: 97 Eldo - 4.0 NORTHSTAR - NO POWER?

03-09-07, 05:12 PM
I've got a 97 Eldo, just bought it, and yes it has the 4.0, must have been changed at one point and swapped in from an Oldsmobile Aurora. Anyway, even the 4.0 is rated at 250 horsepower, yet I cannot even get the tires to chirp by take off. Won't spin no matter what I do, just seems that the car should be able to do that. I've tried turning traction ctrl off, and the display confirmed it was off, but still, nothing. Any ideas? It runs great, great response, and I'm getting over 30MPG when driven carefully. Really is a nice car.

03-09-07, 06:05 PM
there is no way in hell that car would work with a 4.0
it may FIT
but the computer will HATE that...

03-09-07, 06:24 PM
Well it is working, could have been a cam cover replaced anyway it says on the cam cover "4.0 NORTHSTAR". I have the funny feeling it is a 4.0. I pulled the codes, and nothing serious. Cleared them all, check engine light went out, I'll take it for a test and see if it has any more power (yeah right) but exactly what can these cars do if they have the 4.6? Can they smoke the front tires with t/c turned off? Are they electronically limited from a dead stop to a certain speed? I doubt Cadillac would ever do that to a car.

03-09-07, 06:29 PM
Disabling T/C will also disable 1st gear.

03-09-07, 06:48 PM
dude you def wanna search about that stuff
you cant lay tire short of using bleach...

03-09-07, 08:29 PM
Yeah- that makes sense- felt like I was taking off in second. Cleared the error codes, left t/c on, and took it for a test. It's doing very well now, but a 0-60 time of around 9 sec, is that right for a 4.6 Eldorado? I've read that 97's had 300 horses, and I've also heard 275. What's the true story? My Eldo has the LD8 option code. I can't really see anybody being crazy enough to shove a 4.0 in place of a 4.6.

03-09-07, 08:43 PM
my ETC is the fastest here without nitrous and i run a 5.6 0-60 and a 14.2 1/4
stock is 6.7 sec and 14.8

in theory anything can be done but i HIGHLY doubt someone stuffed a 4.0 N* in there, the computer would be throwing more than t/c codes...

L37 is the 300 HP N* found in the Eldorado Touring Coupe and Seville TS
LD8 is the 275 HP N* found in the Eldorado Sport Coupe and Seville LS

I have and those times above are for the ETC

03-09-07, 08:53 PM
LD8 = 275 HP (3.11 final drive)
L37 = 300 HP (3.71 final drive)

03-09-07, 09:10 PM
That's great reference. Thanks Ranger.

03-10-07, 07:51 PM
OK I think it might be the original LD8 4.6 Liter engine, someone may have changed the cam cover. I know the LD8 won't have any lettering on the cam cover at all- (mine says 4.0 Northstar 32 valve.... and is not painted just cast aluminum) but on the cam cover facing the back of the engine there is no lettering whatsoever and it is painted black.

Is this normal or does it look like it could be just a different cam cover?
After testing it out a few days (just got the car) it seems to have the V8 muscle that I wanted (but then again I was used to driving a 403c.i. powered Pontiac) and unbelieveable gas mileage- the readout has displayed 35mpg.

Should both cam covers be identical? (same color and lettering)

03-10-07, 08:00 PM
No. Rear cam cover is not visible so it is not prettied up.

03-12-07, 09:43 AM
What is your VEHICLE SPEED when the ENGINE SPEED is at 2000 rpm, in 4th gear? If your vehicle speed is about 60 mph, you have the 3.71 transaxle in there. If your vehicle speed is about 75 mph, you have the 3.11 transaxle in there.

Look at your VIN to determine what the car came with from the factory. The 8th character denotes the engine/transaxle. '9' is the 300 hp/3.71 final drive. 'Y' is the 275 hp/3.11 final drive.

It's certainly possible someone swapped in a 4.0, but that seems unlikely. Having said that, if someone swapped in the 4.0 (which doesn't have as much torque as a 4.6) and your car has a 3.11 final drive, it'll be pretty doggish. Similarly, if someone swapped in a 300 hp 4.6, but your car originally came with the 275 hp 4.6 (along with the 3.11 final drive), your car will be slower, because the 300 hp engine doesn't make as much torque as the 275 hp version, and needs the 3.71 final drive to get up and go.

Write back with the VIN and with your vehicle speed at 2000 rpm in 4th gear. I'm curious.


03-12-07, 09:49 AM
stock is 6.7 sec and 14.8

And to add to that, the times for an LD8 car aren't much different. Typically in the high 6 to 7.0 second range and 1/4 mile in the 15.0 range. My '97 SLS does 0-60 in 6.7, measured with Gtech. The field performance for the two engines (stock) is very similar.

9.0 seconds 0-60 is too slow for a properly operating Northstar.

03-12-07, 09:52 AM
After testing it out a few days (just got the car) it seems to have the V8 muscle that I wanted (but then again I was used to driving a 403c.i. powered Pontiac)

I hear ya there. The Northstar won't have the torque of your old 403. I had an '87 Buick Regal that came with the Olds 307 V8, and I swapped in an Olds 403 out of a '78 Regency 98. Incredible torque. It would lay down above about 4500 rpm, but gobs of torque.

The Olds 403 and Northstar are fundamentally opposites (as you can tell). The Olds will turn the tires easily off the line, but gets flat as the engine speed builds. The Northstar is softer off the line, but screams at high rpm.

That said, both of my Northstar Cadillacs will easily turn the tires over from a stop...until the traction control kicks in, that is.

