I'm going to pick up a motor, tomorrow morning. It's a Northstar from a 1999 Eldorado, that was running when pulled and had less than 70k mi.
It's out of the car, but still sitting on the subframe with tranny. I'm told it's missing a few things like the alternator and CPU and also that the harness has been cut.
What should I look for, ask about or what can I do to test anything?
For me, I wouldn't consider it for more than parts and I wouldn't buy it for parts thinking about it. ."Running" doesn't mean it didn't have the head bolt overheating problem. I've got two spare ones that I've pulled myself and came from insurance totals which were obviously accident insurance totals. No it's not known that they won't overhead, but it means they were running and driving when wrecked and you can gather information from the vehicles to determine how well they were maintained and sometimes discover the previous owners to speak with them. I've called previous owners of cars found in junk yards and offered them a free lunch if I could pick their thoughts on the condition of cars and engines they once owned.
There are pick a part places in KC. It's not hard to pull these engines. I suggest you remove the nuts bolts on the eng/trans mounts before dropping the cradle because a couple are hard to get to once it's on the ground. It only takes a couple of hours.
[This message has been edited by sourmash (edited 09-14-2018).]
is the car it came out of nearby? see if the tailpipe area is covered in soot. seen way to many of them thing burn oil like crazy. maybe bring a battery, cables, and a compression gauge? while I have never cranked a starter when engine on a cradle, I have done it on an engine stand.
I hear you, Sourmash. I'm going to also pick up another one that doesn't run due to unknown electrical issues. The long term plan is to properly build it up. This one is just to get the swap in. A failure and rebuild is expected.
Pyrthian, a compression test is a good idea. Thanks for the reminder. Did I read correctly that the starter is under the intake, in the valley? If so, where are the leads outside the motor?
I don't know if it's a wives tale or not, but I've heard that these motors do better with oil consumption when run more aggressively than average.
There are two big problems with Northstars, both of which are hard to detect with the engine not running.
1) Head bolt threads let go, resulting in loss of head gasket seal. This of course renders the engine unusable. The fix is to install steel inserts in the head bolt holes and the fix is permanent.
2) The Northstar has an aggressive hone pattern on the bore walls so that it can live forever at 6500 RPM. When driven by timid grandmothers who never use more than 20% throttle, this extra oil turns into carbon deposits on the rings that reduce oil ring effectiveness and cause the engine to blow oil smoke and burn more oil. While there are "carbon removal" procedures which can be done with the engine assembled, they're not that effective. The real fix is to tear the engine down and clean the pistons and rings by soaking in carb cleaner to remove the carbon, then reassembling. Drive it like you stole it and the problem will never recurr.
[This message has been edited by Will (edited 09-17-2018).]
There are two big problems with Northstars, both of which are hard to detect with the engine not running.
1) Head bolt threads let go, resulting in loss of head gasket seal. This of course renders the engine unusable. The fix is to install steel inserts in the head bolt holes and the fix is permanent.
2) The Northstar has an aggressive hone pattern on the bore walls so that it can live forever at 6500 RPM. When driven by timid grandmothers who never use more than 20% throttle, this extra oil turns into carbon deposits on the rings that reduce oil ring effectiveness and cause the engine to blow oil smoke and burn more oil. While there are "carbon removal" procedures which can be done with the engine assembled, they're not that effective. The real fix is to tear the engine down and clean the pistons and rings by soaking in carb cleaner to remove the carbon, then reassembling. Drive it like you stole it and the problem will never recurr.
Problem is that over-revving the engine increases the likelihood that the head bolts will let go. Damned if you do, damned if you don't. That said, my 2002 Deville has been granny driven and it burns no oil. It does drip a lot though lol.
A resource on Northstars, if you are interested, is the Caddilac forums. Take a look at the Northstar and technincal systems section: https://www.cadillacforums....echnical-discussion/ Good starting body of info for your perusal. Check out the stickys.
Have you decided what transmission you want? Manual or auto 4T80e?
Since its out of the car, look at the following items: -Case-halfs leaking? -Porous aluminum block. Any antifreeze weep stains? -Make sure the block rotates. You can use a socket and breaker bar or charge the starter. There should be a fat + wire that is under the intake that exits out the back area between the block and intake. It may still have an eyelet on the end. -Check the oil for coolant contamination -Check the water for oil contamination
Fix the Northstar head bolt issue and you will have a bombproof engine that will last a long time that gets decent fuel mileage for a 275-300HP engine. Its just a matter of time before one of the heads let loose. We did what Will suggests. We put Norm's steel inserts in our blocks with Volkswagen studs. You can also use Jake's studs specifically made for the Northstar.
I have three Northstar Fieros and like them a lot.
What kind of oil filter adapters have been used to relocate the filter?
There are a couple of different variants used by GM. Most did not have provisions for an oil cooler, but a few did. '04 (I think) and older are retained by two bolts. '05+ added a third.
CHRF made a remote filter adapter plate, but it's nothing but a plate that bolts on to the block with female 3/4" (IIRC) NPT threads on the outside.
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Originally posted by Slabsurfer:
Thanks for the check list! I do think that I've run across the Cadillac forums before and will bookmark it, now.
Permanently installed studs make a future "courtesy pass" on the block deck impossible, thus ensuring you scrap the block if you ever need to update the build. I used standard timeserts with ARP studs for a VW (Kit #204-4204, Qty: 2) and have not had problems. I also used Cometic MLS gaskets, which can be used to tighten up quench clearance and bump compression a little bit.
A resource on Northstars, if you are interested, is the Caddilac forums. Take a look at the Northstar and technincal systems section: https://www.cadillacforums....echnical-discussion/ Good starting body of info for your perusal. Check out the stickys.
I've always found the signal/noise ratio there to be horrendous. You have to already know what you're doing with the engine to separate the bad info from the good. No, '93's did *NOT* have forged pistons.
Problem is that over-revving the engine increases the likelihood that the head bolts will let go. Damned if you do, damned if you don't. That said, my 2002 Deville has been granny driven and it burns no oil. It does drip a lot though lol.
With stock electronics and automatic transmission, over-revving is impossible. Lack of regular coolant replacement is as much responsible for the head bolt thread corrosion situation as anything else. The Northstar's relatively fine M11x1.5 head bolt threads are subject to stress corrosion cracking in the casting alloy the Northstar blocks are made from, while the coarser M11x2.0 threads that the LS (and '05+ Northstars) use does not suffer from that problem.
