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northstar coolant

Started by peter uzzolino, August 04, 2017, 09:03:40 AM

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peter uzzolino

Hello All,                                                                                                                                                           I have just purchased a 2002 Eldorado with 48k, my main concern is the original coolant. I would appreciate some advice on flushing and replacing the coolant and other suggestions on keeping this Northstar running as it should. Also should I service the trans? This is a 2002 ETC Collector Series in very very good shape, which I will show and drive. (not my daily driver)        Thanks Pete                                                                                                                                                                   

TJ Hopland

Dex-Cool was generally 5 years or 150,000 miles.   Classic 'green' was usually 2 years or 30,000 miles.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Dan LeBlanc

When I first bought my deVille, I took it to my Cadillac dealer and had them do it.  Cost was $80 + tax.  By the time I bought the coolant, did it myself, and all that crap, $80 sure seemed cheap.
Dan LeBlanc
1977 Lincoln Continental Town Car

Mike Josephic CLC #3877

You need to do a coolant change and also use the "pellet" sealant additives
due to the age of the coolant.  With a Northstar, this is especially important.
The "pellets" can be purchased at any GM dealer but I'm told that the "Bars
Leak" brand are the same stuff.

The transmission, I would not be concerned about with your car's age and
mileage.

Mike
1955 Cadillac Eldorado
1973 Cadillac Eldorado
1995 Cadillac Seville
2004 Escalade
1997 GMC Suburban 4X4, 454 engine, 3/4 ton
custom built by Santa Fe in Evansville, IN
2011 Buick Lucerne CX
-------------------------------------
CLCMRC Museum Benefactor #38
Past: VP International Affiliates, Museum Board Director, President / Director Pittsburgh Region

peter uzzolino

Thank you all for the help and advice. I hope to keep this beauty running a long time.                                                                 Thanks Pete.

James Landi

Peter, you are very "right" to be concerned-- I would urge you to be mindful about having your radiator flushed by Cadillac service only.   "Stop Leak" has a variety of leak "inhibitors" they market--- some of them can cause your radiator to lose its efficiency (compromised by the systems age) and overheat the engine when it's very hot out, and your car is at idle.   Over time, some coolants become corrosive and generally, old radiators build up crusty formations, as well,  if they are not regularly flushed.  Your challenge with your car is not mileage--- it's the age of the mechanical components and just how much "crusty gunk" is partially clogging the radiator passages.  Early Northstar engine overheat mainly due to neglected maintenance or a well intention person dumping the improper coolant additive into the system.    Hope this helps,    James

peter uzzolino

Hello again, I do think I am going to bring it to cadillac, I am just so unconformable not being able to watch and see what they do and being carful and put things back together right. I do know I need to get it done. Thanks again, Pete.

dochawk

#7
The only vaguely complicated part of doing this yourself is growing a narrow alien tentacle to successfully release the petcock, which GM put where no human can reach it from an angle that allows both twisting and pulling, or reaching with pliers.

I've figured out, I think, how to build a wooden tool to at least turn it, but it may need a tug out after that.

Oh, and I'd be hesitant to put anything in that GM itself (not just the local service department) doesn't list as property.  *Most* of the available things to add to radiator can actually cause harm, including blocking flow and reducing cooling.


hawk
1972 Eldorado convertible,  1997 Eldorado ETC (now awaiting parts swap from '95 donor), 1993 Fleetwood but no 1926 (yet)

Mike Josephic CLC #3877

Here's the GM part number for the pellets.  From the GM service manual:

"GM coolant supplement (sealant) P/N 3634621 specifically designed for use in
aluminum engines. Failure to use the engine coolant supplement (sealant) and the approved coolant antifreeze (Dex-Cool) could result in major engine damage.
When refilling the cooling system, add three pellets of the engine coolant supplement sealant GM P/N 3634621 to the lower radiator hose."

If you take the lower hose off, no need to try to open that %^&* petcock.

Mike
1955 Cadillac Eldorado
1973 Cadillac Eldorado
1995 Cadillac Seville
2004 Escalade
1997 GMC Suburban 4X4, 454 engine, 3/4 ton
custom built by Santa Fe in Evansville, IN
2011 Buick Lucerne CX
-------------------------------------
CLCMRC Museum Benefactor #38
Past: VP International Affiliates, Museum Board Director, President / Director Pittsburgh Region

jdemerson

Peter,

A 2002 Eldorado ETC Collector Series in "very, very nice condition" is a highly desirable model. In my view it is the most collectible Cadillac of the last 15 years. (Some will point to the XLR and XLR-V models here.) Will you keep it a very long time?  Might you put 100,000 or more additional miles on it?

If it has always used Dex-Cool, my instinct would be to continue that with the GM pellets.  I might change it every 3 years or so even though GM's recommendation was every 5 years.

You probably know about the Northstar issues with the head bolts and gaskets. These problems persisted until 2004, though by 2002 they were not as bad as with earlier Northstars. For a car as nice as yours it might be worth addressing it once and for all, especially if you plan to keep the car and drive it. See:

http://www.northstarperformance.com/

Is a car as nice as yours worth a $5000 investment?  Probably almost everyone on this Forum would say "No, just stay away from Northstars through 2003."  You can find tons of posts related to this question. But I think your model is very special, and that in the long run (10 years? 20 years?), it just might have been worth it to have it fixed right. With your mileage, this could probably wait for a few more years and miles. But there are credible reports that Northstars with the head bolts and gasket repairs done right are good for more than 200,000 or even 300,000 miles...

John Emerson
1952 Cadillac Sedan 6219X
John Emerson
Middlebury, Vermont
CLC member #26790
1952 Series 6219X
http://bit.ly/21AGnvn