Opinion(s) on 2001 NorthStar Engine with > 100,000 Miles

[smokuspollutus]

I do like the last gen Eldorado and there are a lot for sale with bad motors. Was thinking of doing the same thing we did with the 4100s, buy them at fire-sale prices and fix, or set aside the money to fix, and have a really nice car for very little money, but any work we did never amounted to more than taking the intake off. I made the mistake once of getting a car in which the engine had to be dropped to do simple things, will never do that again. When the engine is out of the car, what can be done about the oil leaks? Was there ever a revised method of sealing, or is it just re done the way the factory did it? How about the transmission, is that sensor improved? I've inquired from a few different mechanics locally, 2 of 3 won't touch them and the other says about 2k for head gaskets if everything goes well, and another 1k to do all the other stuff you do when the motor is out. I asked if there was any improvement in the oil problems and he said that eventually they all leak, which honestly didn't inspire much confidence in his fix, but it makes sense 

By use oil, I assume that means these burn it (at any mileage)? I've seen a few northstar cars driving that had some blue smoke, but figured that was because they were well worn. Does the oil burning screw up other emissions stuff?

[Caddyholic]

So if the 2001's head gasket has never been replaced, can the 2001's head bolts be changed to the 2004's head bolts to hopefully prevent the head gasket failure?

Thanks,
Matt

I dont think it as easy as just changing the head bolts. The problem is with the head bolt inserts they use. The replacement kits use longer inserts and or coarser threaded inserts. There is also a company selling stainless steel head studs with coarser threads and no inserts.

[Dan LeBlanc]

These guys are the Northstar experts.  Lots of info on their website.

http://www.northstarperformance.com/

[76eldo]

Matt,

No.

The bolts and the matching thread inserts are done with the heads off.  The job really entails dropping the whole front cradle out of the car and working on the engine out of the car.

Trust me, you don't want to get involved with one of these cars unless you love it so much that you are willing to dive in and spend about $5000.  You need to replace a lot of stuff:

1.  Head gaskets with updated fasteners
2.  New coolant metal tubes that run behind the engine at the firewall
3.  Reseal the bottom end
4.  Water pump and hoses and belts, thermostat
5.  Full tune up at 100,000 miles (easy with engine out)
6.  Nice new clean radiator
7.  Replace sure tank that splits when head gaskets are leaking
8.  Trans service

I did all of this plus replaced the air struts that failed and the fuel sender.

I drove it for about 10 months and then a coolant leak came back due to a hairline crack in the front of the block.

So like I said, don't spend more than you are willing to walk away from, just like a 4100.

Brian

[Caddyholic]

And replace the starter that is in the valley under the intake manifold.

[jdemerson]

These guys are the Northstar experts.  Lots of info on their website.

http://www.northstarperformance.com/

Interesting website, and they report selling more than 5500 kits, with many going to Cadillac dealerships.  A complete kit is as follows:
Our "BulletProof Kit" Contains the best parts to ensure your Northstar repair job is successful and durable. What's included?

     - SureGrip Head Stud Kit (complete with installation tooling)
     - Main Stud Kit (direct replacement, no drilling or tapping required)
     - MLS Head Gaskets (Multi-Layer Steel)

With this kit you're studding both critical areas of the aluminum engine block and you're also adding the best head gaskets available on the market.

Package Price: $995.00 USD

One of their kits is for Northstars from 2004 through 2011. Have there been problems with these engines? I had the impression that the Northstars in the XLR, STS, and DTS after 2004 were very reliable. In any event, I think that any of these models with the Northstar V8, and with the full kit installed, would be a terrific car and good for at least 200,000 miles if cared for? Not true???

John Emerson
1952 Cadillac 6219X

[76eldo]

There is a shop in Pottstown Pa run by an ex Cadillac mechanic.
Best in this area.  I have the details of anyone needs it

[dochawk]

Generally speaking, you're going to find better information on northstar, as well as folks that fix them, on cadillacforums than here.  Conversely, once you get to large block and earlier, you won't find much useful there.  (And if you have a 4100, the screws of horror are similar for both).

Anyway, I've gone there for dealing with our northstar cadillacs, and can make some broad summaries.

The northstar put steel deadbolts in an aluminum block, and with too small/flimsy/whatever of threads.  They didn't cut it, and head gasket failure is a result of the bolts losing their grip.

GM made a kit which would use overboard bolts, but dropped it in favor of the third party solutions, which work better.   I forget whether a sleeve is snuck or not.

Anyway, when head gasket failure comes, this is the only solution.

The $3,500 figure comes from other stuff you do as long as the engine is out, anyway.  Generally speaking, after this, they're good for another couple hundred thousand or more.  Come to think of it, I haven't seen any reports of post-repair (done right) failing again, but I've seen sky-high post-repair mileage figures.

This doesn't prevent *other* things from going wrong, and it might take sense to do others while you're at it.

Northstar era cadillacs are still primarily being driven, rather than being saved for shows, and those that want them and fix them are looking for long-term solutions.

My daughter's 2001 DHS is going through some bizarre, probably terminal, overheating at the moment.  It is *not* the head gaskets, apparently, as I've done the block test, and there is no exhaust in her coolant fluids.  Replacing the thermostat made a big difference, but it's still overheating within five or ten miles (already well into the 90s here).

She has oxidized paint, though, down in the red layer of crimson pearl.  It isn't worth doing the expensive work on hers.

My '97 ETC, however, has spectacular paint, as well as almost everything else, just crossed 100k, and I would absolutely drop the $3,500 if/when it comes.  I expect this car to be my daily driver for another 20 years, and I've built that in.

The other fault of the northstar is that the engineers didn't consider the possibliity that it would be driven lightly; they expected it to be driven all-out.  Accordingly, they can build up carbon in the cylinders.   The solution is that a tie or two a month, they should be put in first gear, and accurate at open-throttle to 85 (they will shift as needed, and be in third by then, the shift lever  nothwithstanding). This actually comes from the engineers who designed it; there is a long essay on that site.

Carl had me drive his 400hp mercedes before he left town, and I prefer my ETC in a straight up comparison.

hawk