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2002 Deville
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Can anyone tell me if it would be less expensive to replace the 2002 Northstar engine compared to rebuilding it. Runs great, tired of putting oil (3-4 qts.) between oil changes and using antifreeze now. No leaks and cannot see anything through the tail pipes.
 

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White Diamond '03 DHS (with DTS floor shift)
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Re: need info. please

:welcome:

For the oil consumption problem, go up to the top left of this page (black bar), click on Technical Archive and read up on oil consumption.

As for coolant consumption, are you sure you are consuming it and no leaking it? Radiator side tanks and the surge tank are common leak points. Look for the chalky white telltale residue of dried Dex-Cool.
 

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1992 Fleetwood S&S Hearse, 1993 Buick Roadmaster
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Re: need info. please

It is always best to determine the actual source of your problems before you act. Don't rule out a couple of minor issues causing major problems! I know basically nothing about the N*, so I can't be of a lot of use on the particulars. However, if you know of a good engine dealer or wrecker yard where you can get a good, low mileage motor, I think buying a motor might be the cheaper, and faster, option. But it will depend on availability, demand, and other factors. Have you searched Google for prices on motors, or checked out flea-bay yet?
 

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1998 Seville STS, 2003 Deville
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Re: need info. please

Can anyone tell me if it would be less expensive to replace the 2002 Northstar engine compared to rebuilding it. Runs great, tired of putting oil (3-4 qts.) between oil changes and using antifreeze now. No leaks and cannot see anything through the tail pipes.
I guess it depends on if you're going to do the rebuilding yourself or have it done.

I just rebuilt the engine in my 2001 Deville myself after the head gaskets blew and it was using 4 qts of oil in 3000 miles. Leaking some but most was being burned I think. I had approx. $2300 in parts plus $570 in specialty tools required for some of the operations. I replaced all the bearings, rings, gaskets & heater hoses while the engine was out. New starter, engine belt & all new pulleys for the belt tensioner & idler, water pump and new intake manifold. This also included new axle and torque converter seals and also the TCC solenoid in the transmission. This price included the $550 cost for the Head stud kit & $189.00 Main Bearing stud kit from Northstar Performance. I have approx. 3K mile on it so far and it's not using any oil or coolant.

You can read about my project here. http://www.cadillacforums.com/forums/cadillac-deville-1985-2005-including-1985/532305-engine-removal-out-top-2001-deville.html

From your user name it sounds like you are in Michigan somewhere. I'm in the Grand Rapids area.
 

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97 ETC x2, 04 GXP, 04 STS x2, 97 ESC, 99 Deville, 05 SRX
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We supplied the piston rings for samert as well and I'm glad to hear your oil consumption issues are solved. We've had good luck with Hastings rings.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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Re: need info. please

I know basically nothing about the N*, so I can't be of a lot of use on the particulars. However, if you know of a good engine dealer or wrecker yard where you can get a good, low mileage motor, I think buying a motor might be the cheaper, and faster, option.
Unfortunately even "low mileage" Northstars and Northstar cars are usually in junkyards for one reason - some sort of misdiagnosed cooling problem or more likely, failed head gasket bolt holes in the cylinder block.

A rebuilt, studded 2002 Northstar is nearly bulletproof. BUT - follow the GM service manual top overhaul or major overhaul procedures - too many special torques and procedures to wing it. Head stud job, $1300 - $2,500 depending on shop and parts. Total overhaul - $3500 - $5000 depending.

In either case - head studs or overhaul - the entire drivetrain must come out of the car, so there's a fair share of the labor right there.

