS, and vehicle speed sensor readings together.

Also, the speedo is not driven off the transmission. The VSS goes straight into the ECM. IIRC, there was a seperate output for other modules like SSS and ABS from the ECM, then the output for the speedometer. Maybe there is some kind of filtering at work?

Back to the original subject...

Having owned both a 4.9L car (1991 Coupe Deville) and one with a Northstar (1995 Olds Aurora), I can definitely say that both engines have their pros and cons.

Mechanically speaking early Northstars are hard to beat. Except for blowing head gaskets in the early years if the coolant isn't changed and seal tabs added (similar to the 4.9), the engine is bullet proof. The engine's electronics, however, are far from the best. Bad grounds, coil packs, and crank sensors have always plagued the engine. However, these are very easy items to replace, so if you switch these out, you'll be set (this is what I did on my Aurora...it now has 170,000 miles and its still going). I also added a new ground to the engine block.

Northstars also have a penchant for oil leaks. This is a difficult fix. The engine basically has to be removed to fix it since the oil pan is a structural part of the engine--not just a "pan."

Northstars before 1996 or 1997 are MUCH better engines than those made afterwards. GM changed the Northstar around in one of those years and really messed it up. From then on they had oil consumption problems and other mechanical issues. 1993, 1994, and 1995 Northstars are the best.

The 4.9L is a highly reliable engine which is very durable except for the annoying thumping issue. 4.9's also seem to eat fuel injectors and the pressure regulator isn't the best. Water pumps never last past 80k and the EGR must be replaced every 60-70k miles. You also have to religiously change the coolant on these engines as a safeguard against problems.

So basically, it's pick your poison. Having owned both, I can say that both engines are just great for driveability. The 4.9 can't be beat around town, the torque is just sublime, but the Northstar takes off like a rocket past 45 mph. 2nd gear is like heaven for the Northstar (which goes up to 70 mph). I think the car is actually faster from 50-70mph than from 30-50 mph. They are so different, I suggest owning one of each like I did!