Hellcat Oil Cooler Buying Guide

TL;DR: On the supercharged 6.2 Gen III Hemi the engine oil cooler is a liquid-to-liquid heat exchanger that lives in the engine valley, under the induction assembly, tied into the oil filter housing. That location is the whole story: the part itself is not expensive relative to what it takes to reach it, and the failure is almost always a seal rather than the cooler core. Because the blower has to come off to get at it, you buy the complete seal kit and every adjacent wear item in one order, not the bare cooler. Confirm the current part number for your exact model year against the manufacturer catalogue before you commit.

Where the oil cooler actually sits, and why that decides your parts list

Gen III Hemi engines package the engine oil cooler in the valley between the cylinder banks, beneath the induction assembly, integrated with the oil filter housing. Engine coolant runs through one side, engine oil through the other, and the two are separated by the cooler core and a set of seals.

On a naturally aspirated Hemi, reaching it means pulling the intake manifold. On a Hellcat, the supercharger occupies that space, so the blower assembly and everything attached to it comes off first. That single fact drives every buying decision on this page. The teardown is the expensive part of the job; the cooler is not.

The practical rule: never buy the cooler by itself. If the engine is going to be open at the valley, the parts order should cover the cooler, every seal and gasket that gets disturbed on the way in, the oil filter, fresh coolant to specification and fresh oil. Start in oil coolers and build the rest of the list around it before you order anything.

How a Hellcat oil cooler actually fails

The core itself rarely splits. What fails is the sealing between the oil side, the coolant side and the block, and there are three distinct symptom patterns worth separating.

Coolant and oil mixing. This is the failure everyone worries about, and it is the one that ends engines. Oil pressure is higher than coolant pressure with the engine running, so an early sign is often oil pushed into the coolant — a film or a brown sludge in the coolant bottle — rather than the classic milky dipstick. Once the engine is shut down and cools, the flow can reverse and coolant migrates into the oil. Either direction means you stop driving the car. Coolant in the oil destroys bearings quickly and quietly.

External seepage. A seal that gives up outward leaves oil or coolant weeping down the rear or the side of the block, sometimes onto the bellhousing, sometimes onto the exhaust where it smokes. It is easy to misread as a rear main seal or a valley pan leak. Clean the area completely, run the car, and find the highest wet point before you buy anything.

Restriction. A cooler that is partially blocked, or a cooler circuit with a stuck or collapsed bypass, shows up as oil temperature climbing higher than it used to on the same drive, or as low oil pressure at hot idle. Do not jump straight at the cooler for a hot-idle pressure complaint — verify the reading against a mechanical gauge and rule out the pump and the pickup first. Pump-side parts live in oil pumps and pickups.

Diagnose which of the three you have before you order. They are not the same repair, and the third one is sometimes not the cooler at all.

What you are actually buying: cooler, housing assembly, or seal kit

Listings for this platform come in three shapes, and mixing them up is the most common reason a job stalls with the car apart.

Two checks before you click buy, both worth more than a price comparison. First, confirm exactly which seals are in the box, because a kit that omits one O-ring you did not know you needed costs you a second day. Second, confirm the current part number for your specific model year and application against the manufacturer catalogue — Gen III Hemi coolers and housings are not interchangeable across the whole family, and the supercharged 6.2 is not the same parts list as a naturally aspirated Hemi. Seals and gaskets for the surrounding teardown are in gaskets and seals.

OEM versus aftermarket on this specific part

This is a sealing part in a location that costs a lot of labour to reach, which pushes the answer harder toward known-good than it would on a bolt-on.

Buy the factory part, or an aftermarket part from a manufacturer that genuinely engineers cooling components, when the failure was cross-contamination. You are paying for the seal geometry and the core, and a second failure means paying the entire teardown again.

Aftermarket is a defensible choice when the brand has a real service history behind it and the kit is complete. What is not defensible is an unbranded cooler or a seal kit with no manufacturer standing behind it. On a part where the labour dwarfs the component, saving on the component is the wrong end of the equation.

One more thing: this is not a performance upgrade path. There is no meaningful power in an oil cooler swap on a stock supercharged 6.2. If you are chasing heat soak and lost timing on back-to-back pulls, that is the low-temperature charge air cooler circuit — a separate loop with its own pump and its own front heat exchanger — not the engine oil cooler. Do not buy this part hoping to fix that complaint.

