Northstar engine oil cooler

[gdouaire]

Anyone ever retrofitted these OEM engine oil coolers on an Aurora 4.0?  These were apparently used on 90's Northstar-powered Cadillacs . Looks like the oil cooler was either integrated in the radiator, or had a stand-alone radiator.

[Marc]

The oil cooler was separate from the radiator, mounted in front of it.

[sall]

Nope. I deleted the oil cooler on my '96 several thousand miles ago. 95-96 and some 97s had them. Integrated in the radiator opposite side of the transmission cooler lines. On the cadillacs they were incorporated as a 'tow package' IRRC.

[gdouaire]

Feb 7, 2015 11:13:12 GMT -6 sall said:

Nope. I deleted the oil cooler on my '96 several thousand miles ago. 95-96 and some 97s had them.

Any specific reason why you removed the oil cooler?

[sall]

Well the lines leaked and they were god awful expensive at the time to replace.

It was obvious to me at least that the 'cooler' was not needed/added any [noticeable] benefit in factory configuration or they would have been included in later models which only have minor difference. No differences that would matter in this case. I was assuming it had to do with oil formulations. E.G. better additive packages being developed and oil life being extended due to said additive packages. Higher breakdown temp threshold <-- Opinion, not a GM engineer!

From a discussion on a cadillac forum as well..

Earlier model Northstar engines to keep the oil that was commercially available at the time cool enough under heavy duty operation so that it survived. Oil has improved dramatically since 1993. The current SL grades of oil that meet the GF-3/GF-4 specs can easily withstand up to 305 degrees for short periods of time so the oil cooler is really not necessary anymore on a Northstar. That's why it's been totally eliminated on the later model Northstar engines except for trailer towing packages. For normal day-to-day driving without a trailer the oil cooler is just not required on a Northstar so it's fine to remove it if it springs a leak or something.

Deleting has had no noticeable effect on oil life or otherwise. I have a 96 and 98 model so this is based on real world comparison with a Classic, YMMV. I can see an external cooler being beneficial on a tracked car though. Although possibly would just be blocking airflow in an already crowded area on these vehicles.

[randnon]

I have 2 gen 1 4.0's one with and 1 without. I see no need for the oil cooler. These cars already hold about 7+ qts of oil. The cooler lines make it harder for some repairs and my 95 lines are also getting a little ratty. I will also switch the filter housing over to the non cooler version when the lines need changing. BTW I also do some heavy trailer towing ~5000lbs on occasion. They do attach to the radiator with an internal cooler. Rich

[Paulaurora]

How oil cooler lines look like on 2g? where they located ?

[sall]

There are no engine oil cooler lines on a 2nd gen. The radiator may support it and you would have to swap to a appropriate Cadillac oil filter adapter. From a brief search they were used on hearses and limos. Possibly more.

[Paulaurora]

I see Thanks Sall

[gdouaire]

If anyone has such oil filter with cooler lines from an Aurora/Cadillac, I'd be a buyer.

[plato442]

Yeah I changed out the stock oil filter adapter for a new cadillac's oil filter adapter with the two cooling ports, and mouted the oil cooler itself in front of the radiator on the pass side. Tight fit but nice clean install. And no oil leaks.

[tigger]

Feb 16, 2015 22:07:14 GMT -6 plato442 said:

Yeah I changed out the stock oil filter adapter for a new cadillac's oil filter adapter with the two cooling ports...

Part number? I'm mildly interested, lol.

[gdouaire]

This is it:

www.ebay.ca/itm/361213032676

[plato442]

i ordered mine from northstarperformance.com, make sure you tell them its for an Aurora 4.0 and they switch the oil sending unit for the correct one that fits 4.0. Just try to make sure you order from Jake himself, it'll speed up the ordering process (or do it on paypal i guess).

I'm still searching for my pics of the install...

[sall]

Pretty steep IMHO. If there are any 95-97 Auroras at the yard next time I go I will see if I can snag one for someone. That won't be any time soon though. I sold mine $35 shipped after I took it off. Very easy to swap. I believe the 95-98 uses two o-rings as the gasket and the 99+ use a different formed gasket.

What I meant Plato was the lines were old and leaked not the actually adapter. Physically dry rotted/cracked and around the crimped connections.


Here are the line part numbers and rockauto prices. They were both $100+ at one time!

25646229 - INLET - $39.79

25646231 - OUTLET - $63.79

[plato442]

yeah its a bit steep. They used to have them for $55 a few years ago, but I wasn't ready for the project then. I haven't seen any in the yard around here.
Right i hear ya. I would definitely scrap the old lines had they leaked as well!

[gdouaire]

Got a used Northstar oil filter adapter, with oil cooler ports. You will notice that the Cadillac oil pressure sensor has the same threads but is shorter and has 4 connectors instead of 2.

Part number GM 12552619.

[gdouaire]

The in/out ports on the oil filter adaptor look metric. Anyone know what thread it is? Checked on the web but did not find.

[sall]

I listed the part # for the Classic lines. Not sure if you are planning on radiator side tank or a separate cooler? I didn't see the thread listed anywhere either in a hasty search. Sorry can't be of more help.

[tigger]

Feb 24, 2015 8:35:32 GMT -6 gdouaire said:

Part number GM 12552619.

Aug 26, 2011 15:33:19 GMT -6 shelbyracing said:

Housing: 12555005.

?, ...composition change, design change? Very little info on either...

[sall]

#12555007 (w/o oil cooler)
#12555005 (w/ oil cooler)

Are the numbers I have for the Classic. I think whats on the filter housing there is a casting number.

[gdouaire]

Maybe Cadillac's 4.6 had a different GM partno. for their oil filter adapter?

[sall]

You won't find that number on any GM parts lists. At least not in my brief search. Only people reselling used. Pretty sure it is a casting number. Could be wrong have been before. Same part number for 4.6Ls as I have listed.

This product fits 104 vehicle variants.
Cadillac: 9 models, 101 variants between 1993 and 2002.
Oldsmobile: 1 models, 3 variants between 1995 and 1997.

[sall]

Found a picture of the filter adapter w/o cooler I installed.



Just casting numbers. This one was pulled from a '98. Pretty sure I asked AuroraBrain about it at the time and he told me the same thing.