Michigan, You might want to study the TSB linked in post #1 of this link, especially the oil fill requirements on P.3. Most owners overfill their oil level and so consume more oil.

http://www.cadillacforums.com/forums/northstar-engines-system-technical-discussion/198220-northstar-ring-cleaning-procedure-proper-oil.html
 

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sorry not really a comment but more a question... with thoughts about rebuilding the original Northeast engine or replacing it? many folks say the jasper replacement engine is the way they do it? Others say to use a rebuilt Northstar? and though I like the way and the mileage i get from the original Northstar engine, I have been told that to rebuild it means a complete tear down of the entire engine, including the lower seals, and maybe even re surfacing the block and heads. Either way, they tell me that means several days of labor charges, and hopefully not finding any cracks in the block or heads, which I have been told may happen if the engine overheats?
Perhaps you may have ideas on the best fix for the head gasket bolt situation, as I like the car, other than watching the temperature gauge climb towards the red line after about 20 miles of driving. Plus, after listen to one mechanic tell me he could do the job but it would be almost an entire week of hands on labor, to rebuild the engine with the larger head bolts.
So, would buying an engine be better or rebuilding the original one, And which rebuilt engine would be the best? The Local Mechanic says he uses the Jasper, but other mechanics say to use the Northstar performance engine. they both have warranties but one is local and the other is 150 miles plus away, not to mention, the shipping charges for the core If I replace the engine?
 

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White Diamond '03 DHS (with DTS floor shift)
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What year is your car?


hopefully not finding any cracks in the block or heads, which I have been told may happen if the engine overheats?
Cracked block or head are very rare. The engine was designed to run without coolant for 50 miles.


I have been told that to rebuild it means a complete tear down of the entire engine, including the lower seals, and maybe even re surfacing the block and heads.
No need to resurface anything. Unless the half case or pan is leaking, there is no need to reseal that either.

That said, just inserting the head bolts and replacing the HG's will require dropping the drivetrain and should cost $2000 - $2500 depending on where you take it (a dealer will be twice that amount), but be sure whoever does it (if you go that route) has done it several times before.

Sounds like you are way up north, but if you can get the car to Joe Blau at Midwest Cadillac repair https://www.midwestcadillacrepair.com/ in Palatine Ill (Chicago suburb), he will do it for around $2200 and has done well over 700 by this time.
 

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2002.5 F55 CORSA STS, 2014 Explorer XLT FWD
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Looks like he's in South Florida.

It's not a case of "larger head bolts" - you use either machined thread inserts in the block holes and use a NEW set of GM head bolts - or you use a set of machined studs fitted into the newly drilled and threaded block bolt holes.

Begins to overheat after 20 minutes of driving - are you losing any coolant? If not, have you checked the coolant purge line for proper flow ? Failing head gasket(s) cause system overpressure which blows off coolant, causing overheating. A clogged purge line allows air bubbles to reach the water pump, causing loss of pumping action which leads to slow overheating.

Before throwing money at it, correctly diagnose the problem.



and, yes - complete overhaul is laborious, with many special tools and procedures required. It takes days of work. You do NOT cut the heads or deck. Maximum allowed head warp is .004", otherwise it's new head time. Study the stickies here in Engines; Northstar.
 

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Thanks for all the great advise, as the Cadillac dealer tells me they prefer not to do the job and the local mechanic tells me to invest in a rebuilt or new Jasper engine, which they say comes with an engine warranty for 3 years, but they tell me it will be several days of hands on labor, just to swap engines.
After Christmas, I will talk with a mechanic some 150 miles away, Jake recommended, who has said it will take a week to do the job, plus longer if other hidden repairs are needed.
Hey, again, thanks for the advise, as a head bolt gasket job sounds better then a new engine, unless, as you have mentioned, the local mechanics are lacking in hands on, Northstar gasket head-bolt repair jobs.
Thanks Again for the information
 

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1994 Diamond ETC N*
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I'll interject that my local independent Cadillac shop, run by a retired racer, absolutely refuses to rebuild Northstars. They will only swap in Jasper engines. Certainly a more expensive solution, but you know you are getting a first rate, assembly line rebuild. With the local guy, who knows?

While I'm here I'll also comment that back in the day the local shop here in town was doing so many Northstars that they eventually developed their own tool, so that instead of dropping the engine out of the bottom, they would instead tilt the engine part way out the top, and then lock it into that position while they accessed the bolts in the back.
 
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