Doing the job once: what else comes out of the same order

Because the induction assembly is off, the following are either free labour or nearly so, and they are the same age as the part that just failed.

• All disturbed gaskets and seals. Anything the teardown breaks loose goes back new. Reusing a gasket to save a little is how a clean job turns into a comeback.
• Oil filter and a full oil change. Mandatory, not optional, if there was any coolant contamination. Filter and fluid live in oil, coolant and additives.
• Coolant to the correct specification. Use what the service manual specifies for your model year. Mixing coolant chemistries on a system that just had a cross-contamination failure is a bad way to start over.
• Spark plugs. With the blower off, access is as good as it will ever be. If they are anywhere near due, do them now.
• Cooling system inspection. Hoses, the pressure cap and the water pump are the same age and the front of the engine is already accessible. Broader platform parts are in Hellcat 6.2 supercharged parts, and the wider family in Gen III Hemi parts.

On labour, treat this as a serious multi-hour job at an independent shop, longer at a dealer, and longer again if the car has aftermarket induction hardware on it. Get the quote in labour hours rather than as a flat number, so you can compare shops honestly.

Reassembly details that decide whether it leaks again

Three things separate a repair that holds from one that comes back.

Sealing surfaces have to be genuinely clean. Not wiped — clean, dry and free of old gasket material, with nothing scraped into the oil galleries or the coolant passages while you work.

Torque in the factory sequence to the value in the service manual. Valley-mounted components with multiple fasteners and a sealing element are sequence-sensitive. Guessing at torque on a cooler that seals oil against coolant is exactly how a second failure happens. Look the values up for your model year; do not carry over a number from another Hemi.

Fill and bleed properly. Air trapped in the cooling system after this job produces temperature behaviour that gets blamed on the new part. Follow the manual's bleed procedure, then re-check the level after a full heat cycle. Verify oil pressure and check for leaks before the car goes back on the road, and re-check the oil for any sign of coolant after the first few hundred miles if contamination was the original fault.

Frequently Asked Questions

Where is the oil cooler on a Hellcat? In the engine valley, between the cylinder banks and under the induction assembly, tied into the oil filter housing. Reaching it means removing the supercharger, which is why labour dominates the cost of this repair.

What are the symptoms of a failed Hellcat oil cooler? Three patterns: oil and coolant mixing, seen as a film or brown sludge in the coolant bottle or a milky dipstick; an external oil or coolant weep down the block; or rising oil temperature and low hot-idle oil pressure from a restricted cooler circuit.

Can I just replace the seals instead of the whole cooler? Yes, if the core itself is confirmed good and you are only chasing an external leak. If oil and coolant have crossed, replace the cooler — you are already paying the full teardown, and a second failure means paying it twice.

Is coolant in the oil always the oil cooler on a Gen III Hemi? No. The valley oil cooler is a common source, but head gaskets and cracks produce the same result. Confirm the source before you order parts; the teardown is too expensive to do on a guess.

Will a new oil cooler fix my heat soak after back-to-back pulls? No. Charge air temperature on a supercharged 6.2 is controlled by the separate low-temperature intercooler loop, not by the engine oil cooler. Different circuit, different parts.

Should I do the spark plugs at the same time? If they are anywhere close to due, yes. The blower is already off and access will never be better. The parts cost is small next to repeating the teardown later.

How long does the job take? Plan on a serious multi-hour job, longer at a dealer and longer still if the car has aftermarket induction hardware. Ask your shop to quote it in labour hours so you can compare quotes fairly.

Sources

Written against the published architecture of the Gen III Hemi oiling system — the valley-mounted liquid-to-liquid engine oil cooler integrated with the oil filter housing, and the separate low-temperature charge air cooler circuit on the supercharged 6.2 — general Gen III Hemi valley teardown and oil cooler service practice, and our own counter experience with cross-contamination failures, misdiagnosed external weeps and comebacks caused by reused seals on this platform. Torque values, coolant and oil specifications, capacities and part numbers are deliberately not quoted here: pull them from the current factory service manual for your exact model year, and confirm the part number against the manufacturer catalogue before ordering.

Questions on fitment for your car: sales@coretransmissionparts.com. Orders over $70 ship free.