03-12-07, 03:42 PM
Gtech is unaccurate to say the least
on another forum someone gteched a 97 STS without ANY mods 0-60 in 5.3 seconds...

03-13-07, 07:17 AM
Car & Driver recorded a 6.7 0-60 run for an SLS. I once raced a 1999 Pontiac Grand Prix GTP and both of us were dead-even (and they are supposed to do 0-60 in the high 6s). I Gteched it 3 times and all were very consistent (in the high 6s, with 6.7 being the best).

Others using the very same Gtech (it was a group rental) got very consistent results. Just because one person got an erroneous reading with one meter doesn't mean that ANY report from ANY meter is foul. The results I got are consistent with at least three other sources, so I trust them.

But the point was, and still is, there is a very small difference in performance between L37 and LD8 cars. Regardless of which version 4.6L engine he might have, 9 seconds to 60 is at least 2 seconds too slow, which means something is amiss somewhere.

03-13-07, 08:38 AM
no way was it 6.7...
thats stock ETC time
SLS is heaver and also as you know has the less power...
you sure about that?

and actually if he has the aurora 4.0 it may explain it, the olds was like a 7.5 sec 0-60, add in the fact that the eldo prob weighs about another 1500 pounds, the computer not being set up for a 4.0 (its still thinking its a 4.6 and dumping too much fuel) then 9 sec would see pretty reasonable...

03-13-07, 08:50 AM
no way was it 6.7...


thats stock ETC time

That could be. Actually, I think most STS/ETCs are in the mid 6 second range stock. I think 6.7 would actually be towards the "slow" end for an L37 car.

Check it out: http://www.jnjhome.net/cadillac/images/caddyperf.gif

A '96 STS was 6.4/14.7. A '95 STS was actually also 6.4/14.7.

And truthfully, 6.7 is on the "fast" end for an LD8 car. Besides my own, there are three published times I've seen for an SLS. 6.7, 7.0, and 7.3. Variability in manufacturing and testing/track conditions accounts for the differences there. Average is about 7.0 (as I mentioned previously). Citing those differences in manufacturing tolerances, you could certainly have one particularly "fast" SLS or Eldorado that might be able to outrun one particularly "slow" STS or ETC. Look at the '95 SLS in the chart and compare it to the '97 STS. That one SLS actually posted a faster time than that one '97 STS.

SLS is heaver and also as you know has the less power...

There is a negligible weight difference, and as we know, the SLS has more torque and more power throughout most of the RPM range (below about 5000 RPM), but we've had that discussion before. ;) 0-60, the two powertrains (LD8 and L37) are very very close. Through the 1/4 mile and through a standing mile, top speed limiter notwithstanding, the L37 powertrain will win out because of the better high RPM power (and obviously an LD8 car is limited to 112 because of tires anyway). But down low, the L37 has a lack of torque and power, that is made up by the shorter final drive (3.71 vs. 3.11). So in the end, it's about a wash between the two, in the 0-40 and 0-60 range (and the chart demonstrates that nicely).

you sure about that?

Absolutely. :thumbsup:

03-13-07, 09:07 AM
point still stands though
9 secs could be reasonable for his car...
and my 97 ETC weighs in at 3800 my dads seville 4200... i dont find that marginal lol
and a 95 SLS prob would fair well against a 97 STS, in 96 the added obd2 computers boosed weight, then also in 97 the addition of stabilitrak and larger brakes also added weight
100 lbs = .-1 secs
it can add up

03-13-07, 09:54 AM
and my 97 ETC weighs in at 3800 my dads seville 4200... i dont find that marginal lol

If you're comparing a '97 Eldorado and '98 Seville, you can't. In 1997, the Seville's curb weight was in the 3800-3900 range (very similar to Eldorado). The '98+ Seville (on the G platform) weighs a good 300-400 pounds more than the K platform Seville, and that's why you're seeing a difference.

You're right, the difference between 3800 and 4200 pounds isn't marginal, but that's not the difference between a '97 Eldorado and a '97 Seville. I'd wager my '97 SLS is within 150 pounds of your '97 ETC. You're right -- it's heavier -- but still pretty close.

I have the 1997 Cadillac ordering book at home, so I'll look up the specifications tonight. It'll list the official curb weight of each model.

03-13-07, 04:11 PM
Okay, for what it's worth, according to the 1997 Cadillac media portfolio, the following are the curb weights for 1997 model Northstar Cadillacs:

Eldorado: 3821 lbs.
ETC: 3863 lbs.
SLS: 3900 lbs.
STS: 3900 lbs.
DeVille: 4009 lbs.
DeVille d'Elegance: 4009 lbs.
DeVille Concours: 4052 lbs.

In general, the Eldorado and Seville are within, at most, 79 lbs. of each other. And it's interesting that the heaviest car, the DeVille Concours is only 231 lbs. heavier than the lightest car, the base Eldorado. Obviously, these numbers won't be EXACTLY what any given car might weigh with personal belongings, fuel load, etc, but are close enough to make general comparisons.

The Seville DID really pork out with the 1998 G platform change. But in 1997 and prior, it was a rather lithe machine. I'd say that beginning with 1998, an ETC should be faster than a same-year STS, because of the weight difference you mentioned earlier. But the two vehicles are remarkably close in weight up to and including 1997.

03-13-07, 04:15 PM
then also in 97 the addition of stabilitrak and larger brakes also added weight

Actually, despite the larger brakes in 1997, the total mass of the four suspension corners was reduced by 1.8 lbs. per car (or about 1/2 lb. per corner) through a new aluminum steering knuckle, revised caliper design, and new lower control arm.