[ParetosFew]

Hello All! Starting to get around to some projects on my 91 Caprice Classic. Radiator has a small leak when everything is heated up so I ordered what I thought was the correct one without engine oil cooler. My understanding was this was only used on the police 9c1 version.

However, I have lines going into the driver side under the main coolant hose. The radiators with engine oil cooler ports seems to have the correct ports, so I'm really looking to confirm that its possible to have it on the civilian version? Haven't found anywhere concrete to confirm it, but looking through some youtube video comments it seems like the lines on the passenger side are for transmission fluid cooling and driver side is oil cooling lines?

Thanks in advance, long over-due introduction post coming soon. Very new to working on cars and came across a friend selling this car with low miles very cheap and thought it would be something great to learn on since I've always liked these big Chevys!

 

[green hose]

Hello All! Starting to get around to some projects on my 91 Caprice Classic. Radiator has a small leak when everything is heated up so I ordered what I thought was the correct one without engine oil cooler. My understanding was this was only used on the police 9c1 version.

However, I have lines going into the driver side under the main coolant hose. The radiators with engine oil cooler ports seems to have the correct ports, so I'm really looking to confirm that its possible to have it on the civilian version? Haven't found anywhere concrete to confirm it, but looking through some youtube video comments it seems like the lines on the passenger side are for transmission fluid cooling and driver side is oil cooling lines?

Thanks in advance, long over-due introduction post coming soon. Very new to working on cars and came across a friend selling this car with low miles very cheap and thought it would be something great to learn on since I've always liked these big Chevys!

Maybe its the trailer towing package,9C1 under pinning with luxury interior and 3:23 rear gears.

 

[Caddylack]

Maybe its the trailer towing package,9C1 under pinning with luxury interior and 3:23 rear gears.

Is it possible that maybe the 9c1 has an external cooler, whereas the civilian cars run oil through the radiator?

 

[MWP]

Passenger side: lines going into the end of the radiator are for an in-tank transmission cooler. If there is an external cooler on the passenger side, it is a transmission cooler that is in series with the tank.
Driver side: lines into end of radiator are engine oil cooler. If there is an external engine oil cooler (9C1) on the driver's side, it doesn't connect with the radiator at all.

 

[Marky Dissod]

Is it possible that maybe the 9C1 has an external cooler, whereas the civilian cars run oil through the radiator?

Not maybe.
9C1 motor oil coolers (7P8) were always separate and external.
Civilian motor oil coolers (not exactly coolers per se) were integrally attached to the radiator's driver side.
It either came with a separate external motor oil cooler, or a radiator-integral motor oil cooler.
Never both. (5.0L & 4.3L engines might lack both.)

Same idea on the passenger side for ATF, except that every 5.7L V8 came with BOTH a radiator-integral cooler AND a separate external ATF cooler (KD1).
(A very rare option, KNP, uses BOTH radiator sidetanks as integral ATF 'coolers', deleting the motor oil cooler.)

 

[Ken Hennessy]

I have a 96 Caprice with the L99 (4.3l) engine, the driver side radiator tank has the engine oil cooler. This is a low option vehicle. It only has positraction.

 

[ParetosFew]

Should have mentioned car has the 5.0.

Maybe its the trailer towing package,9C1 under pinning with luxury interior and 3:23 rear gears.

I have the original window sticker from this car, it does specifically list the towing package. Regardless of the current issue, which I think I'm clear on (see below), I''d be interested to see more detail about what all the towing package includes.

Is it possible that maybe the 9c1 has an external cooler, whereas the civilian cars run oil through the radiator?

Passenger side: lines going into the end of the radiator are for an in-tank transmission cooler. If there is an external cooler on the passenger side, it is a transmission cooler that is in series with the tank.
Driver side: lines into end of radiator are engine oil cooler. If there is an external engine oil cooler (9C1) on the driver's side, it doesn't connect with the radiator at all.

Not maybe.
9C1 motor oil coolers (7P8) were always separate and external.
Civilian motor oil coolers (not exactly coolers per se) were integrally attached to the radiator's driver side.
It either came with a separate external motor oil cooler, or a radiator-integral motor oil cooler.
Never both. (5.0L & 4.3L engines might lack both.)

Same idea on the passenger side for ATF, except that every 5.7L V8 came with BOTH a radiator-integral cooler AND a separate external ATF cooler (KD1).
(A very rare option, KNP, uses BOTH radiator sidetanks as integral ATF 'coolers', deleting the motor oil cooler.)

These all clear it up for me. I think I had previously read about about the 9C1 version having the external oil cooler and mistakenly thought it was 9C1 = Oil Cooler, Civi = No oil cooler when it's a bit more complicated than that. I do wonder if the 5.0L can lack both, why mine has it, maybe the towing package? Going to do some more research on what options the car has. Regardless, it seems pretty clear that I need a radiator with the ports for the oil cooler.

Thank you, probably a marketplace thread incoming soon for a non oil-cooler radiator.